CVE-2026-74630
Description
In the Linux kernel, the following vulnerability has been resolved: ipv6: prevent in6_dev_get() from resurrecting inet6_dev 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.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No mitigations published for this CVE yet.
The vendor-content worker queues fetches as references arrive (check back in a few minutes). Or — if you've already worked around this in production — publish your fix to the community-verified tier.
Propose a mitigation on Community Mitigations published via the community go through AI scoring + 2 human reviewers + 7-day silent objection window before landing here withsource_tier=community-verified.
References
- https://git.kernel.org/stable/c/0e243671bc7b8eaf00f83dd2f4367436dc0cff98
- https://git.kernel.org/stable/c/145812b678de9f3b59780173be3c0d22ed60dd93
- https://git.kernel.org/stable/c/14e812ab41df0cac033479da835ec9a5de633404
- https://git.kernel.org/stable/c/1c206d461c680c3151daa3c89fc26eaf5bf98a7f
- https://git.kernel.org/stable/c/680fbd7942185448eadb990a3d10a53eb946b702
- https://git.kernel.org/stable/c/785d908f8d21c8bc78b6fb2c2932ab662bf6918a
- https://git.kernel.org/stable/c/aedcfefdb5b7ed7f8a6196a3e68a25bdbe51d2f8
- https://git.kernel.org/stable/c/cc5bd568f9b7683e60841b6fd02c10d64535bd6e
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.