Description
In the Linux kernel, the following vulnerability has been resolved:

sctp: revalidate output stream after association connect wait

When message interleaving is enabled, the first send waits for association
establishment before building its data chunks. The wait drops the socket
lock, and handshake processing can reduce the output stream count to the
peer-advertised inbound stream count. sctp_stream_init() then frees the
extension of every removed stream.

The sender resumes with the stream that it checked before the wait. If the
peer removed that stream, sctp_outq_tail() later dereferences its NULL
extension. Fatal-oops policies then panic the host.

KASAN: null-ptr-deref in range [0x38-0x3f]
RIP: sctp_outq_tail+0x49e/0xaa0
Call Trace:
sctp_primitive_SEND
sctp_sendmsg_to_asoc
sctp_sendmsg

A range check alone is insufficient. Stream reconfiguration can grow the
output count again while the lock is released without recreating extensions
freed by the earlier shrink. The stream can then be in range while its
extension remains NULL. The send-buffer wait has the same issue.

Factor the range and extension checks into a helper and repeat both after
each send-path wait that drops the socket lock. Once the lock is
reacquired, the validation remains stable through data creation and
queueing.

If validation fails after the connect wait, the auto-created association is
already established. Return ESRCH so the existing caller path keeps it
under state-machine ownership instead of freeing it directly, which would
leave protocol, counter and socket state inconsistent.
Published: 2026-10-28
Score: n/a
EPSS: n/a
KEV: No
Impact: n/a
Action: n/a
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Remediation

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History

Wed, 28 Oct 2026 10:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: sctp: revalidate output stream after association connect wait When message interleaving is enabled, the first send waits for association establishment before building its data chunks. The wait drops the socket lock, and handshake processing can reduce the output stream count to the peer-advertised inbound stream count. sctp_stream_init() then frees the extension of every removed stream. The sender resumes with the stream that it checked before the wait. If the peer removed that stream, sctp_outq_tail() later dereferences its NULL extension. Fatal-oops policies then panic the host. KASAN: null-ptr-deref in range [0x38-0x3f] RIP: sctp_outq_tail+0x49e/0xaa0 Call Trace: sctp_primitive_SEND sctp_sendmsg_to_asoc sctp_sendmsg A range check alone is insufficient. Stream reconfiguration can grow the output count again while the lock is released without recreating extensions freed by the earlier shrink. The stream can then be in range while its extension remains NULL. The send-buffer wait has the same issue. Factor the range and extension checks into a helper and repeat both after each send-path wait that drops the socket lock. Once the lock is reacquired, the validation remains stable through data creation and queueing. If validation fails after the connect wait, the auto-created association is already established. Return ESRCH so the existing caller path keeps it under state-machine ownership instead of freeing it directly, which would leave protocol, counter and socket state inconsistent.
Title sctp: revalidate output stream after association connect wait
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-28T10:35:17.366Z

Reserved: 2026-09-25T10:25:14.398Z

Link: CVE-2026-99165

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-28T11:17:36.917

Modified: 2026-10-28T11:17:36.917

Link: CVE-2026-99165

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-10-28T13:15:18Z

Weaknesses

No weakness.