5.5

CVE-2026-64139

ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow

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

ksmbd: fix SID memory leak in set_posix_acl_entries_dacl() on overflow

Commit 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16
DACL size overflow") added check_add_overflow() guards that break out
of the ACE-building loops in set_posix_acl_entries_dacl() when the
accumulated DACL size would wrap past 65535.

However, each iteration allocates a struct smb_sid via kmalloc_obj()
at the top of the loop and relies on the kfree(sid) call at the end
of the loop body (the 'pass_same_sid' label in the first loop, and
the explicit kfree at the tail of the second loop) to release it.
The newly introduced 'break' statements bypass those kfree() calls,
leaking the sid buffer every time an overflow is detected.

A malicious or malformed file with enough POSIX ACL entries to trip
the overflow check will leak one or more struct smb_sid allocations
on every request that touches the file's DACL, providing a trivial
kernel memory exhaustion vector.

Free sid before breaking out of the loops to plug the leak.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
LinuxLinux Kernel Version >= 6.1.175 < 6.2
LinuxLinux Kernel Version >= 6.6.136 < 6.6.142
LinuxLinux Kernel Version >= 6.12.84 < 6.12.92
LinuxLinux Kernel Version >= 6.18.25 < 6.18.34
LinuxLinux Kernel Version >= 7.0.2 < 7.0.11
LinuxLinux Kernel Version7.1 Updaterc1
LinuxLinux Kernel Version7.1 Updaterc2
LinuxLinux Kernel Version7.1 Updaterc3
LinuxLinux Kernel Version7.1 Updaterc4
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.14% 0.035
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
NIST 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-401 Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

https://git.kernel.org/stable/c/9d378e17c864da08c3a4df41dae92cfa6468b00a
Patch
https://git.kernel.org/stable/c/519fb0a42ce5d7e46935577309fb282a5f2c6ea3
Patch
https://git.kernel.org/stable/c/0e198f09cb2a554c04de0fea4e790f1250a943ca
Patch
https://git.kernel.org/stable/c/eced48cb08f07393a5ea770fdd1026452883c3ad
Patch
https://git.kernel.org/stable/c/af92ee994cc7f7e83a41c2025f32257a2f82a7ef
Patch
https://git.kernel.org/stable/c/9b0a8985b419a71ee1cc9c0cc6a9e1bb7815a2c5