Description
In the Linux kernel, the following vulnerability has been resolved: net/af_iucv: fix NULL deref in afiucv_hs_callback_syn() afiucv_hs_callback_syn() allocates the child socket with GFP_ATOMIC. If the allocation fails, nsk is NULL. The connection-refused path is entered when the listen state check fails, the accept backlog is full, or nsk is NULL. The code unconditionally calls iucv_sock_kill(nsk) in that path. iucv_sock_kill() does not accept a NULL socket pointer and immediately dereferences sk via sock_flag(sk, SOCK_ZAPPED). When nsk is NULL, calling iucv_sock_kill(nsk) results in a NULL pointer dereference. Only call iucv_sock_kill() when a child socket was successfully allocated.
References8
- git.kernel.org/stable/c/07e21deb3664001995e0a456dd627ab7dbe127ec
- git.kernel.org/stable/c/0e857185591fe79934427c9c0c1c31dc776be134
- git.kernel.org/stable/c/33736ff5e7c97d3348ce812e8bd2e125d840743c
- git.kernel.org/stable/c/46453b16f38ec7147351f7447e2aec6ea330f7b3
- git.kernel.org/stable/c/47a5116e56a6b6fe1e909f244e39cd0fc26ceee4
- git.kernel.org/stable/c/6a1eb5b46c19073f8153b7e2c19b408cf353aaf1
- git.kernel.org/stable/c/8bb111f87ded6acb9837ec9b45d6f02cda94c51f
- git.kernel.org/stable/c/c0b6e2ae90613c2fea7eaf3faa20985c6c2a1953
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: CNA
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 45 · as of 12 November 2026
- CWE
- CWE-476
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