CVE-2026-97561

smb: client: honor forceuid/forcegid when mapping SIDs to uid/gid

N/A
Published: September 25, 2026 at 10:21 AM UTC
Updated: October 21, 2026 at 01:21 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
N/A
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: honor forceuid/forcegid when mapping SIDs to uid/gid When the administrator mounts with forceuid or forcegid (uid=/gid= mount options), they expect all files to appear owned by the specified user/group. However, several code paths unconditionally called sid_to_id() to overwrite cf_uid/cf_gid with server-provided values, ignoring the administrator's explicit override: - smb311_posix_info_to_fattr() (stat via POSIX extensions) - cifs_posix_to_fattr() (readdir via POSIX extensions) - parse_sec_desc() (CIFS ACL ownership mapping) This allowed an untrusted server to dictate local file ownership even when the mount was configured to force specific uid/gid values. Fix all three call sites to check CIFS_MOUNT_OVERR_UID and CIFS_MOUNT_OVERR_GID before calling sid_to_id(), following the same pattern already used by cifs_unix_basic_to_fattr() for unix extensions.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

3.09409ae58e0759d010b347e7b19ebc90ab5d4b98f
Vendor states this is fixed in 18a72975e9f35aadecc75b031f693f2d1f49308f (fixed)
Vendor states this is fixed in e1b74f8f8c1d13190b09fe623b729d36b7ac22a8 (fixed)
Vendor states this is fixed in 3.0 (unaffected)
Vendor states this is fixed in 6.12.114 (unaffected)
Vendor states this is fixed in 6.18.57 (unaffected)
Vendor states this is fixed in 6.6.160 (unaffected)
Vendor states this is fixed in 7.2.7 (unaffected)
Vendor states this is fixed in 7.3 (unaffected)
Vendor states this is fixed in 7.3-rc3 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

Quick Info

StatusRECEIVED

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