CVE-2024-49996 Information

Description

In the Linux kernel the following vulnerability has been resolved:

cifs: Fix buffer overflow when parsing NFS reparse points

ReparseDataLength is sum of the InodeType size and DataBuffer size. So to get DataBuffer size it is needed to subtract InodeType’s size from ReparseDataLength.

Function cifs_strndup_from_utf16() is currentlly accessing buf->DataBuffer at position after the end of the buffer because it does not subtract InodeType size from the length. Fix this problem and correctly subtract variable len.

Member InodeType is present only when reparse buffer is large enough. Check for ReparseDataLength before accessing InodeType to prevent another invalid memory access.

Major and minor rdev values are present also only when reparse buffer is large enough. Check for reparse buffer size before calling reparse_mkdev().

CVSS Vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Reference

https://git.kernel.org/stable/c/c6db81c550cea0c73bd72ef55f579991e0e4ba07 https://git.kernel.org/stable/c/803b3a39cb096d8718c0aebc03fd19f11c7dc919 https://git.kernel.org/stable/c/c173d47b69f07cd7ca08efb4e458adbd4725d8e9 https://git.kernel.org/stable/c/e2a8910af01653c1c268984855629d71fb81f404

Attack Complexity

LOW

Privileges Required

LOW

User Interaction Required

LOW

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

7.8