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commit 11cb63b0d1a0685e0831ae3c77223e002ef18189 upstream.
As Paolo said earlier [1]:
"Since the blamed commit below, classify can return TC_ACT_CONSUMED while
the current skb being held by the defragmentation engine. As reported by
GangMin Kim, if such packet is that may cause a UaF when the defrag engine
later on tries to tuch again such packet."
act_ct was never meant to be used in the egress path, however some users
are attaching it to egress today [2]. Attempting to reach a middle
ground, we noticed that, while most qdiscs are not handling
TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we
address the issue by only allowing act_ct to bind to clsact/ingress
qdiscs and shared blocks. That way it's still possible to attach act_ct to
egress (albeit only with clsact).
[1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/
[2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/
Reported-by: GangMin Kim <km.kim1503@gmail.com>
Fixes: 3f14b377d01d ("net/sched: act_ct: fix skb leak and crash on ooo frags")
CC: stable@vger.kernel.org
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260225134349.1287037-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e2cedd400c3ec0302ffca2490e8751772906ac23 ]
Whenever an ife action replace changes the metalist, instead of
replacing the old data on the metalist, the current ife code is appending
the new metadata. Aside from being innapropriate behavior, this may lead
to an unbounded addition of metadata to the metalist which might cause an
out of bounds error when running the encode op:
[ 138.423369][ C1] ==================================================================
[ 138.424317][ C1] BUG: KASAN: slab-out-of-bounds in ife_tlv_meta_encode (net/ife/ife.c:168)
[ 138.424906][ C1] Write of size 4 at addr ffff8880077f4ffe by task ife_out_out_bou/255
[ 138.425778][ C1] CPU: 1 UID: 0 PID: 255 Comm: ife_out_out_bou Not tainted 7.0.0-rc1-00169-gfbdfa8da05b6 #624 PREEMPT(full)
[ 138.425795][ C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 138.425800][ C1] Call Trace:
[ 138.425804][ C1] <IRQ>
[ 138.425808][ C1] dump_stack_lvl (lib/dump_stack.c:122)
[ 138.425828][ C1] print_report (mm/kasan/report.c:379 mm/kasan/report.c:482)
[ 138.425839][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[ 138.425844][ C1] ? __virt_addr_valid (./arch/x86/include/asm/preempt.h:95 (discriminator 1) ./include/linux/rcupdate.h:975 (discriminator 1) ./include/linux/mmzone.h:2207 (discriminator 1) arch/x86/mm/physaddr.c:54 (discriminator 1))
[ 138.425853][ C1] ? ife_tlv_meta_encode (net/ife/ife.c:168)
[ 138.425859][ C1] kasan_report (mm/kasan/report.c:221 mm/kasan/report.c:597)
[ 138.425868][ C1] ? ife_tlv_meta_encode (net/ife/ife.c:168)
[ 138.425878][ C1] kasan_check_range (mm/kasan/generic.c:186 (discriminator 1) mm/kasan/generic.c:200 (discriminator 1))
[ 138.425884][ C1] __asan_memset (mm/kasan/shadow.c:84 (discriminator 2))
[ 138.425889][ C1] ife_tlv_meta_encode (net/ife/ife.c:168)
[ 138.425893][ C1] ? ife_tlv_meta_encode (net/ife/ife.c:171)
[ 138.425898][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[ 138.425903][ C1] ife_encode_meta_u16 (net/sched/act_ife.c:57)
[ 138.425910][ C1] ? __pfx_do_raw_spin_lock (kernel/locking/spinlock_debug.c:114)
[ 138.425916][ C1] ? __asan_memcpy (mm/kasan/shadow.c:105 (discriminator 3))
[ 138.425921][ C1] ? __pfx_ife_encode_meta_u16 (net/sched/act_ife.c:45)
[ 138.425927][ C1] ? srso_alias_return_thunk (arch/x86/lib/retpoline.S:221)
[ 138.425931][ C1] tcf_ife_act (net/sched/act_ife.c:847 net/sched/act_ife.c:879)
To solve this issue, fix the replace behavior by adding the metalist to
the ife rcu data structure.
Fixes: aa9fd9a325d51 ("sched: act: ife: update parameters via rcu handling")
Reported-by: Ruitong Liu <cnitlrt@gmail.com>
Tested-by: Ruitong Liu <cnitlrt@gmail.com>
Co-developed-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260304140603.76500-1-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a4c2b8be2e5329e7fac6e8f64ddcb8958155cfcb ]
When/if a NIC resets, queues are deactivated by dev_deactivate_many(),
then reactivated when the reset operation completes.
fq_reset() removes all the skbs from various queues.
If we do not clear q->band_pkt_count[], these counters keep growing
and can eventually reach sch->limit, preventing new packets to be queued.
Many thanks to Praveen for discovering the root cause.
Fixes: 29f834aa326e ("net_sched: sch_fq: add 3 bands and WRR scheduling")
Diagnosed-by: Praveen Kaligineedi <pkaligineedi@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20260304015640.961780-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit e35626f610f3d2b7953ccddf6a77453da22b3a9e upstream.
Offloading ETS requires computing each class' WRR weight: this is done by
averaging over the sums of quanta as 'q_sum' and 'q_psum'. Using unsigned
int, the same integer size as the individual DRR quanta, can overflow and
even cause division by zero, like it happened in the following splat:
Oops: divide error: 0000 [#1] SMP PTI
CPU: 13 UID: 0 PID: 487 Comm: tc Tainted: G E 6.19.0-virtme #45 PREEMPT(full)
Tainted: [E]=UNSIGNED_MODULE
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
RIP: 0010:ets_offload_change+0x11f/0x290 [sch_ets]
Code: e4 45 31 ff eb 03 41 89 c7 41 89 cb 89 ce 83 f9 0f 0f 87 b7 00 00 00 45 8b 08 31 c0 45 01 cc 45 85 c9 74 09 41 6b c4 64 31 d2 <41> f7 f2 89 c2 44 29 fa 45 89 df 41 83 fb 0f 0f 87 c7 00 00 00 44
RSP: 0018:ffffd0a180d77588 EFLAGS: 00010246
RAX: 00000000ffffff38 RBX: ffff8d3d482ca000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffd0a180d77660
RBP: ffffd0a180d77690 R08: ffff8d3d482ca2d8 R09: 00000000fffffffe
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000fffffffe
R13: ffff8d3d472f2000 R14: 0000000000000003 R15: 0000000000000000
FS: 00007f440b6c2740(0000) GS:ffff8d3dc9803000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000003cdd2000 CR3: 0000000007b58002 CR4: 0000000000172ef0
Call Trace:
<TASK>
ets_qdisc_change+0x870/0xf40 [sch_ets]
qdisc_create+0x12b/0x540
tc_modify_qdisc+0x6d7/0xbd0
rtnetlink_rcv_msg+0x168/0x6b0
netlink_rcv_skb+0x5c/0x110
netlink_unicast+0x1d6/0x2b0
netlink_sendmsg+0x22e/0x470
____sys_sendmsg+0x38a/0x3c0
___sys_sendmsg+0x99/0xe0
__sys_sendmsg+0x8a/0xf0
do_syscall_64+0x111/0xf80
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f440b81c77e
Code: 4d 89 d8 e8 d4 bc 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa
RSP: 002b:00007fff951e4c10 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000481820 RCX: 00007f440b81c77e
RDX: 0000000000000000 RSI: 00007fff951e4cd0 RDI: 0000000000000003
RBP: 00007fff951e4c20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff951f4fa8
R13: 00000000699ddede R14: 00007f440bb01000 R15: 0000000000486980
</TASK>
Modules linked in: sch_ets(E) netdevsim(E)
---[ end trace 0000000000000000 ]---
RIP: 0010:ets_offload_change+0x11f/0x290 [sch_ets]
Code: e4 45 31 ff eb 03 41 89 c7 41 89 cb 89 ce 83 f9 0f 0f 87 b7 00 00 00 45 8b 08 31 c0 45 01 cc 45 85 c9 74 09 41 6b c4 64 31 d2 <41> f7 f2 89 c2 44 29 fa 45 89 df 41 83 fb 0f 0f 87 c7 00 00 00 44
RSP: 0018:ffffd0a180d77588 EFLAGS: 00010246
RAX: 00000000ffffff38 RBX: ffff8d3d482ca000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffd0a180d77660
RBP: ffffd0a180d77690 R08: ffff8d3d482ca2d8 R09: 00000000fffffffe
R10: 0000000000000000 R11: 0000000000000000 R12: 00000000fffffffe
R13: ffff8d3d472f2000 R14: 0000000000000003 R15: 0000000000000000
FS: 00007f440b6c2740(0000) GS:ffff8d3dc9803000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000003cdd2000 CR3: 0000000007b58002 CR4: 0000000000172ef0
Kernel panic - not syncing: Fatal exception
Kernel Offset: 0x30000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
---[ end Kernel panic - not syncing: Fatal exception ]---
Fix this using 64-bit integers for 'q_sum' and 'q_psum'.
Cc: stable@vger.kernel.org
Fixes: d35eb52bd2ac ("net: sch_ets: Make the ETS qdisc offloadable")
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/28504887df314588c7255e9911769c36f751edee.1771964872.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit be054cc66f739a9ba615dba9012a07fab8e7dd6f ]
Commit 38a6f0865796 ("net: sched: support hash selecting tx queue")
added SKBEDIT_F_TXQ_SKBHASH support. The inclusive range size is
computed as:
mapping_mod = queue_mapping_max - queue_mapping + 1;
The range size can be 65536 when the requested range covers all possible
u16 queue IDs (e.g. queue_mapping=0 and queue_mapping_max=U16_MAX).
That value cannot be represented in a u16 and previously wrapped to 0,
so tcf_skbedit_hash() could trigger a divide-by-zero:
queue_mapping += skb_get_hash(skb) % params->mapping_mod;
Compute mapping_mod in a wider type and reject ranges larger than U16_MAX
to prevent params->mapping_mod from becoming 0 and avoid the crash.
Fixes: 38a6f0865796 ("net: sched: support hash selecting tx queue")
Cc: stable@vger.kernel.org # 6.12+
Signed-off-by: Ruitong Liu <cnitlrt@gmail.com>
Link: https://patch.msgid.link/20260213175948.1505257-1-cnitlrt@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit cabd1a976375780dabab888784e356f574bbaed8 ]
skb_header_pointer() does not fully validate negative @offset values.
Use skb_header_pointer_careful() instead.
GangMin Kim provided a report and a repro fooling u32_classify():
BUG: KASAN: slab-out-of-bounds in u32_classify+0x1180/0x11b0
net/sched/cls_u32.c:221
Fixes: fbc2e7d9cf49 ("cls_u32: use skb_header_pointer() to dereference data safely")
Reported-by: GangMin Kim <km.kim1503@gmail.com>
Closes: https://lore.kernel.org/netdev/CANn89iJkyUZ=mAzLzC4GdcAgLuPnUoivdLaOs6B9rq5_erj76w@mail.gmail.com/T/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260128141539.3404400-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 205305c028ad986d0649b8b100bab6032dcd1bb5 upstream.
Replace comma between expressions with semicolons.
Using a ',' in place of a ';' can have unintended side effects.
Although that is not the case here, it is seems best to use ';'
unless ',' is intended.
Found by inspection.
No functional change intended.
Compile tested only.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251112072709.73755-1-nichen@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 27880b0b0d35ad1c98863d09788254e36f874968 ]
tcf_ife_encode() must make sure ife_encode() does not return NULL.
syzbot reported:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
RIP: 0010:ife_tlv_meta_encode+0x41/0xa0 net/ife/ife.c:166
CPU: 3 UID: 0 PID: 8990 Comm: syz.0.696 Not tainted syzkaller #0 PREEMPT(full)
Call Trace:
<TASK>
ife_encode_meta_u32+0x153/0x180 net/sched/act_ife.c:101
tcf_ife_encode net/sched/act_ife.c:841 [inline]
tcf_ife_act+0x1022/0x1de0 net/sched/act_ife.c:877
tc_act include/net/tc_wrapper.h:130 [inline]
tcf_action_exec+0x1c0/0xa20 net/sched/act_api.c:1152
tcf_exts_exec include/net/pkt_cls.h:349 [inline]
mall_classify+0x1a0/0x2a0 net/sched/cls_matchall.c:42
tc_classify include/net/tc_wrapper.h:197 [inline]
__tcf_classify net/sched/cls_api.c:1764 [inline]
tcf_classify+0x7f2/0x1380 net/sched/cls_api.c:1860
multiq_classify net/sched/sch_multiq.c:39 [inline]
multiq_enqueue+0xe0/0x510 net/sched/sch_multiq.c:66
dev_qdisc_enqueue+0x45/0x250 net/core/dev.c:4147
__dev_xmit_skb net/core/dev.c:4262 [inline]
__dev_queue_xmit+0x2998/0x46c0 net/core/dev.c:4798
Fixes: 295a6e06d21e ("net/sched: act_ife: Change to use ife module")
Reported-by: syzbot+5cf914f193dffde3bd3c@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6970d61d.050a0220.706b.0010.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yotam Gigi <yotam.gi@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260121133724.3400020-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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qfq_rm_from_ag
[ Upstream commit d837fbee92453fbb829f950c8e7cf76207d73f33 ]
This is more of a preventive patch to make the code more consistent and
to prevent possible exploits that employ child qlen manipulations on qfq.
use cl_is_active instead of relying on the child qdisc's qlen to determine
class activation.
Fixes: 462dbc9101acd ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260114160243.913069-3-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 50da4b9d07a7a463e2cfb738f3ad4cff6b2c9c3b ]
Design intent of teql is that it is only supposed to be used as root qdisc.
We need to check for that constraint.
Although not important, I will describe the scenario that unearthed this
issue for the curious.
GangMin Kim <km.kim1503@gmail.com> managed to concot a scenario as follows:
ROOT qdisc 1:0 (QFQ)
├── class 1:1 (weight=15, lmax=16384) netem with delay 6.4s
└── class 1:2 (weight=1, lmax=1514) teql
GangMin sends a packet which is enqueued to 1:1 (netem).
Any invocation of dequeue by QFQ from this class will not return a packet
until after 6.4s. In the meantime, a second packet is sent and it lands on
1:2. teql's enqueue will return success and this will activate class 1:2.
Main issue is that teql only updates the parent visible qlen (sch->q.qlen)
at dequeue. Since QFQ will only call dequeue if peek succeeds (and teql's
peek always returns NULL), dequeue will never be called and thus the qlen
will remain as 0. With that in mind, when GangMin updates 1:2's lmax value,
the qfq_change_class calls qfq_deact_rm_from_agg. Since the child qdisc's
qlen was not incremented, qfq fails to deactivate the class, but still
frees its pointers from the aggregate. So when the first packet is
rescheduled after 6.4 seconds (netem's delay), a dangling pointer is
accessed causing GangMin's causing a UAF.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: GangMin Kim <km.kim1503@gmail.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260114160243.913069-2-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3879cffd9d07aa0377c4b8835c4f64b4fb24ac78 ]
Fixes qfq_change_class() error case.
cl->qdisc and cl should only be freed if a new class and qdisc
were allocated, or we risk various UAF.
Fixes: 462dbc9101ac ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Reported-by: syzbot+07f3f38f723c335f106d@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/6965351d.050a0220.eaf7.00c5.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20260112175656.17605-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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qfq_reset
[ Upstream commit c1d73b1480235731e35c81df70b08f4714a7d095 ]
`qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class
itself is active.
Two qfq_class objects may point to the same leaf_qdisc. This happens
when:
1. one QFQ qdisc is attached to the dev as the root qdisc, and
2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get()
/ qdisc_put()) and is pending to be destroyed, as in function
tc_new_tfilter.
When packets are enqueued through the root QFQ qdisc, the shared
leaf_qdisc->q.qlen increases. At the same time, the second QFQ
qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters
qfq_reset() with its own q->q.qlen == 0, but its class's leaf
qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate
an inactive aggregate and trigger a null-deref in qfq_deactivate_agg:
[ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 0.903571] #PF: supervisor write access in kernel mode
[ 0.903860] #PF: error_code(0x0002) - not-present page
[ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0
[ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI
[ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE
[ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014
[ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0
Code starting with the faulting instruction
===========================================
0: 0f 84 4d 01 00 00 je 0x153
6: 48 89 70 18 mov %rsi,0x18(%rax)
a: 8b 4b 10 mov 0x10(%rbx),%ecx
d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx
14: 48 8b 78 08 mov 0x8(%rax),%rdi
18: 48 d3 e2 shl %cl,%rdx
1b: 48 21 f2 and %rsi,%rdx
1e: 48 2b 13 sub (%rbx),%rdx
21: 48 8b 30 mov (%rax),%rsi
24: 48 d3 ea shr %cl,%rdx
27: 8b 4b 18 mov 0x18(%rbx),%ecx
...
[ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[ 0.910247] PKRU: 55555554
[ 0.910391] Call Trace:
[ 0.910527] <TASK>
[ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485)
[ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036)
[ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076)
[ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447)
[ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958)
[ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861)
[ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550)
[ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344)
[ 0.912296] ? __alloc_skb (net/core/skbuff.c:706)
[ 0.912484] netlink_sendmsg (net/netlink/af_netlink.c:1894)
[ 0.912682] sock_write_iter (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1) net/socket.c:1195 (discriminator 1))
[ 0.912880] vfs_write (fs/read_write.c:593 fs/read_write.c:686)
[ 0.913077] ksys_write (fs/read_write.c:738)
[ 0.913252] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1))
[ 0.913438] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131)
[ 0.913687] RIP: 0033:0x424c34
[ 0.913844] Code: 89 02 48 c7 c0 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d 2d 44 09 00 00 74 13 b8 01 00 00 00 0f 05 9
Code starting with the faulting instruction
===========================================
0: 89 02 mov %eax,(%rdx)
2: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax
9: eb bd jmp 0xffffffffffffffc8
b: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1)
12: 00 00 00
15: 90 nop
16: f3 0f 1e fa endbr64
1a: 80 3d 2d 44 09 00 00 cmpb $0x0,0x9442d(%rip) # 0x9444e
21: 74 13 je 0x36
23: b8 01 00 00 00 mov $0x1,%eax
28: 0f 05 syscall
2a: 09 .byte 0x9
[ 0.914807] RSP: 002b:00007ffea1938b78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
[ 0.915197] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000424c34
[ 0.915556] RDX: 000000000000003c RSI: 000000002af378c0 RDI: 0000000000000003
[ 0.915912] RBP: 00007ffea1938bc0 R08: 00000000004b8820 R09: 0000000000000000
[ 0.916297] R10: 0000000000000001 R11: 0000000000000202 R12: 00007ffea1938d28
[ 0.916652] R13: 00007ffea1938d38 R14: 00000000004b3828 R15: 0000000000000001
[ 0.917039] </TASK>
[ 0.917158] Modules linked in:
[ 0.917316] CR2: 0000000000000000
[ 0.917484] ---[ end trace 0000000000000000 ]---
[ 0.917717] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2))
[ 0.917978] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0
Code starting with the faulting instruction
===========================================
0: 0f 84 4d 01 00 00 je 0x153
6: 48 89 70 18 mov %rsi,0x18(%rax)
a: 8b 4b 10 mov 0x10(%rbx),%ecx
d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx
14: 48 8b 78 08 mov 0x8(%rax),%rdi
18: 48 d3 e2 shl %cl,%rdx
1b: 48 21 f2 and %rsi,%rdx
1e: 48 2b 13 sub (%rbx),%rdx
21: 48 8b 30 mov (%rax),%rsi
24: 48 d3 ea shr %cl,%rdx
27: 8b 4b 18 mov 0x18(%rbx),%ecx
...
[ 0.918902] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246
[ 0.919198] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000
[ 0.919559] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[ 0.919908] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000
[ 0.920289] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000
[ 0.920648] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880
[ 0.921014] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000
[ 0.921424] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 0.921710] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0
[ 0.922097] PKRU: 55555554
[ 0.922240] Kernel panic - not syncing: Fatal exception
[ 0.922590] Kernel Offset: disabled
Fixes: 0545a3037773 ("pkt_sched: QFQ - quick fair queue scheduler")
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Link: https://patch.msgid.link/20260106034100.1780779-1-xmei5@asu.edu
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit b1e125ae425aba9b45252e933ca8df52a843ec70 ]
Whenever a user issues an ets qdisc change command, transforming a
drr class into a strict one, the ets code isn't checking whether that
class was in the active list and removing it. This means that, if a
user changes a strict class (which was in the active list) back to a drr
one, that class will be added twice to the active list [1].
Doing so with the following commands:
tc qdisc add dev lo root handle 1: ets bands 2 strict 1
tc qdisc add dev lo parent 1:2 handle 20: \
tbf rate 8bit burst 100b latency 1s
tc filter add dev lo parent 1: basic classid 1:2
ping -c1 -W0.01 -s 56 127.0.0.1
tc qdisc change dev lo root handle 1: ets bands 2 strict 2
tc qdisc change dev lo root handle 1: ets bands 2 strict 1
ping -c1 -W0.01 -s 56 127.0.0.1
Will trigger the following splat with list debug turned on:
[ 59.279014][ T365] ------------[ cut here ]------------
[ 59.279452][ T365] list_add double add: new=ffff88801d60e350, prev=ffff88801d60e350, next=ffff88801d60e2c0.
[ 59.280153][ T365] WARNING: CPU: 3 PID: 365 at lib/list_debug.c:35 __list_add_valid_or_report+0x17f/0x220
[ 59.280860][ T365] Modules linked in:
[ 59.281165][ T365] CPU: 3 UID: 0 PID: 365 Comm: tc Not tainted 6.18.0-rc7-00105-g7e9f13163c13-dirty #239 PREEMPT(voluntary)
[ 59.281977][ T365] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 59.282391][ T365] RIP: 0010:__list_add_valid_or_report+0x17f/0x220
[ 59.282842][ T365] Code: 89 c6 e8 d4 b7 0d ff 90 0f 0b 90 90 31 c0 e9 31 ff ff ff 90 48 c7 c7 e0 a0 22 9f 48 89 f2 48 89 c1 4c 89 c6 e8 b2 b7 0d ff 90 <0f> 0b 90 90 31 c0 e9 0f ff ff ff 48 89 f7 48 89 44 24 10 4c 89 44
...
[ 59.288812][ T365] Call Trace:
[ 59.289056][ T365] <TASK>
[ 59.289224][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.289546][ T365] ets_qdisc_change+0xd2b/0x1e80
[ 59.289891][ T365] ? __lock_acquire+0x7e7/0x1be0
[ 59.290223][ T365] ? __pfx_ets_qdisc_change+0x10/0x10
[ 59.290546][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.290898][ T365] ? __mutex_trylock_common+0xda/0x240
[ 59.291228][ T365] ? __pfx___mutex_trylock_common+0x10/0x10
[ 59.291655][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.291993][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.292313][ T365] ? trace_contention_end+0xc8/0x110
[ 59.292656][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.293022][ T365] ? srso_alias_return_thunk+0x5/0xfbef5
[ 59.293351][ T365] tc_modify_qdisc+0x63a/0x1cf0
Fix this by always checking and removing an ets class from the active list
when changing it to strict.
[1] https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/tree/net/sched/sch_ets.c?id=ce052b9402e461a9aded599f5b47e76bc727f7de#n663
Fixes: cd9b50adc6bb9 ("net/sched: ets: fix crash when flipping from 'strict' to 'quantum'")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20251208190125.1868423-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
ets_qdisc_change
[ Upstream commit ce052b9402e461a9aded599f5b47e76bc727f7de ]
zdi-disclosures@trendmicro.com says:
The vulnerability is a race condition between `ets_qdisc_dequeue` and
`ets_qdisc_change`. It leads to UAF on `struct Qdisc` object.
Attacker requires the capability to create new user and network namespace
in order to trigger the bug.
See my additional commentary at the end of the analysis.
Analysis:
static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
...
// (1) this lock is preventing .change handler (`ets_qdisc_change`)
//to race with .dequeue handler (`ets_qdisc_dequeue`)
sch_tree_lock(sch);
for (i = nbands; i < oldbands; i++) {
if (i >= q->nstrict && q->classes[i].qdisc->q.qlen)
list_del_init(&q->classes[i].alist);
qdisc_purge_queue(q->classes[i].qdisc);
}
WRITE_ONCE(q->nbands, nbands);
for (i = nstrict; i < q->nstrict; i++) {
if (q->classes[i].qdisc->q.qlen) {
// (2) the class is added to the q->active
list_add_tail(&q->classes[i].alist, &q->active);
q->classes[i].deficit = quanta[i];
}
}
WRITE_ONCE(q->nstrict, nstrict);
memcpy(q->prio2band, priomap, sizeof(priomap));
for (i = 0; i < q->nbands; i++)
WRITE_ONCE(q->classes[i].quantum, quanta[i]);
for (i = oldbands; i < q->nbands; i++) {
q->classes[i].qdisc = queues[i];
if (q->classes[i].qdisc != &noop_qdisc)
qdisc_hash_add(q->classes[i].qdisc, true);
}
// (3) the qdisc is unlocked, now dequeue can be called in parallel
// to the rest of .change handler
sch_tree_unlock(sch);
ets_offload_change(sch);
for (i = q->nbands; i < oldbands; i++) {
// (4) we're reducing the refcount for our class's qdisc and
// freeing it
qdisc_put(q->classes[i].qdisc);
// (5) If we call .dequeue between (4) and (5), we will have
// a strong UAF and we can control RIP
q->classes[i].qdisc = NULL;
WRITE_ONCE(q->classes[i].quantum, 0);
q->classes[i].deficit = 0;
gnet_stats_basic_sync_init(&q->classes[i].bstats);
memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
}
return 0;
}
Comment:
This happens because some of the classes have their qdiscs assigned to
NULL, but remain in the active list. This commit fixes this issue by always
removing the class from the active list before deleting and freeing its
associated qdisc
Reproducer Steps
(trimmed version of what was sent by zdi-disclosures@trendmicro.com)
```
DEV="${DEV:-lo}"
ROOT_HANDLE="${ROOT_HANDLE:-1:}"
BAND2_HANDLE="${BAND2_HANDLE:-20:}" # child under 1:2
PING_BYTES="${PING_BYTES:-48}"
PING_COUNT="${PING_COUNT:-200000}"
PING_DST="${PING_DST:-127.0.0.1}"
SLOW_TBF_RATE="${SLOW_TBF_RATE:-8bit}"
SLOW_TBF_BURST="${SLOW_TBF_BURST:-100b}"
SLOW_TBF_LAT="${SLOW_TBF_LAT:-1s}"
cleanup() {
tc qdisc del dev "$DEV" root 2>/dev/null
}
trap cleanup EXIT
ip link set "$DEV" up
tc qdisc del dev "$DEV" root 2>/dev/null || true
tc qdisc add dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc qdisc add dev "$DEV" parent 1:2 handle "$BAND2_HANDLE" \
tbf rate "$SLOW_TBF_RATE" burst "$SLOW_TBF_BURST" latency "$SLOW_TBF_LAT"
tc filter add dev "$DEV" parent 1: protocol all prio 1 u32 match u32 0 0 flowid 1:2
tc -s qdisc ls dev $DEV
ping -I "$DEV" -f -c "$PING_COUNT" -s "$PING_BYTES" -W 0.001 "$PING_DST" \
>/dev/null 2>&1 &
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 0
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc -s qdisc ls dev $DEV
tc qdisc del dev "$DEV" parent 1:2 || true
tc -s qdisc ls dev $DEV
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 1 strict 1
```
KASAN report
```
==================================================================
BUG: KASAN: slab-use-after-free in ets_qdisc_dequeue+0x1071/0x11b0 kernel/net/sched/sch_ets.c:481
Read of size 8 at addr ffff8880502fc018 by task ping/12308
>
CPU: 0 UID: 0 PID: 12308 Comm: ping Not tainted 6.18.0-rc4-dirty #1 PREEMPT(full)
Hardware name: QEMU Ubuntu 25.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<IRQ>
__dump_stack kernel/lib/dump_stack.c:94
dump_stack_lvl+0x100/0x190 kernel/lib/dump_stack.c:120
print_address_description kernel/mm/kasan/report.c:378
print_report+0x156/0x4c9 kernel/mm/kasan/report.c:482
kasan_report+0xdf/0x110 kernel/mm/kasan/report.c:595
ets_qdisc_dequeue+0x1071/0x11b0 kernel/net/sched/sch_ets.c:481
dequeue_skb kernel/net/sched/sch_generic.c:294
qdisc_restart kernel/net/sched/sch_generic.c:399
__qdisc_run+0x1c9/0x1b00 kernel/net/sched/sch_generic.c:417
__dev_xmit_skb kernel/net/core/dev.c:4221
__dev_queue_xmit+0x2848/0x4410 kernel/net/core/dev.c:4729
dev_queue_xmit kernel/./include/linux/netdevice.h:3365
[...]
Allocated by task 17115:
kasan_save_stack+0x30/0x50 kernel/mm/kasan/common.c:56
kasan_save_track+0x14/0x30 kernel/mm/kasan/common.c:77
poison_kmalloc_redzone kernel/mm/kasan/common.c:400
__kasan_kmalloc+0xaa/0xb0 kernel/mm/kasan/common.c:417
kasan_kmalloc kernel/./include/linux/kasan.h:262
__do_kmalloc_node kernel/mm/slub.c:5642
__kmalloc_node_noprof+0x34e/0x990 kernel/mm/slub.c:5648
kmalloc_node_noprof kernel/./include/linux/slab.h:987
qdisc_alloc+0xb8/0xc30 kernel/net/sched/sch_generic.c:950
qdisc_create_dflt+0x93/0x490 kernel/net/sched/sch_generic.c:1012
ets_class_graft+0x4fd/0x800 kernel/net/sched/sch_ets.c:261
qdisc_graft+0x3e4/0x1780 kernel/net/sched/sch_api.c:1196
[...]
Freed by task 9905:
kasan_save_stack+0x30/0x50 kernel/mm/kasan/common.c:56
kasan_save_track+0x14/0x30 kernel/mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x70 kernel/mm/kasan/generic.c:587
kasan_save_free_info kernel/mm/kasan/kasan.h:406
poison_slab_object kernel/mm/kasan/common.c:252
__kasan_slab_free+0x5f/0x80 kernel/mm/kasan/common.c:284
kasan_slab_free kernel/./include/linux/kasan.h:234
slab_free_hook kernel/mm/slub.c:2539
slab_free kernel/mm/slub.c:6630
kfree+0x144/0x700 kernel/mm/slub.c:6837
rcu_do_batch kernel/kernel/rcu/tree.c:2605
rcu_core+0x7c0/0x1500 kernel/kernel/rcu/tree.c:2861
handle_softirqs+0x1ea/0x8a0 kernel/kernel/softirq.c:622
__do_softirq kernel/kernel/softirq.c:656
[...]
Commentary:
1. Maher Azzouzi working with Trend Micro Zero Day Initiative was reported as
the person who found the issue. I requested to get a proper email to add to the
reported-by tag but got no response. For this reason i will credit the person
i exchanged emails with i.e zdi-disclosures@trendmicro.com
2. Neither i nor Victor who did a much more thorough testing was able to
reproduce a UAF with the PoC or other approaches we tried. We were both able to
reproduce a null ptr deref. After exchange with zdi-disclosures@trendmicro.com
they sent a small change to be made to the code to add an extra delay which
was able to simulate the UAF. i.e, this:
qdisc_put(q->classes[i].qdisc);
mdelay(90);
q->classes[i].qdisc = NULL;
I was informed by Thomas Gleixner(tglx@linutronix.de) that adding delays was
acceptable approach for demonstrating the bug, quote:
"Adding such delays is common exploit validation practice"
The equivalent delay could happen "by virt scheduling the vCPU out, SMIs,
NMIs, PREEMPT_RT enabled kernel"
3. I asked the OP to test and report back but got no response and after a
few days gave up and proceeded to submit this fix.
Fixes: de6d25924c2a ("net/sched: sch_ets: don't peek at classes beyond 'nbands'")
Reported-by: zdi-disclosures@trendmicro.com
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20251128151919.576920-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 9fefc78f7f02d71810776fdeb119a05a946a27cc ]
In cake_drop(), qdisc_tree_reduce_backlog() is used to update the qlen
and backlog of the qdisc hierarchy. Its caller, cake_enqueue(), assumes
that the parent qdisc will enqueue the current packet. However, this
assumption breaks when cake_enqueue() returns NET_XMIT_CN: the parent
qdisc stops enqueuing current packet, leaving the tree qlen/backlog
accounting inconsistent. This mismatch can lead to a NULL dereference
(e.g., when the parent Qdisc is qfq_qdisc).
This patch computes the qlen/backlog delta in a more robust way by
observing the difference before and after the series of cake_drop()
calls, and then compensates the qdisc tree accounting if cake_enqueue()
returns NET_XMIT_CN.
To ensure correct compensation when ACK thinning is enabled, a new
variable is introduced to keep qlen unchanged.
Fixes: 15de71d06a40 ("net/sched: Make cake_enqueue return NET_XMIT_CN when past buffer_limit")
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Toke Høiland-Jørgensen <toke@toke.dk>
Link: https://patch.msgid.link/20251128001415.377823-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 4ef92743625818932b9c320152b58274c05e5053 ]
syzbot found that cls_bpf_classify() is able to change
tc_skb_cb(skb)->drop_reason triggering a warning in sk_skb_reason_drop().
WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 __sk_skb_reason_drop net/core/skbuff.c:1189 [inline]
WARNING: CPU: 0 PID: 5965 at net/core/skbuff.c:1192 sk_skb_reason_drop+0x76/0x170 net/core/skbuff.c:1214
struct tc_skb_cb has been added in commit ec624fe740b4 ("net/sched:
Extend qdisc control block with tc control block"), which added a wrong
interaction with db58ba459202 ("bpf: wire in data and data_end for
cls_act_bpf").
drop_reason was added later.
Add bpf_prog_run_data_pointers() helper to save/restore the net_sched
storage colliding with BPF data_meta/data_end.
Fixes: ec624fe740b4 ("net/sched: Extend qdisc control block with tc control block")
Reported-by: syzbot <syzkaller@googlegroups.com>
Closes: https://lore.kernel.org/netdev/6913437c.a70a0220.22f260.013b.GAE@google.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Victor Nogueira <victor@mojatatu.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251112125516.1563021-1-edumazet@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
|
|
[ Upstream commit 0345552a653ce5542affeb69ac5aa52177a5199b ]
After commit 100dfa74cad9 ("inet: dev_queue_xmit() llist adoption")
I started seeing many qdisc requeues on IDPF under high TX workload.
$ tc -s qd sh dev eth1 handle 1: ; sleep 1; tc -s qd sh dev eth1 handle 1:
qdisc mq 1: root
Sent 43534617319319 bytes 268186451819 pkt (dropped 0, overlimits 0 requeues 3532840114)
backlog 1056Kb 6675p requeues 3532840114
qdisc mq 1: root
Sent 43554665866695 bytes 268309964788 pkt (dropped 0, overlimits 0 requeues 3537737653)
backlog 781164b 4822p requeues 3537737653
This is caused by try_bulk_dequeue_skb() being only limited by BQL budget.
perf record -C120-239 -e qdisc:qdisc_dequeue sleep 1 ; perf script
...
netperf 75332 [146] 2711.138269: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1292 skbaddr=0xff378005a1e9f200
netperf 75332 [146] 2711.138953: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1213 skbaddr=0xff378004d607a500
netperf 75330 [144] 2711.139631: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1233 skbaddr=0xff3780046be20100
netperf 75333 [147] 2711.140356: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1093 skbaddr=0xff37800514845b00
netperf 75337 [151] 2711.141037: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1353 skbaddr=0xff37800460753300
netperf 75337 [151] 2711.141877: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1367 skbaddr=0xff378004e72c7b00
netperf 75330 [144] 2711.142643: qdisc:qdisc_dequeue: dequeue ifindex=5 qdisc handle=0x80150000 parent=0x10013 txq_state=0x0 packets=1202 skbaddr=0xff3780045bd60000
...
This is bad because :
1) Large batches hold one victim cpu for a very long time.
2) Driver often hit their own TX ring limit (all slots are used).
3) We call dev_requeue_skb()
4) Requeues are using a FIFO (q->gso_skb), breaking qdisc ability to
implement FQ or priority scheduling.
5) dequeue_skb() gets packets from q->gso_skb one skb at a time
with no xmit_more support. This is causing many spinlock games
between the qdisc and the device driver.
Requeues were supposed to be very rare, lets keep them this way.
Limit batch sizes to /proc/sys/net/core/dev_weight (default 64) as
__qdisc_run() was designed to use.
Fixes: 5772e9a3463b ("qdisc: bulk dequeue support for qdiscs with TCQ_F_ONETXQUEUE")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://patch.msgid.link/20251109161215.2574081-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ce50039be49eea9b4cd8873ca6eccded1b4a130a ]
Fix a KMSAN kernel-infoleak detected by the syzbot .
[net?] KMSAN: kernel-infoleak in __skb_datagram_iter
In tcf_ife_dump(), the variable 'opt' was partially initialized using a
designatied initializer. While the padding bytes are reamined
uninitialized. nla_put() copies the entire structure into a
netlink message, these uninitialized bytes leaked to userspace.
Initialize the structure with memset before assigning its fields
to ensure all members and padding are cleared prior to beign copied.
This change silences the KMSAN report and prevents potential information
leaks from the kernel memory.
This fix has been tested and validated by syzbot. This patch closes the
bug reported at the following syzkaller link and ensures no infoleak.
Reported-by: syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0c85cae3350b7d486aee
Tested-by: syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com
Fixes: ef6980b6becb ("introduce IFE action")
Signed-off-by: Ranganath V N <vnranganath.20@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251109091336.9277-3-vnranganath.20@gmail.com
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 62b656e43eaeae445a39cd8021a4f47065af4389 ]
In tcf_connmark_dump(), the variable 'opt' was partially initialized using a
designatied initializer. While the padding bytes are reamined
uninitialized. nla_put() copies the entire structure into a
netlink message, these uninitialized bytes leaked to userspace.
Initialize the structure with memset before assigning its fields
to ensure all members and padding are cleared prior to beign copied.
Reported-by: syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0c85cae3350b7d486aee
Tested-by: syzbot+0c85cae3350b7d486aee@syzkaller.appspotmail.com
Fixes: 22a5dc0e5e3e ("net: sched: Introduce connmark action")
Signed-off-by: Ranganath V N <vnranganath.20@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20251109091336.9277-2-vnranganath.20@gmail.com
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0d752877705c0252ef2726e4c63c5573f048951c ]
Also storing tcf_action into struct tcf_connmark_parms
makes sure there is no discrepancy in tcf_connmark_act().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250709090204.797558-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 62b656e43eae ("net: sched: act_connmark: initialize struct tc_ife to fix kernel leak")
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit dd831ac8221e691e9e918585b1003c7071df0379 upstream.
To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c)
when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return
value before using it, similar to the existing approach in sch_hfsc.c.
To avoid code duplication, the following changes are made:
1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static
inline function.
2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to
include/net/pkt_sched.h so that sch_qfq can reuse it.
3. Applied qdisc_peek_len in agg_dequeue to avoid crashing.
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://patch.msgid.link/20250705212143.3982664-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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htb_activate
[ Upstream commit 2c2192e5f9c7c2892fe2363244d1387f62710d83 ]
The WARN_ON trigger based on !cl->leaf.q->q.qlen is unnecessary in
htb_activate. htb_dequeue_tree already accounts for that scenario.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: William Liu <will@willsroot.io>
Reviewed-by: Savino Dicanosa <savy@syst3mfailure.io>
Link: https://patch.msgid.link/20250819033632.579854-1-will@willsroot.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 15de71d06a400f7fdc15bf377a2552b0ec437cf5 ]
The following setup can trigger a WARNING in htb_activate due to
the condition: !cl->leaf.q->q.qlen
tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: htb default 1
tc class add dev lo parent 1: classid 1:1 \
htb rate 64bit
tc qdisc add dev lo parent 1:1 handle f: \
cake memlimit 1b
ping -I lo -f -c1 -s64 -W0.001 127.0.0.1
This is because the low memlimit leads to a low buffer_limit, which
causes packet dropping. However, cake_enqueue still returns
NET_XMIT_SUCCESS, causing htb_enqueue to call htb_activate with an
empty child qdisc. We should return NET_XMIT_CN when packets are
dropped from the same tin and flow.
I do not believe return value of NET_XMIT_CN is necessary for packet
drops in the case of ack filtering, as that is meant to optimize
performance, not to signal congestion.
Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc")
Signed-off-by: William Liu <will@willsroot.io>
Reviewed-by: Savino Dicanosa <savy@syst3mfailure.io>
Acked-by: Toke Høiland-Jørgensen <toke@toke.dk>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250819033601.579821-1-will@willsroot.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 87c6efc5ce9c126ae4a781bc04504b83780e3650 upstream.
Shuang reported sch_ets test-case [1] crashing in ets_class_qlen_notify()
after recent changes from Lion [2]. The problem is: in ets_qdisc_change()
we purge unused DWRR queues; the value of 'q->nbands' is the new one, and
the cleanup should be done with the old one. The problem is here since my
first attempts to fix ets_qdisc_change(), but it surfaced again after the
recent qdisc len accounting fixes. Fix it purging idle DWRR queues before
assigning a new value of 'q->nbands', so that all purge operations find a
consistent configuration:
- old 'q->nbands' because it's needed by ets_class_find()
- old 'q->nstrict' because it's needed by ets_class_is_strict()
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: Oops: 0000 [#1] SMP NOPTI
CPU: 62 UID: 0 PID: 39457 Comm: tc Kdump: loaded Not tainted 6.12.0-116.el10.x86_64 #1 PREEMPT(voluntary)
Hardware name: Dell Inc. PowerEdge R640/06DKY5, BIOS 2.12.2 07/09/2021
RIP: 0010:__list_del_entry_valid_or_report+0x4/0x80
Code: ff 4c 39 c7 0f 84 39 19 8e ff b8 01 00 00 00 c3 cc cc cc cc 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa <48> 8b 17 48 8b 4f 08 48 85 d2 0f 84 56 19 8e ff 48 85 c9 0f 84 ab
RSP: 0018:ffffba186009f400 EFLAGS: 00010202
RAX: 00000000000000d6 RBX: 0000000000000000 RCX: 0000000000000004
RDX: ffff9f0fa29b69c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffffffc12c2400 R08: 0000000000000008 R09: 0000000000000004
R10: ffffffffffffffff R11: 0000000000000004 R12: 0000000000000000
R13: ffff9f0f8cfe0000 R14: 0000000000100005 R15: 0000000000000000
FS: 00007f2154f37480(0000) GS:ffff9f269c1c0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000001530be001 CR4: 00000000007726f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
<TASK>
ets_class_qlen_notify+0x65/0x90 [sch_ets]
qdisc_tree_reduce_backlog+0x74/0x110
ets_qdisc_change+0x630/0xa40 [sch_ets]
__tc_modify_qdisc.constprop.0+0x216/0x7f0
tc_modify_qdisc+0x7c/0x120
rtnetlink_rcv_msg+0x145/0x3f0
netlink_rcv_skb+0x53/0x100
netlink_unicast+0x245/0x390
netlink_sendmsg+0x21b/0x470
____sys_sendmsg+0x39d/0x3d0
___sys_sendmsg+0x9a/0xe0
__sys_sendmsg+0x7a/0xd0
do_syscall_64+0x7d/0x160
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f2155114084
Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d 25 f0 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
RSP: 002b:00007fff1fd7a988 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000560ec063e5e0 RCX: 00007f2155114084
RDX: 0000000000000000 RSI: 00007fff1fd7a9f0 RDI: 0000000000000003
RBP: 00007fff1fd7aa60 R08: 0000000000000010 R09: 000000000000003f
R10: 0000560ee9b3a010 R11: 0000000000000202 R12: 00007fff1fd7aae0
R13: 000000006891ccde R14: 0000560ec063e5e0 R15: 00007fff1fd7aad0
</TASK>
[1] https://lore.kernel.org/netdev/e08c7f4a6882f260011909a868311c6e9b54f3e4.1639153474.git.dcaratti@redhat.com/
[2] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/
Cc: stable@vger.kernel.org
Fixes: 103406b38c60 ("net/sched: Always pass notifications when child class becomes empty")
Fixes: c062f2a0b04d ("net/sched: sch_ets: don't remove idle classes from the round-robin list")
Fixes: dcc68b4d8084 ("net: sch_ets: Add a new Qdisc")
Reported-by: Li Shuang <shuali@redhat.com>
Closes: https://issues.redhat.com/browse/RHEL-108026
Reviewed-by: Petr Machata <petrm@nvidia.com>
Co-developed-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/7928ff6d17db47a2ae7cc205c44777b1f1950545.1755016081.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit ffd2dc4c6c49ff4f1e5d34e454a6a55608104c17 ]
TCA_MQPRIO_TC_ENTRY_INDEX is validated using
NLA_POLICY_MAX(NLA_U32, TC_QOPT_MAX_QUEUE), which allows the value
TC_QOPT_MAX_QUEUE (16). This leads to a 4-byte out-of-bounds stack
write in the fp[] array, which only has room for 16 elements (0–15).
Fix this by changing the policy to allow only up to TC_QOPT_MAX_QUEUE - 1.
Fixes: f62af20bed2d ("net/sched: mqprio: allow per-TC user input of FP adminStatus")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maher Azzouzi <maherazz04@gmail.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://patch.msgid.link/20250802001857.2702497-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ae8508b25def57982493c48694ef135973bfabe0 ]
Syzbot reported a WARNING in taprio_get_start_time().
When link speed is 470,589 or greater, q->picos_per_byte becomes too
small, causing length_to_duration(q, ETH_ZLEN) to return zero.
This zero value leads to validation failures in fill_sched_entry() and
parse_taprio_schedule(), allowing arbitrary values to be assigned to
entry->interval and cycle_time. As a result, sched->cycle can become zero.
Since SPEED_800000 is the largest defined speed in
include/uapi/linux/ethtool.h, this issue can occur in realistic scenarios.
To ensure length_to_duration() returns a non-zero value for minimum-sized
Ethernet frames (ETH_ZLEN = 60), picos_per_byte must be at least 17
(60 * 17 > PSEC_PER_NSEC which is 1000).
This patch enforces a minimum value of 17 for picos_per_byte when the
calculated value would be lower, and adds a warning message to inform
users that scheduling accuracy may be affected at very high link speeds.
Fixes: fb66df20a720 ("net/sched: taprio: extend minimum interval restriction to entire cycle too")
Reported-by: syzbot+398e1ee4ca2cac05fddb@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=398e1ee4ca2cac05fddb
Signed-off-by: Takamitsu Iwai <takamitz@amazon.co.jp>
Link: https://patch.msgid.link/20250728173149.45585-1-takamitz@amazon.co.jp
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d300335b4e18672913dd792ff9f49e6cccf41d26 ]
Commit 21c167aa0ba9 ("net/sched: act_ctinfo: use percpu stats")
missed that stats_dscp_set, stats_dscp_error and stats_cpmark_set
might be written (and read) locklessly.
Use atomic64_t for these three fields, I doubt act_ctinfo is used
heavily on big SMP hosts anyway.
Fixes: 24ec483cec98 ("net: sched: Introduce act_ctinfo action")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pedro Tammela <pctammela@mojatatu.com>
Link: https://patch.msgid.link/20250709090204.797558-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ec8e0e3d7adef940cdf9475e2352c0680189d14e ]
netem_enqueue's duplication prevention logic breaks when a netem
resides in a qdisc tree with other netems - this can lead to a
soft lockup and OOM loop in netem_dequeue, as seen in [1].
Ensure that a duplicating netem cannot exist in a tree with other
netems.
Previous approaches suggested in discussions in chronological order:
1) Track duplication status or ttl in the sk_buff struct. Considered
too specific a use case to extend such a struct, though this would
be a resilient fix and address other previous and potential future
DOS bugs like the one described in loopy fun [2].
2) Restrict netem_enqueue recursion depth like in act_mirred with a
per cpu variable. However, netem_dequeue can call enqueue on its
child, and the depth restriction could be bypassed if the child is a
netem.
3) Use the same approach as in 2, but add metadata in netem_skb_cb
to handle the netem_dequeue case and track a packet's involvement
in duplication. This is an overly complex approach, and Jamal
notes that the skb cb can be overwritten to circumvent this
safeguard.
4) Prevent the addition of a netem to a qdisc tree if its ancestral
path contains a netem. However, filters and actions can cause a
packet to change paths when re-enqueued to the root from netem
duplication, leading us to the current solution: prevent a
duplicating netem from inhabiting the same tree as other netems.
[1] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/
[2] https://lwn.net/Articles/719297/
Fixes: 0afb51e72855 ("[PKT_SCHED]: netem: reinsert for duplication")
Reported-by: William Liu <will@willsroot.io>
Reported-by: Savino Dicanosa <savy@syst3mfailure.io>
Signed-off-by: William Liu <will@willsroot.io>
Signed-off-by: Savino Dicanosa <savy@syst3mfailure.io>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20250708164141.875402-1-will@willsroot.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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qfq_delete_class
[ Upstream commit cf074eca0065bc5142e6004ae236bb35a2687fdf ]
might_sleep could be trigger in the atomic context in qfq_delete_class.
qfq_destroy_class was moved into atomic context locked
by sch_tree_lock to avoid a race condition bug on
qfq_aggregate. However, might_sleep could be triggered by
qfq_destroy_class, which introduced sleeping in atomic context (path:
qfq_destroy_class->qdisc_put->__qdisc_destroy->lockdep_unregister_key
->might_sleep).
Considering the race is on the qfq_aggregate objects, keeping
qfq_rm_from_agg in the lock but moving the left part out can solve
this issue.
Fixes: 5e28d5a3f774 ("net/sched: sch_qfq: Fix race condition on qfq_aggregate")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Link: https://patch.msgid.link/4a04e0cc-a64b-44e7-9213-2880ed641d77@sabinyo.mountain
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://patch.msgid.link/20250717230128.159766-1-xmei5@asu.edu
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 0e1d5d9b5c5966e2e42e298670808590db5ed628 ]
htb_lookup_leaf has a BUG_ON that can trigger with the following:
tc qdisc del dev lo root
tc qdisc add dev lo root handle 1: htb default 1
tc class add dev lo parent 1: classid 1:1 htb rate 64bit
tc qdisc add dev lo parent 1:1 handle 2: netem
tc qdisc add dev lo parent 2:1 handle 3: blackhole
ping -I lo -c1 -W0.001 127.0.0.1
The root cause is the following:
1. htb_dequeue calls htb_dequeue_tree which calls the dequeue handler on
the selected leaf qdisc
2. netem_dequeue calls enqueue on the child qdisc
3. blackhole_enqueue drops the packet and returns a value that is not
just NET_XMIT_SUCCESS
4. Because of this, netem_dequeue calls qdisc_tree_reduce_backlog, and
since qlen is now 0, it calls htb_qlen_notify -> htb_deactivate ->
htb_deactiviate_prios -> htb_remove_class_from_row -> htb_safe_rb_erase
5. As this is the only class in the selected hprio rbtree,
__rb_change_child in __rb_erase_augmented sets the rb_root pointer to
NULL
6. Because blackhole_dequeue returns NULL, netem_dequeue returns NULL,
which causes htb_dequeue_tree to call htb_lookup_leaf with the same
hprio rbtree, and fail the BUG_ON
The function graph for this scenario is shown here:
0) | htb_enqueue() {
0) + 13.635 us | netem_enqueue();
0) 4.719 us | htb_activate_prios();
0) # 2249.199 us | }
0) | htb_dequeue() {
0) 2.355 us | htb_lookup_leaf();
0) | netem_dequeue() {
0) + 11.061 us | blackhole_enqueue();
0) | qdisc_tree_reduce_backlog() {
0) | qdisc_lookup_rcu() {
0) 1.873 us | qdisc_match_from_root();
0) 6.292 us | }
0) 1.894 us | htb_search();
0) | htb_qlen_notify() {
0) 2.655 us | htb_deactivate_prios();
0) 6.933 us | }
0) + 25.227 us | }
0) 1.983 us | blackhole_dequeue();
0) + 86.553 us | }
0) # 2932.761 us | qdisc_warn_nonwc();
0) | htb_lookup_leaf() {
0) | BUG_ON();
------------------------------------------
The full original bug report can be seen here [1].
We can fix this just by returning NULL instead of the BUG_ON,
as htb_dequeue_tree returns NULL when htb_lookup_leaf returns
NULL.
[1] https://lore.kernel.org/netdev/pF5XOOIim0IuEfhI-SOxTgRvNoDwuux7UHKnE_Y5-zVd4wmGvNk2ceHjKb8ORnzw0cGwfmVu42g9dL7XyJLf1NEzaztboTWcm0Ogxuojoeo=@willsroot.io/
Fixes: 512bb43eb542 ("pkt_sched: sch_htb: Optimize WARN_ONs in htb_dequeue_tree() etc.")
Signed-off-by: William Liu <will@willsroot.io>
Signed-off-by: Savino Dicanosa <savy@syst3mfailure.io>
Link: https://patch.msgid.link/20250717022816.221364-1-will@willsroot.io
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 5e28d5a3f774f118896aec17a3a20a9c5c9dfc64 ]
A race condition can occur when 'agg' is modified in qfq_change_agg
(called during qfq_enqueue) while other threads access it
concurrently. For example, qfq_dump_class may trigger a NULL
dereference, and qfq_delete_class may cause a use-after-free.
This patch addresses the issue by:
1. Moved qfq_destroy_class into the critical section.
2. Added sch_tree_lock protection to qfq_dump_class and
qfq_dump_class_stats.
Fixes: 462dbc9101ac ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost")
Signed-off-by: Xiang Mei <xmei5@asu.edu>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ffdde7bf5a439aaa1955ebd581f5c64ab1533963 ]
Lion's patch [1] revealed an ancient bug in the qdisc API.
Whenever a user creates/modifies a qdisc specifying as a parent another
qdisc, the qdisc API will, during grafting, detect that the user is
not trying to attach to a class and reject. However grafting is
performed after qdisc_create (and thus the qdiscs' init callback) is
executed. In qdiscs that eventually call qdisc_tree_reduce_backlog
during init or change (such as fq, hhf, choke, etc), an issue
arises. For example, executing the following commands:
sudo tc qdisc add dev lo root handle a: htb default 2
sudo tc qdisc add dev lo parent a: handle beef fq
Qdiscs such as fq, hhf, choke, etc unconditionally invoke
qdisc_tree_reduce_backlog() in their control path init() or change() which
then causes a failure to find the child class; however, that does not stop
the unconditional invocation of the assumed child qdisc's qlen_notify with
a null class. All these qdiscs make the assumption that class is non-null.
The solution is ensure that qdisc_leaf() which looks up the parent
class, and is invoked prior to qdisc_create(), should return failure on
not finding the class.
In this patch, we leverage qdisc_leaf to return ERR_PTRs whenever the
parentid doesn't correspond to a class, so that we can detect it
earlier on and abort before qdisc_create is called.
[1] https://lore.kernel.org/netdev/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com/
Fixes: 5e50da01d0ce ("[NET_SCHED]: Fix endless loops (part 2): "simple" qdiscs")
Reported-by: syzbot+d8b58d7b0ad89a678a16@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68663c93.a70a0220.5d25f.0857.GAE@google.com/
Reported-by: syzbot+5eccb463fa89309d8bdc@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68663c94.a70a0220.5d25f.0858.GAE@google.com/
Reported-by: syzbot+1261670bbdefc5485a06@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0013.GAE@google.com/
Reported-by: syzbot+15b96fc3aac35468fe77@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/686764a5.a00a0220.c7b3.0014.GAE@google.com/
Reported-by: syzbot+4dadc5aecf80324d5a51@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/68679e81.a70a0220.29cf51.0016.GAE@google.com/
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250707210801.372995-1-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 103406b38c600fec1fe375a77b27d87e314aea09 ]
Certain classful qdiscs may invoke their classes' dequeue handler on an
enqueue operation. This may unexpectedly empty the child qdisc and thus
make an in-flight class passive via qlen_notify(). Most qdiscs do not
expect such behaviour at this point in time and may re-activate the
class eventually anyways which will lead to a use-after-free.
The referenced fix commit attempted to fix this behavior for the HFSC
case by moving the backlog accounting around, though this turned out to
be incomplete since the parent's parent may run into the issue too.
The following reproducer demonstrates this use-after-free:
tc qdisc add dev lo root handle 1: drr
tc filter add dev lo parent 1: basic classid 1:1
tc class add dev lo parent 1: classid 1:1 drr
tc qdisc add dev lo parent 1:1 handle 2: hfsc def 1
tc class add dev lo parent 2: classid 2:1 hfsc rt m1 8 d 1 m2 0
tc qdisc add dev lo parent 2:1 handle 3: netem
tc qdisc add dev lo parent 3:1 handle 4: blackhole
echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888
tc class delete dev lo classid 1:1
echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888
Since backlog accounting issues leading to a use-after-frees on stale
class pointers is a recurring pattern at this point, this patch takes
a different approach. Instead of trying to fix the accounting, the patch
ensures that qdisc_tree_reduce_backlog always calls qlen_notify when
the child qdisc is empty. This solves the problem because deletion of
qdiscs always involves a call to qdisc_reset() and / or
qdisc_purge_queue() which ultimately resets its qlen to 0 thus causing
the following qdisc_tree_reduce_backlog() to report to the parent. Note
that this may call qlen_notify on passive classes multiple times. This
is not a problem after the recent patch series that made all the
classful qdiscs qlen_notify() handlers idempotent.
Fixes: 3f981138109f ("sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()")
Signed-off-by: Lion Ackermann <nnamrec@gmail.com>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Acked-by: Cong Wang <xiyou.wangcong@gmail.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/d912cbd7-193b-4269-9857-525bee8bbb6a@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 7ca52541c05c832d32b112274f81a985101f9ba8 upstream.
Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch.
We want to make sure ctl->perturb_period * HZ will not overflow
and is positive.
Tested:
tc qd add dev lo root sfq perturb -10 # negative value : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period.
tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec
Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0)
backlog 0b 0p requeues 0
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20250611083501.1810459-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b160766e26d4e2e2d6fe2294e0b02f92baefcec5 upstream.
Since taprio’s taprio_dev_notifier() isn’t protected by an
RCU read-side critical section, a race with advance_sched()
can lead to a use-after-free.
Adding rcu_read_lock() inside taprio_dev_notifier() prevents this.
Fixes: fed87cc6718a ("net/sched: taprio: automatically calculate queueMaxSDU based on TC gate durations")
Cc: stable@vger.kernel.org
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/aEzIYYxt0is9upYG@v4bel-B760M-AORUS-ELITE-AX
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit d92adacdd8c2960be856e0b82acc5b7c5395fddb ]
Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
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| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 43eb466041216d25dedaef1c383ad7bd89929cbc ]
Gerrard Tai reported a race condition in TBF, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
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| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
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[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Zhengchao Shao <shaozhengchao@huawei.com>
Link: https://patch.msgid.link/20250611111515.1983366-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 85a3e0ede38450ea3053b8c45d28cf55208409b8 ]
Gerrard Tai reported a race condition in RED, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 0c8d13ac9607 ("net: sched: red: delay destroying child qdisc on replace")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d35acc1be3480505b5931f17e4ea9b7617fea4d3 ]
Gerrard Tai reported a race condition in PRIO, whenever SFQ perturb timer
fires at the wrong time.
The race is as follows:
CPU 0 CPU 1
[1]: lock root
[2]: qdisc_tree_flush_backlog()
[3]: unlock root
|
| [5]: lock root
| [6]: rehash
| [7]: qdisc_tree_reduce_backlog()
|
[4]: qdisc_put()
This can be abused to underflow a parent's qlen.
Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog()
should fix the race, because all packets will be purged from the qdisc
before releasing the lock.
Fixes: 7b8e0b6e6599 ("net: sched: prio: delay destroying child qdiscs on change")
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Suggested-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250611111515.1983366-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 82ffbe7776d0ac084031f114167712269bf3d832 ]
SFQ has an assumption of always being able to queue at least one packet.
However, after the blamed commit, sch->q.len can be inflated by packets
in sch->gso_skb, and an enqueue() on an empty SFQ qdisc can be followed
by an immediate drop.
Fix sfq_drop() to properly clear q->tail in this situation.
Tested:
ip netns add lb
ip link add dev to-lb type veth peer name in-lb netns lb
ethtool -K to-lb tso off # force qdisc to requeue gso_skb
ip netns exec lb ethtool -K in-lb gro on # enable NAPI
ip link set dev to-lb up
ip -netns lb link set dev in-lb up
ip addr add dev to-lb 192.168.20.1/24
ip -netns lb addr add dev in-lb 192.168.20.2/24
tc qdisc replace dev to-lb root sfq limit 100
ip netns exec lb netserver
netperf -H 192.168.20.2 -l 100 &
netperf -H 192.168.20.2 -l 100 &
netperf -H 192.168.20.2 -l 100 &
netperf -H 192.168.20.2 -l 100 &
Fixes: a53851e2c321 ("net: sched: explicit locking in gso_cpu fallback")
Reported-by: Marcus Wichelmann <marcus.wichelmann@hetzner-cloud.de>
Closes: https://lore.kernel.org/netdev/9da42688-bfaa-4364-8797-e9271f3bdaef@hetzner-cloud.de/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20250606165127.3629486-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit ac9fe7dd8e730a103ae4481147395cc73492d786 upstream.
Savino says:
"We are writing to report that this recent patch
(141d34391abbb315d68556b7c67ad97885407547) [1]
can be bypassed, and a UAF can still occur when HFSC is utilized with
NETEM.
The patch only checks the cl->cl_nactive field to determine whether
it is the first insertion or not [2], but this field is only
incremented by init_vf [3].
By using HFSC_RSC (which uses init_ed) [4], it is possible to bypass the
check and insert the class twice in the eltree.
Under normal conditions, this would lead to an infinite loop in
hfsc_dequeue for the reasons we already explained in this report [5].
However, if TBF is added as root qdisc and it is configured with a
very low rate,
it can be utilized to prevent packets from being dequeued.
This behavior can be exploited to perform subsequent insertions in the
HFSC eltree and cause a UAF."
To fix both the UAF and the infinite loop, with netem as an hfsc child,
check explicitly in hfsc_enqueue whether the class is already in the eltree
whenever the HFSC_RSC flag is set.
[1] https://web.git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=141d34391abbb315d68556b7c67ad97885407547
[2] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L1572
[3] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L677
[4] https://elixir.bootlin.com/linux/v6.15-rc5/source/net/sched/sch_hfsc.c#L1574
[5] https://lore.kernel.org/netdev/8DuRWwfqjoRDLDmBMlIfbrsZg9Gx50DHJc1ilxsEBNe2D6NMoigR_eIRIG0LOjMc3r10nUUZtArXx4oZBIdUfZQrwjcQhdinnMis_0G7VEk=@willsroot.io/T/#u
Fixes: 37d9cf1a3ce3 ("sched: Fix detection of empty queues in child qdiscs")
Reported-by: Savino Dicanosa <savy@syst3mfailure.io>
Reported-by: William Liu <will@willsroot.io>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Link: https://patch.msgid.link/20250522181448.1439717-2-pctammela@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 3f981138109f63232a5fb7165938d4c945cc1b9d ]
When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the
child qdisc's peek() operation before incrementing sch->q.qlen and
sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may
trigger an immediate dequeue and potential packet drop. In such cases,
qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog
have not yet been updated, leading to inconsistent queue accounting. This
can leave an empty HFSC class in the active list, causing further
consequences like use-after-free.
This patch fixes the bug by moving the increment of sch->q.qlen and
sch->qstats.backlog before the call to the child qdisc's peek() operation.
This ensures that queue length and backlog are always accurate when packet
drops or dequeues are triggered during the peek.
Fixes: 12d0ad3be9c3 ("net/sched/sch_hfsc.c: handle corner cases where head may change invalidating calculated deadline")
Reported-by: Mingi Cho <mincho@theori.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250518222038.58538-2-xiyou.wangcong@gmail.com
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 2d3cbfd6d54a2c39ce3244f33f85c595844bd7b8 ]
Previously, when reducing a qdisc's limit via the ->change() operation, only
the main skb queue was trimmed, potentially leaving packets in the gso_skb
list. This could result in NULL pointer dereference when we only check
sch->limit against sch->q.qlen.
This patch introduces a new helper, qdisc_dequeue_internal(), which ensures
both the gso_skb list and the main queue are properly flushed when trimming
excess packets. All relevant qdiscs (codel, fq, fq_codel, fq_pie, hhf, pie)
are updated to use this helper in their ->change() routines.
Fixes: 76e3cc126bb2 ("codel: Controlled Delay AQM")
Fixes: 4b549a2ef4be ("fq_codel: Fair Queue Codel AQM")
Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler")
Fixes: ec97ecf1ebe4 ("net: sched: add Flow Queue PIE packet scheduler")
Fixes: 10239edf86f1 ("net-qdisc-hhf: Heavy-Hitter Filter (HHF) qdisc")
Fixes: d4b36210c2e6 ("net: pkt_sched: PIE AQM scheme")
Reported-by: Will <willsroot@protonmail.com>
Reported-by: Savy <savy@syst3mfailure.io>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3769478610135e82b262640252d90f6efb05be71 ]
Alan reported a NULL pointer dereference in htb_next_rb_node()
after we made htb_qlen_notify() idempotent.
It turns out in the following case it introduced some regression:
htb_dequeue_tree():
|-> fq_codel_dequeue()
|-> qdisc_tree_reduce_backlog()
|-> htb_qlen_notify()
|-> htb_deactivate()
|-> htb_next_rb_node()
|-> htb_deactivate()
For htb_next_rb_node(), after calling the 1st htb_deactivate(), the
clprio[prio]->ptr could be already set to NULL, which means
htb_next_rb_node() is vulnerable here.
For htb_deactivate(), although we checked qlen before calling it, in
case of qlen==0 after qdisc_tree_reduce_backlog(), we may call it again
which triggers the warning inside.
To fix the issues here, we need to:
1) Make htb_deactivate() idempotent, that is, simply return if we
already call it before.
2) Make htb_next_rb_node() safe against ptr==NULL.
Many thanks to Alan for testing and for the reproducer.
Fixes: 5ba8b837b522 ("sch_htb: make htb_qlen_notify() idempotent")
Reported-by: Alan J. Wylie <alan@wylie.me.uk>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://patch.msgid.link/20250428232955.1740419-2-xiyou.wangcong@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit a7a15f39c682ac4268624da2abdb9114bdde96d5 upstream.
est_qlen_notify() deletes its class from its active list with
list_del() when qlen is 0, therefore, it is not idempotent and
not friendly to its callers, like fq_codel_dequeue().
Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers'
life. Also change other list_del()'s to list_del_init() just to be
extra safe.
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Link: https://patch.msgid.link/20250403211033.166059-6-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 55f9eca4bfe30a15d8656f915922e8c98b7f0728 upstream.
qfq_qlen_notify() always deletes its class from its active list
with list_del_init() _and_ calls qfq_deactivate_agg() when the whole list
becomes empty.
To make it idempotent, just skip everything when it is not in the active
list.
Also change other list_del()'s to list_del_init() just to be extra safe.
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-5-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 51eb3b65544c9efd6a1026889ee5fb5aa62da3bb upstream.
hfsc_qlen_notify() is not idempotent either and not friendly
to its callers, like fq_codel_dequeue(). Let's make it idempotent
to ease qdisc_tree_reduce_backlog() callers' life:
1. update_vf() decreases cl->cl_nactive, so we can check whether it is
non-zero before calling it.
2. eltree_remove() always removes RB node cl->el_node, but we can use
RB_EMPTY_NODE() + RB_CLEAR_NODE() to make it safe.
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-4-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit df008598b3a00be02a8051fde89ca0fbc416bd55 upstream.
drr_qlen_notify() always deletes the DRR class from its active list
with list_del(), therefore, it is not idempotent and not friendly
to its callers, like fq_codel_dequeue().
Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers'
life. Also change other list_del()'s to list_del_init() just to be
extra safe.
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-3-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 5ba8b837b522d7051ef81bacf3d95383ff8edce5 upstream.
htb_qlen_notify() always deactivates the HTB class and in fact could
trigger a warning if it is already deactivated. Therefore, it is not
idempotent and not friendly to its callers, like fq_codel_dequeue().
Let's make it idempotent to ease qdisc_tree_reduce_backlog() callers'
life.
Reported-by: Gerrard Tai <gerrard.tai@starlabs.sg>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250403211033.166059-2-xiyou.wangcong@gmail.com
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit f139f37dcdf34b67f5bf92bc8e0f7f6b3ac63aa4 ]
As described in Gerrard's report [1], there are use cases where a netem
child qdisc will make the parent qdisc's enqueue callback reentrant.
In the case of qfq, there won't be a UAF, but the code will add the same
classifier to the list twice, which will cause memory corruption.
This patch checks whether the class was already added to the agg->active
list (cl_is_active) before doing the addition to cater for the reentrant
case.
[1] https://lore.kernel.org/netdev/CAHcdcOm+03OD2j6R0=YHKqmy=VgJ8xEOKuP6c7mSgnp-TEJJbw@mail.gmail.com/
Fixes: 37d9cf1a3ce3 ("sched: Fix detection of empty queues in child qdiscs")
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Victor Nogueira <victor@mojatatu.com>
Link: https://patch.msgid.link/20250425220710.3964791-5-victor@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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