CVE-2026-52929
Published: June 25, 2026Last modified: July 6, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: sctp: stream: fully roll back denied add-stream state When ADD_OUT_STREAMS is denied, SCTP only shrinks the queued chunks and then lowers outcnt. That leaves removed stream metadata behind, so a later re-add can reuse a stale ext and hit a null-pointer dereference in the scheduler get path. Fix the rollback by tearing down the removed stream state the same way other stream resizes do. Unschedule the current scheduler state, drop the removed stream ext state with sctp_stream_outq_migrate(), and then reschedule the remaining streams. This keeps scheduler-private RR/FC/PRIO lists consistent while fully rolling back denied outgoing stream additions.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.5 |
| Attack Vector | NETWORK |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | NONE |
| Integrity impact | NONE |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Fixed (6.1.177-r0) |
| 25 LTS | linux-lts | Fixed (6.12.95-r0) | |
| Stream | linux-lts | Fixed (6.18.38-r0) |
References
- https://git.kernel.org/stable/c/0cd2dc6dce8ca47212cd306ccd52eb315ef3cf85
- https://git.kernel.org/stable/c/1c6773b8c081509dcd5cd2954f2b02c50c00f151
- https://git.kernel.org/stable/c/39dc2b0eb5371a669ebc9ec6072b9184eac95418
- https://git.kernel.org/stable/c/7dd9a42b044aad2dbe037db1c1e2943582485b44
- https://git.kernel.org/stable/c/9662eb0401518f0b4681f10e7fbf688f504f24cf
- https://git.kernel.org/stable/c/a5f8a90ac9f77c678a9781c0a464b635e0d63e49
- https://git.kernel.org/stable/c/a6724b7b812ac8793514a1d5938db5d9d29ae725
- https://git.kernel.org/stable/c/d5ea0b3e261fcb2cfff142675516165244cab1da