CVE-2026-31478

CRITICAL

ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len()

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: replace hardcoded hdr2_len with offsetof() in smb2_calc_max_out_buf_len() After this commit (e2b76ab8b5c9 "ksmbd: add support for read compound"), response buffer management was changed to use dynamic iov array. In the new design, smb2_calc_max_out_buf_len() expects the second argument (hdr2_len) to be the offset of ->Buffer field in the response structure, not a hardcoded magic number. Fix the remaining call sites to use the correct offsetof() value.

Scores

CVSS v3 9.8
EPSS 0.0010
EPSS Percentile 26.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Details

Status published
Products (21)
Linux/Linux < 6.6
Linux/Linux 5.15.145 - 5.15.203
Linux/Linux 5.15.203 - 5.15.*
Linux/Linux 6.1.168 - 6.1.*
Linux/Linux 6.1.71 - 6.1.168
Linux/Linux 6.12.80 - 6.12.*
Linux/Linux 6.18.21 - 6.18.*
Linux/Linux 6.19.11 - 6.19.*
Linux/Linux 6.6
Linux/Linux 6.6.131 - 6.6.*
... and 11 more
Published Apr 22, 2026
Tracked Since Apr 22, 2026