kernel/linux.git/net/sched, branch v5.10.257

net/sched: cls_flow: fix NULL pointer dereference on shared blocks

2026-04-18T08:31:10+00:00

[ Upstream commit 1a280dd4bd1d616a01d6ffe0de284c907b555504 ] flow_change() calls tcf_block_q() and dereferences q->handle to derive a default baseclass. Shared blocks leave block->q NULL, causing a NULL deref when a flow filter without a fully qualified baseclass is created on a shared block. Check tcf_block_shared() before accessing block->q and return -EINVAL for shared blocks. This avoids the null-deref shown below: ======================================================================= KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:flow_change (net/sched/cls_flow.c:508) Call Trace: tc_new_tfilter (net/sched/cls_api.c:2432) rtnetlink_rcv_msg (net/core/rtnetlink.c:6980) [...] ======================================================================= Fixes: 1abf272022cf ("net: sched: tcindex, fw, flow: use tcf_block_q helper to get struct Qdisc") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Acked-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260331050217.504278-2-xmei5@asu.edu Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net/sched: cls_fw: fix NULL pointer dereference on shared blocks

2026-04-18T08:31:10+00:00

[ Upstream commit faeea8bbf6e958bf3c00cb08263109661975987c ] The old-method path in fw_classify() calls tcf_block_q() and dereferences q->handle. Shared blocks leave block->q NULL, causing a NULL deref when an empty cls_fw filter is attached to a shared block and a packet with a nonzero major skb mark is classified. Reject the configuration in fw_change() when the old method (no TCA_OPTIONS) is used on a shared block, since fw_classify()'s old-method path needs block->q which is NULL for shared blocks. The fixed null-ptr-deref calling stack: KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f] RIP: 0010:fw_classify (net/sched/cls_fw.c:81) Call Trace: tcf_classify (./include/net/tc_wrapper.h:197 net/sched/cls_api.c:1764 net/sched/cls_api.c:1860) tc_run (net/core/dev.c:4401) __dev_queue_xmit (net/core/dev.c:4535 net/core/dev.c:4790) Fixes: 1abf272022cf ("net: sched: tcindex, fw, flow: use tcf_block_q helper to get struct Qdisc") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Acked-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260331050217.504278-1-xmei5@asu.edu Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: sched: cls_api: fix tc_chain_fill_node to initialize tcm_info to zero to prevent an info-leak

2026-04-18T08:31:09+00:00

[ Upstream commit e6e3eb5ee89ac4c163d46429391c889a1bb5e404 ] When building netlink messages, tc_chain_fill_node() never initializes the tcm_info field of struct tcmsg. Since the allocation is not zeroed, kernel heap memory is leaked to userspace through this 4-byte field. The fix simply zeroes tcm_info alongside the other fields that are already initialized. Fixes: 32a4f5ecd738 ("net: sched: introduce chain object to uapi") Signed-off-by: Yochai Eisenrich Acked-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260328211436.1010152-1-echelonh@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/sched: sch_hfsc: fix divide-by-zero in rtsc_min()

2026-04-18T08:31:08+00:00

[ Upstream commit 4576100b8cd03118267513cafacde164b498b322 ] m2sm() converts a u32 slope to a u64 scaled value. For large inputs (e.g. m1=4000000000), the result can reach 2^32. rtsc_min() stores the difference of two such u64 values in a u32 variable `dsm` and uses it as a divisor. When the difference is exactly 2^32 the truncation yields zero, causing a divide-by-zero oops in the concave-curve intersection path: Oops: divide error: 0000 RIP: 0010:rtsc_min (net/sched/sch_hfsc.c:601) Call Trace: init_ed (net/sched/sch_hfsc.c:629) hfsc_enqueue (net/sched/sch_hfsc.c:1569) [...] Widen `dsm` to u64 and replace do_div() with div64_u64() so the full difference is preserved. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Weiming Shi Signed-off-by: Xiang Mei Acked-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260326204310.1549327-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/sched: act_gate: snapshot parameters with RCU on replace

2026-04-18T08:30:59+00:00

[ Upstream commit 62413a9c3cb183afb9bb6e94dd68caf4e4145f4c ] The gate action can be replaced while the hrtimer callback or dump path is walking the schedule list. Convert the parameters to an RCU-protected snapshot and swap updates under tcf_lock, freeing the previous snapshot via call_rcu(). When REPLACE omits the entry list, preserve the existing schedule so the effective state is unchanged. Fixes: a51c328df310 ("net: qos: introduce a gate control flow action") Cc: stable@vger.kernel.org Signed-off-by: Paul Moses Tested-by: Vladimir Oltean Acked-by: Jamal Hadi Salim Reviewed-by: Victor Nogueira Link: https://patch.msgid.link/20260223150512.2251594-2-p@1g4.org Signed-off-by: Jakub Kicinski [ Different function signatures, hrtimer changes, context ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

net/sched: teql: fix NULL pointer dereference in iptunnel_xmit on TEQL slave xmit

2026-04-18T08:30:53+00:00

[ Upstream commit 0cc0c2e661af418bbf7074179ea5cfffc0a5c466 ] teql_master_xmit() calls netdev_start_xmit(skb, slave) to transmit through slave devices, but does not update skb->dev to the slave device beforehand. When a gretap tunnel is a TEQL slave, the transmit path reaches iptunnel_xmit() which saves dev = skb->dev (still pointing to teql0 master) and later calls iptunnel_xmit_stats(dev, pkt_len). This function does: get_cpu_ptr(dev->tstats) Since teql_master_setup() does not set dev->pcpu_stat_type to NETDEV_PCPU_STAT_TSTATS, the core network stack never allocates tstats for teql0, so dev->tstats is NULL. get_cpu_ptr(NULL) computes NULL + __per_cpu_offset[cpu], resulting in a page fault. BUG: unable to handle page fault for address: ffff8880e6659018 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 68bc067 P4D 68bc067 PUD 0 Oops: Oops: 0002 [#1] SMP KASAN PTI RIP: 0010:iptunnel_xmit (./include/net/ip_tunnels.h:664 net/ipv4/ip_tunnel_core.c:89) Call Trace: ip_tunnel_xmit (net/ipv4/ip_tunnel.c:847) __gre_xmit (net/ipv4/ip_gre.c:478) gre_tap_xmit (net/ipv4/ip_gre.c:779) teql_master_xmit (net/sched/sch_teql.c:319) dev_hard_start_xmit (net/core/dev.c:3887) sch_direct_xmit (net/sched/sch_generic.c:347) __dev_queue_xmit (net/core/dev.c:4802) neigh_direct_output (net/core/neighbour.c:1660) ip_finish_output2 (net/ipv4/ip_output.c:237) __ip_finish_output.part.0 (net/ipv4/ip_output.c:315) ip_mc_output (net/ipv4/ip_output.c:369) ip_send_skb (net/ipv4/ip_output.c:1508) udp_send_skb (net/ipv4/udp.c:1195) udp_sendmsg (net/ipv4/udp.c:1485) inet_sendmsg (net/ipv4/af_inet.c:859) __sys_sendto (net/socket.c:2206) Fix this by setting skb->dev = slave before calling netdev_start_xmit(), so that tunnel xmit functions see the correct slave device with properly allocated tstats. Fixes: 039f50629b7f ("ip_tunnel: Move stats update to iptunnel_xmit()") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Link: https://patch.msgid.link/20260304044216.3517851-3-bestswngs@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/sched: ets: fix divide by zero in the offload path

2026-04-18T08:30:51+00:00

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: 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 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 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 Reviewed-by: Jamal Hadi Salim Reviewed-by: Petr Machata Link: https://patch.msgid.link/28504887df314588c7255e9911769c36f751edee.1771964872.git.dcaratti@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/sched: act_ife: convert comma to semicolon

2026-02-06T15:40:11+00:00

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 Reviewed-by: Jamal Hadi Salim Link: https://patch.msgid.link/20251112072709.73755-1-nichen@iscas.ac.cn Signed-off-by: Jakub Kicinski Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

net/sched: act_ife: avoid possible NULL deref

2026-02-06T15:40:06+00:00

[ 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: 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 Cc: Yotam Gigi Reviewed-by: Jamal Hadi Salim Link: https://patch.msgid.link/20260121133724.3400020-1-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net/sched: qfq: Use cl_is_active to determine whether class is active in qfq_rm_from_ag

2026-02-06T15:40:04+00:00

[ 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 Link: https://patch.msgid.link/20260114160243.913069-3-jhs@mojatatu.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin