Description
In the Linux kernel, the following vulnerability has been resolved: sctp: clear control chunk transport if it is being removed sctp_make_heartbeat_ack() caches the destination transport in chunk->transport without taking a reference. When src_out_of_asoc_ok is enabled, the HEARTBEAT ACK may remain queued on control_chunk_list instead of being transmitted immediately. If the peer transport is removed while the chunk is still queued, sctp_assoc_rm_peer() drops the transport and schedules it for RCU freeing, but only clears cached transport pointers in out_chunk_list. The queued control chunk therefore retains a dangling transport pointer. Once an ASCONF_ACK clears the suppression and the queued control chunk is transmitted, SCTP dereferences the stale transport pointer, leading to a use-after-free. Fix this by also clearing chunk->transport for queued control chunks in control_chunk_list when removing the transport.
References8
- git.kernel.org/stable/c/18d704bdd809377dfd81a3c2f42426763b5da227
- git.kernel.org/stable/c/4d6b9cac6df5e0cfef1a66b3edd7aebdb9e4b7e7
- git.kernel.org/stable/c/6160e756db81d6cb63e3e2952efcf6c5134be385
- git.kernel.org/stable/c/8de65194a04d2552cd39b6c67d942d490f22d174
- git.kernel.org/stable/c/936658ec41c28c397ef390140e02d4c91ade92f0
- git.kernel.org/stable/c/c9158ceaf27780ef64534ad72f44ffde3f8ccc49
- git.kernel.org/stable/c/dbb3f418a8665ffb0514e1a9520ab6a1c5d4d886
- git.kernel.org/stable/c/fad4766a74220fe579c6fcaa10ba01c23529814f
Metrics
- CVSS 3.1
-
9.8
CRITICAL
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 43 · as of 9 November 2026
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