PT-2025-49095 · Linux+4 · Linux Kernel+4

Published

2025-11-04

·

Updated

2026-04-06

·

CVE-2025-40265

CVSS v2.0

4.0

Medium

VectorAV:A/AC:H/Au:S/C:P/I:P/A:P
Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.18.0-rc2+ #38
Description The Linux kernel had a flaw related to vfat filesystem handling when emulating an nvme device on qemu with specific block size settings. Specifically, when both logical block size and physical block size were set to 8 KiB without a format, a kernel panic occurred during early boot while attempting to mount a vfat filesystem. This was due to missing return value checks in the sb min blocksize() function. The issue triggered a kernel BUG at fs/buffer.c, leading to an invalid opcode and ultimately a system crash.
Recommendations Update to a version newer than 6.18.0-rc2+ #38.

Exploit

Fix

Unchecked Return Value

Found an issue in the description? Have something to add? Feel free to write us 👾

Weakness Enumeration

Related Identifiers

BDU:2025-15943
CVE-2025-40265
USN-8094-1
USN-8094-2
USN-8094-3
USN-8094-4
USN-8094-5
USN-8152-1

Affected Products

Linuxmint
Linux Kernel
Ubuntu
Qemu
Vfat