Linux vulnerability

What happened

In the Linux kernel, the following vulnerability has been resolved: smb: client: harden POSIX SID length parsing posix_info_sid_size() reads sid[1] to obtain the subauthority count, but its existing boundary check still accepts buffers with only one remaining byte. Require two bytes before reading sid[1] so all client paths that reuse the helper reject truncated POSIX SIDs safely.

Affected versions

Linux: 349e13ad30b45998bb9937cfe0b32be6f951976d through before 171605aed68380c2fa75dff9b3a1ed427c50065b (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 4213c1208978483021d7d125c131de3985d38f61 (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 96e889bc1e759c83f25093e8c2f3da31b4973f30 (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 0de5b8e76847f5de26f364a82c6602c4881c30da (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 427eb7eb46425fec845a43e861f3d6e2899cae59 (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 86c5d470f5d42e61123b2f4b4f0b91f4eee5b980 (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 46a84715a015cb48e1b9c219dc88c03d8a541ea4 (git); 349e13ad30b45998bb9937cfe0b32be6f951976d through before 7ad2bcf2441430bb2e918fb3ef9a90d775a6e422 (git); 5.7 Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

• Apply vendor-provided updates or mitigations.
• Review affected product exposure and access logs.