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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Wed, 06 May 2026 20:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125

Sun, 03 May 2026 06:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

cvssV3_1

{'score': 8.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H'}


Sat, 02 May 2026 11:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125

Sat, 02 May 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-805
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Sat, 02 May 2026 00:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-125

Fri, 01 May 2026 14:15:00 +0000

Type Values Removed Values Added
Description 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.
Title smb: client: fix OOB read in smb2_ioctl_query_info QUERY_INFO path
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T22:14:13.270Z

Reserved: 2026-03-09T15:48:24.132Z

Link: CVE-2026-31708

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Analyzed

Published: 2026-05-01T14:16:20.837

Modified: 2026-05-06T20:25:14.280

Link: CVE-2026-31708

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-01T00:00:00Z

Links: CVE-2026-31708 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-06T22:30:13Z

Weaknesses