CVE-2026-74628

CVE CVE-2026-74628EUVD EUVD-2026-64565Published 2026-08-22T15:32:10.000ZLast changed 2026-08-27T12:39:49.000ZCVSS 9.8

What the advisory describes

In the Linux kernel, the following vulnerability has been resolved: net/x25: fix use-after-free of the socket by its timers The x25 timers are armed with mod_timer() and cancelled with timer_delete(), so a pending timer holds no reference on the socket and a cancel does not wait for a callback already running on another CPU. x25_heartbeat_expiry() also rearms unconditionally, so it can reinstall sk->sk_timer after __x25_destroy_socket() has passed its cancel point. The following __sock_put() frees the socket while the timer is still queued, and the next expiry uses freed memory. KASAN reports a slab-use-after-free on the kmalloc-2k object freed by close(). timer_delete_sync() cannot be used here: x25_heartbeat_expiry() and x25_timer_expiry() both reach the cancels from inside the timer they would wait on, through __x25_destroy_socket() and x25_disconnect(). Arm the timers with sk_reset_timer() and cancel them with sk_stop_timer() so that an armed timer owns a reference, and release it in both expiry handlers. Rearm the heartbeat only while sk_hashed(sk) is still true, since __x25_destroy_socket() unlinks the socket before dropping it. Arm the deferred destroy timer the same way and drop its reference in x25_destroy_timer(). Reproduced on net with KASAN, with the heartbeat period shortened so the window recurs. With this patch the reproducer no longer triggers a report and /proc/net/x25 drains. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com>

Source: EUVD (ENISA), in the words of the advisory.

Products the advisory names

These come from the advisory itself, not from any check we performed.

• Linux — Linux 2.6.12; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <e92c7e2b41d1528a830bc64c5e4e46dfa8133dda; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <1fc9f6d2c7c9fdb341bfe8ca449c990632299ea6; patch: 6.6.153; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <4bc522b33438fefc3272840ae5988771863a4f1f; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <2195424c3da2ef1829a63b807e3a900a90e57d85; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <fdd9ac50b9b61ef2b2d52c5156aff788be91454d; patch: 7.2; patch: 6.1.184; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <6b79659590f0f82a9b8efd2ffd55ec6399ebfc33; patch: 6.12.105; patch: 7.1.9; patch: 0; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <3c4919be5d910db4beebca420953858606fba7d8; patch: 6.18.45; patch: 5.15.217; patch: 5.10.267; 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ba925a2e98ce967a0e71c5bcbcf5dbd3facaf0c8

The versions shown are the advisory's own. Patchlage compares no version numbers and derives no judgement from them — which version is installed is something a person has to look up.

Carried in the product catalogue

An estate covering these products can be recorded in Patchlage. An advisory about them appears in the next morning's situation report.

• Linux — Linux

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