CVE-2026-98168: smb: client: fix reparse buffer bounds in cifs_query_reparse_point()

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-10-06 · updated 2026-10-21

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix reparse buffer bounds in cifs_query_reparse_point() In cifs_query_reparse_point(), the start >= end check before casting to struct reparse_data_buffer * only ensures the start pointer is within the response. It fails to verify that there is enough space remaining for the fixed 8-byte header of the structure. If a server provides a DataOffset that leaves less than 8 bytes remaining, the check passes, but subsequent reads of ReparseTag and ReparseDataLength will occur out-of-bounds. Fix this by ensuring the remaining space is at least the size of the reparse_data_buffer structure before accessing its fields.

Affected products

Linux kernel: from 6.6.94 before 6.6.160; from 6.12.34 before 6.12.112; from 6.15.3 before 6.16; 6.16 — fixed in 6.12.112, 6.16, 6.6.160, 7.3

How to fix

Upgrade to a fixed version: Linux kernel 6.12.112, 6.16, 6.6.160, 7.3. Check the vendor advisory for mitigations.

References

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