Medium [CVE-2026-74536] fix leaking sk after socket release
This medium-severity Red Hat Linux advisory covers CVE-2026-74536 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9, Red Hat package: kernel-rt.
Android app · Google Play
Monitor future Red Hat Linux CVEs from your phone.
Choose a whole vendor or a precise platform, then receive matching security advisories by phone notification, email, or both. Coverage follows 32 official vendor sources and 160+ reviewed platform categories.
Summary
In the Linux kernel, the following vulnerability has been resolved: Bluetooth: ISO: fix leaking sk after socket release iso_sock_kill() tests!sock_flag(sk, SOCK_ZAPPED) || sk->sk_socket || sock_flag(sk, SOCK_DEAD) for early return, but this is always true since sock_orphan(sk) sets SOCK_DEAD, so the sk reference released by socket always leaks, iso_sock_destruct is never called.
The socket reference also leaks when __iso_sock_close() does not set SOCK_ZAPPED, since iso_conn_del() does not call iso_sock_kill() after zapping. Fix by replacing SOCK_DEAD by BT_SK_KILLED flag that is not used for something else, and lock_sock to ensure iso_sock_kill() puts sk only after socket release only once.
Release and iso_conn_del may run concurrently. Remove call to iso_sock_kill() from iso_sock_close(), as it's generally no-op there.
This vulnerability occurs due to an issue in how socket references are managed after a socket is released, specifically within the `iso_sock_kill()` and `__iso_sock_close()` functions. This improper handling leads to a memory leak, which a local attacker could exploit to exhaust system resources and cause a Denial of Service (DoS).
Red Hat severity: Low — CVSS 5.5 (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H). Weakness: CWE-911.
Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Mitigation
The source record does not include mitigation steps. That is not a statement that no fix exists — read the vendor advisory below for the authoritative guidance.
Official advisory · medium-confidence parse· fetched 1 hour ago·verify at source
Discussion(0)
No comments yet. Share field notes, upgrade gotchas, or questions — verify against the vendor advisory before acting on community advice.
Sign in to join the discussion.