Home/CVE/In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read in smb2_ioctl_query_info
CVE

CVE-2026-31708

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read in smb2_ioctl_query_info

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path smb2_ioctl_query_info() has two response-copy branches: PASSTHRU_FSCTL and the default QUERY_INFO path. The QUERY_INFO branch clamps qi.input_buffer_length to the server-reported OutputBufferLength and then copies qi.input_buffer_length bytes from qi_rsp-Buffer to userspace, but it never verifies that the flexible-array payload actually fits within rsp_iov[1].iov_len. A malicious server can return OutputBufferLength larger than the actual QUERY_INFO response, causing copy_to_user() to walk past the response buffer and expose adjacent kernel heap to userspace.

Guard the QUERY_INFO copy with a bounds check on the actual Buffer payload. Use struct_size(qi_rsp, Buffer, qi.input_buffer_length) rather than an open-coded addition so the guard cannot overflow on 32-bit builds.

HIGH · CVSS 8.1 EPSS 0.00055
Schedule remediation
  • CVSS base score ≥ 7.0
Sigma rules0 YARA rules0

Weakness Classification

Affected Products & Versions

4
linux kernel>= 5.1 and < 6.6.136
linux kernel>= 6.7 and < 6.12.84
linux kernel>= 6.13 and < 6.18.25
linux kernel>= 6.19 and < 7.0.2

Scoring & Timeline

8.1
HIGH · CVSS v3.1 · 416baaa9-dc9f-4396-8d5f-8c081fb06d67
View on NVD
Attack Vector
Network Adjacent Local Physical
Attack Complexity
Low High
Privileges Required
None Low High
User Interaction
None Required
Scope
Unchanged Changed
Confidentiality
None Low High
Integrity
None Low High
Availability
None Low High
Published to NVD01 May 2026 · 02:16 PM
CVSS VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

Vendor Advisories

2
suse-csafopenSUSE-SU-2026:10793-1
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