CVE-2026-53004
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: fix OOB write to userspace in sctp_getsockopt_peer_auth_chunks sctp_getsockopt_peer_auth_chunks() checks that the caller's optval buffer is large enough for the peer AUTH chunk list with if (len < num_chunks) return -EINVAL; but then writes num_chunks bytes to p->gauth_chunks, which lives at offset offsetof(struct sctp_authchunks, gauth_chunks) == 8 inside optval. The check is missing the sizeof(struct sctp_authchunks) = 8-byte header. When the caller supplies len == num_chunks (for any num_chunks > 0) the test passes but copy_to_user() writes sizeof(struct sctp_authchunks) = 8 bytes past the declared buffer. The sibling function sctp_getsockopt_local_auth_chunks() at the next line already has the correct check: if (len < sizeof(struct sctp_authchunks) + num_chunks) return -EINVAL; Align the peer variant with its sibling. Reproducer confirms on v7.0-13-generic: an unprivileged userspace caller that opens a loopback SCTP association with AUTH enabled, queries num_chunks with a short optval, then issues the real getsockopt with len == num_chunks and sentinel bytes painted past the buffer observes those sentinel bytes overwritten with the peer's AUTH chunk type. The bytes written are under the peer's control but land in the caller's own userspace; this is not a kernel memory corruption, but it is a kernel-side contract violation that can silently corrupt adjacent userspace data.
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/0cf004ffb61cd32d140531c3a84afe975f9fc7ea
- https://git.kernel.org/stable/c/2b5a2c957c7769d40110f725cf23987fcef50d75
- https://git.kernel.org/stable/c/6849b995cda88a677bf08a05765d1db7905974fc
- https://git.kernel.org/stable/c/6bcf8fe4ef7967b22b814cbae9a57bbd3c853410
- https://git.kernel.org/stable/c/70a089cc9590aa347a61e84434116ab74619e3c3
- https://git.kernel.org/stable/c/a132e199de69e2a45628aa8534df1bf5d44e1b6e
- https://git.kernel.org/stable/c/d45c7e99caf915b0f6c716bd8ffe9d45b9685761
- https://git.kernel.org/stable/c/d67fbc6dea5dbf7f46c618ebf65910a276078e20
Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.