CVE-2025-39964

crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg

State: Published
Severity: 7.8 High
Published: Oct 13, 2025
Updated: Oct 15, 2026
Reserved: Apr 16, 2025

Description

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

crypto: af_alg - Disallow concurrent writes in af_alg_sendmsg

Issuing two writes to the same af_alg socket is bogus as the data will be interleaved in an unpredictable fashion. Furthermore, concurrent writes may create inconsistencies in the internal socket state.

Disallow this by adding a new ctx->write field that indiciates exclusive ownership for writing.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

Affected Products

Product	Versions
LinuxLinux	8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 0f28c4adbc4a97437874c9b669fd7958a8c6d6ceAffected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before e4c1ec11132ec466f7362a95f36a506ce4dc08c9Affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8Affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 7c4491b5644e3a3708f3dbd7591be0a570135b84Affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 9aee87da5572b3a14075f501752e209801160d3dAffected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 45bcf60fe49b37daab1acee57b27211ad1574042Affected 8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285Affected
LinuxLinux	2.6.38Affected before 2.6.38Not affected 5.10.245 through 5.10.Not affected 5.15.194 through 5.15.Not affected 6.1.154 through 6.1.Not affected 6.6.108 through 6.6.Not affected 6.12.49 through 6.12.Not affected 6.16.9 through 6.16.Not affected 6.17 and laterNot affected

Product

Versions

LinuxLinux

8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 0f28c4adbc4a97437874c9b669fd7958a8c6d6ceAffected
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before e4c1ec11132ec466f7362a95f36a506ce4dc08c9Affected
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 1f323a48e9b5ebfe6dc7d130fdf5c3c0e92a07c8Affected
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 7c4491b5644e3a3708f3dbd7591be0a570135b84Affected
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 9aee87da5572b3a14075f501752e209801160d3dAffected
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 45bcf60fe49b37daab1acee57b27211ad1574042Affected
8ff590903d5fc7f5a0a988c38267a3d08e6393a2 to before 1b34cbbf4f011a121ef7b2d7d6e6920a036d5285Affected

LinuxLinux

2.6.38Affected
before 2.6.38Not affected
5.10.245 through 5.10.*Not affected
5.15.194 through 5.15.*Not affected
6.1.154 through 6.1.*Not affected
6.6.108 through 6.6.*Not affected
6.12.49 through 6.12.*Not affected
6.16.9 through 6.16.*Not affected
6.17 and laterNot affected

References

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