kernel/linux.git/include, branch v6.6.152

net/sched: act_gact, act_police: range check the fallback control action

2026-08-19T16:13:12+00:00

commit 883b56ae58fe657d8497806c7059646e9ba6dbd0 upstream. tcf_action_check_ctrlact() range checks the primary control action: if (!opcode) ret = action > TC_ACT_VALUE_MAX ? -EINVAL : 0; TC_ACT_VALUE_MAX is TC_ACT_TRAP, so kernel-internal verdicts above it cannot be set that way. But act_gact and act_police each carry a second, independent control action supplied by user space that never reaches that helper - TCA_GACT_PROB.paction and TCA_POLICE_RESULT. Both only reject TC_ACT_GOTO_CHAIN, so any other value is stored verbatim and returned verbatim from the action. In particular user space can store TC_ACT_CONSUMED, which is TC_ACT_VALUE_MAX + 1 and is deliberately not part of the UAPI value range. That verdict tells every caller the action took ownership of the skb, so nobody frees it: sch_handle_ingress(), sch_handle_egress() and tcf_qevent_handle() all deliberately skip the free for it. The result is one leaked sk_buff plus its data buffer per packet traversing the filter, unbounded, for all traffic on the chain including kernel-generated packets. Both are trivially deterministic. act_gact clamps tcfg_pval to >= 1, so with pval = 1 gact_determ() returns the fallback for every packet. act_police has no mandatory rate, so rate = 0 leaves tcfp_mtu = ~0 and tcf_police_mtu_check() always passes. TC_ACT_CONSUMED was added by commit 720f22fed81b ("net: sched: refactor reinsert action"), after both goto-chain guards were written: commit 9469f375ab09 ("net/sched: act_gact: disallow 'goto chain' on fallback control action") and commit c08f5ed5d625 ("net/sched: act_police: disallow 'goto chain' on fallback control action"). Neither guard was widened when the new verdict appeared. Factor the existing range test out of tcf_action_check_ctrlact() as tcf_action_valid() and apply it to both fallbacks. The helper cannot call tcf_action_check_ctrlact() directly because that also allocates a goto_chain, which is exactly what these two sites must not do. Reproduced on v7.2-rc6: kmemleak reports one leaked 232-byte skbuff_head_cache object plus its 704-byte data buffer per packet. With this patch both configurations are rejected with -EINVAL and kmemleak reports none. Fixes: 720f22fed81b ("net: sched: refactor reinsert action") Cc: stable@vger.kernel.org # v5.3+ Signed-off-by: Hyunjung Ko Acked-by: Jamal Hadi Salim Tested-by: Victor Nogueira Link: https://patch.msgid.link/20260806101252.809593-1-hj351016@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ipv6: prevent in6_dev_get() from resurrecting inet6_dev

2026-08-19T16:13:12+00:00

commit 0e243671bc7b8eaf00f83dd2f4367436dc0cff98 upstream. in6_dev_get() reads dev->ip6_ptr under RCU and then unconditionally increments its refcount. Device teardown can clear the pointer and drop the last reference between these operations. The increment then resurrects an object whose RCU free has already been queued, so callers can use it after it is freed. Use refcount_inc_not_zero() and return NULL when the object has already reached zero. RCU keeps the memory accessible through the attempted reference acquisition, and a successful increment pins the object for the caller. An independent run on the exact unpatched 6f5156d7a31a (v7.2-rc3) kernel reproduced the invalid reference acquisition as UID 1000: refcount_t: addition on 0; use-after-free. ip6_mc_source+0xef4/0x17e0 It was followed by the corresponding reference underflow in ip6_mc_source(). The supplied trace from the same unpatched revision additionally shows the access after the RCU read-side section ends: BUG: KASAN: slab-use-after-free in mutex_lock+0x76/0xe0 Write of size 8 at addr ffff888015b50240 by task poc/1219 Bug found and triaged by OpenAI Security Research and validated by Trail of Bits. Fixes: 8814c4b53381 ("[IPV6] ADDRCONF: Convert addrconf_lock to RCU.") Cc: stable@vger.kernel.org Signed-off-by: Kyle Zeng Co-developed-by: David Lee Signed-off-by: David Lee Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260803122758.666112-1-david.lee@trailofbits.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ipv4: fix use-after-free in fib_nhc_update_mtu()

2026-08-19T16:13:11+00:00

commit bc5bde9ce3cc36502839dfe98e068f7303a50982 upstream. fib_nhc_update_mtu() walks the nexthop exception table under RTNL, but RTNL does not serialize this walk with PMTU exception updates. The walk uses rcu_dereference_protected() with a constant true condition without holding fnhe_lock. The following interleaving can therefore occur: CPU 0 CPU 1 fib_nhc_update_mtu() update_or_create_fnhe() load fnhe spin_lock_bh(&fnhe_lock) fnhe_remove_oldest() unlink fnhe kfree_rcu(fnhe, rcu) access fnhe after grace period KASAN reported: BUG: KASAN: slab-use-after-free in fib_nhc_update_mtu+0x3df/0x410 Read of size 8 at addr ffff888107d49000 by task poc/90 Call Trace: fib_nhc_update_mtu+0x3df/0x410 fib_sync_mtu+0x7a/0xd0 fib_netdev_event+0x229/0x3f0 netif_set_mtu_ext+0x33a/0x570 dev_set_mtu+0x88/0x120 The same walk updates fnhe_pmtu and fnhe_mtu_locked. These fields form a pair and other writers serialize them with fnhe_lock. RCU alone prevents reclamation, but would still allow concurrent writers to leave a mixed pair. Walk the table under RCU and acquire fnhe_lock only while updating each exception. RCU keeps the current entry alive while the short critical section serializes its paired PMTU fields. This avoids holding the global lock while scanning all 2048 buckets for every nexthop. Fixes: af7d6cce5369 ("net: ipv4: update fnhe_pmtu when first hop's MTU changes") Cc: stable@vger.kernel.org Suggested-by: Ido Schimmel Signed-off-by: Chengfeng Ye Reviewed-by: Ido Schimmel Link: https://patch.msgid.link/20260807181710.1178747-1-nicoyip.dev@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

net: remove CAP_SYS_RAWIO zero-padding in dev_validate_header

2026-08-19T16:13:10+00:00

commit 3b9a324e646d3657a8d9806dfbfe4f3e4066e882 upstream. dev_validate_header() reads dev->hard_header_len directly when zero-padding short link layer headers for CAP_SYS_RAWIO holders: if (capable(CAP_SYS_RAWIO)) { memset(ll_header + len, 0, dev->hard_header_len - len); return true; } Packet send paths call dev_validate_header() on skbs whose headroom was allocated from an earlier hard_header_len read. If the device is reconfigured so that dev->hard_header_len increases before validation, the memset writes past the reserved buffer, an out-of-bounds write. This out-of-bounds write is masked in some SOCK_RAW paths today because the same concurrent increase can first make skb_push() exceed the reserved headroom and trigger skb_under_panic(). Remove the zero-padding branch before making those hard_header_len reads consistent, so the snapshot fixes do not turn a loud panic into a silent overwrite. This path is only reached for variable length L2 protocols, where len < hard_header_len but len >= min_header_len. No remaining in-tree variable length L2 protocol implements header_ops->validate, and the CAP_SYS_RAWIO bypass that zero-pads and accepts short headers has no real value beyond allowing testing of intentionally malformed input. Drop the CAP_SYS_RAWIO branch. The remaining reads of dev->hard_header_len in dev_validate_header() are comparisons only and have no memory safety impact. Suggested-by: Willem de Bruijn Fixes: 2793a23aacbd ("net: validate variable length ll headers") Cc: stable@vger.kernel.org Signed-off-by: Qihang Tang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260805125729.19220-2-q.h.hack.winter@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net/sched: reject overly deep qdisc hierarchies

2026-08-19T16:13:10+00:00

commit dedd34b0f2310e28c5f6d4875cfbf4b7ed821c01 upstream. Deep qdisc hierarchies can lead to excessive recursion in qdisc tree walkers and exhaust the kernel stack. The existing loop check does not cover the create-and-graft path, so a hierarchy can still be extended by creating a new child qdisc below an already deep parent. Store the hierarchy depth in struct Qdisc and update it when qdiscs are grafted. Reject new child qdiscs once the parent is already at the maximum allowed depth. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Suggested-by: Jamal Hadi Salim Reported-by: Vega Assisted-by: Codex:gpt-5.4 Signed-off-by: Zijie Huang Signed-off-by: Ren Wei Reviewed-by: Victor Nogueira Link: https://patch.msgid.link/1e9ab39597423fd5d13cfaaf52279b8ee3d9fc3c.1785434373.git.milkory@outlook.com Acked-by: Jamal Hadi Salim Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

packet: use consistent hard_header_len in non-ring send paths

2026-08-19T16:13:09+00:00

commit 03390aa32e669cc4ecd7d34108e2e1afc13d689d upstream. packet_snd() reads dev->hard_header_len multiple times while allocating and constructing an skb. Device reconfiguration can change this value concurrently, for example through bonding device type changes. For SOCK_RAW, packet_snd() can save a larger value in reserve and later allocate headroom using a smaller value. Moving skb->data back by reserve then places it before skb->head, and the following copy from userspace can attempt an out-of-bounds write. packet_sendmsg_spkt() has the same issue because it calculates its reservation and header offset from separate reads before dropping the RCU read lock to allocate the skb. Add LL_RESERVED_SPACE_EX() for callers that already saved a header length. Read hard_header_len once in packet_snd() and use it for allocation and construction. In packet_sendmsg_spkt(), preserve the allocation-time value through the device lookup retry. The separate SOCK_DGRAM consistency problem between hard_header_len and header_ops->create is not addressed here. Fixes: b84bbaf7a6c8 ("packet: in packet_snd start writing at link layer allocation") Cc: stable@vger.kernel.org Signed-off-by: Qihang Tang Reviewed-by: Willem de Bruijn Link: https://patch.msgid.link/20260805125729.19220-3-q.h.hack.winter@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

ipvs: properly update the overload flag on dest edit

2026-08-19T16:13:09+00:00

commit 8f843441c4e7eae8ea83491e8c203c2b192edcf5 upstream. The upper/lower connection thresholds for dest can be changed, so use ip_vs_dest_update_overload() to properly update the dest overload flag. The thresholds were not limited, fit them in the 0 .. INT_MAX range as already done in ipvsadm. As the thresholds are also read when connections are created and expired, use WRITE_ONCE/READ_ONCE to access them. As the lower threshold is optional, use (u - (u >> 2)) to calculate the 75% default value based on the upper threshold by preserving the integer rounding, as suggested by Yizhou Zhao. Trigger flag update when totalconns reaches one of the thresholds and use dst_lock to serialize the updating. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Julian Anastasov Signed-off-by: Yizhou Zhao Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

ipvs: add totalconns for dest

2026-08-19T16:13:09+00:00

commit 04d2feaed8d0103c498727191ba04001d5100e67 upstream. Replace the inactconns dest counter with totalconns, now inactconns can be obtained from totalconns - activeconns. This reduces the atomic inc/dec ops for TCP/SCTP from 6 to 4 if the connection is established and then closed. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Julian Anastasov Signed-off-by: Yizhou Zhao Signed-off-by: Pablo Neira Ayuso Signed-off-by: Greg Kroah-Hartman

regulator: devres: add API for reference voltage supplies

2026-08-19T16:13:08+00:00

[ Upstream commit b250c20b64290808aa4b5cc6d68819a7ee28237f ] A common use case for regulators is to supply a reference voltage to an analog input or output device. This adds a new devres API to get, enable, and get the voltage in a single call. This allows eliminating boilerplate code in drivers that use reference supplies in this way. Signed-off-by: David Lechner Link: https://lore.kernel.org/r/20240429-regulator-get-enable-get-votlage-v2-1-b1f11ab766c1@baylibre.com Signed-off-by: Mark Brown Stable-dep-of: fddb5ceaf901 ("hwmon: (ads7828) Fix external VREF regulator handling") Signed-off-by: Sasha Levin

net/tcp: Add TCP-AO config and structures

2026-08-19T16:13:08+00:00

[ Upstream commit c845f5f3590ef4669fe5464f8a42be6442cd174b ] Introduce new kernel config option and common structures as well as helpers to be used by TCP-AO code. Co-developed-by: Francesco Ruggeri Signed-off-by: Francesco Ruggeri Co-developed-by: Salam Noureddine Signed-off-by: Salam Noureddine Signed-off-by: Dmitry Safonov Acked-by: David Ahern Signed-off-by: David S. Miller Stable-dep-of: d0c80dbb9704 ("net/atm: fix slab-out-of-bounds read in vcc_setsockopt()") Signed-off-by: Sasha Levin