CVE-2026-64380

Description

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.

References

• https://git.kernel.org/stable/c/0de5b8e76847f5de26f364a82c6602c4881c30da
• https://git.kernel.org/stable/c/171605aed68380c2fa75dff9b3a1ed427c50065b
• https://git.kernel.org/stable/c/4213c1208978483021d7d125c131de3985d38f61
• https://git.kernel.org/stable/c/427eb7eb46425fec845a43e861f3d6e2899cae59
• https://git.kernel.org/stable/c/46a84715a015cb48e1b9c219dc88c03d8a541ea4