CVE-2026-98169

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

HIGH
7.1
CVSS Score
Published: October 6, 2026 at 08:44 AM UTC
Updated: October 30, 2026 at 01:21 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.1
Exploit prediction
EPSS 0.4%

Description

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.

Affected

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

Vendor states this is fixed in 4.19 (unaffected)
Vendor states this is fixed in 6.1.* (unaffected)
Vendor states this is fixed in 6.1.189 (unaffected)
Vendor states this is fixed in 6.12.* (unaffected)
Vendor states this is fixed in 6.12.112 (unaffected)
Vendor states this is fixed in 6.18.* (unaffected)
Vendor states this is fixed in 6.18.54 (unaffected)
Vendor states this is fixed in 6.6.* (unaffected)
Vendor states this is fixed in 6.6.158 (unaffected)
Vendor states this is fixed in 7.2.* (unaffected)
Vendor states this is fixed in 7.2.8 (unaffected)
Vendor states this is fixed in 7.3 (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.

CVSS

7.1HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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