Bug 2546354 (CVE-2026-98169) - CVE-2026-98169 kernel: smb: client: fix potential OOB read in smb3_enum_snapshots()
Summary: CVE-2026-98169 kernel: smb: client: fix potential OOB read in smb3_enum_snaps...
Keywords:
Status: NEW
Alias: CVE-2026-98169
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-06 09:04 UTC by OSIDB Bzimport
Modified: 2026-10-06 19:18 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-10-06 09:04:42 UTC
In the Linux kernel, the following vulnerability has been resolved:

smb: client: fix potential OOB read in smb3_enum_snapshots()

If snapshot_array_size is smaller than GMT_TOKEN_SIZE,
smb3_enum_snapshots() sets ret_data_len to
sizeof(struct smb_snapshot_array) without verifying the actual length
of the server's reply.

Because SMB2_ioctl() places no lower bound on the server-supplied
OutputCount and allocates retbuf to exactly that length, a short reply
results in ret_data_len exceeding the size of retbuf. The subsequent
copy_to_user() then reads past the end of retbuf, leaking adjacent slab
memory to userspace.  The subsequent clamp check is ineffective as it
only reduces ret_data_len.

Fix this by rejecting replies shorter than
sizeof(struct smb_snapshot_array) with -EIO. Note that the bound is set
to the 12-byte struct size rather than the 16-byte
MIN_SNAPSHOT_ARRAY_SIZE defined in MS-SMB2 3.3.5.15.1, because 12 bytes
is exactly what copy_to_user() attempts to read.


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