CVE Catalog

CVE-2025-38415

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.17%

6th percentile - higher than 6% of all known CVEs

Summary

A vulnerability has been identified in the Squashfs filesystem in the Linux kernel that may lead to a 'shift-out-of-bounds' error. The issue occurs when two processes attempt to mount the Squashfs filesystem on the same device simultaneously, resulting in incorrect block size settings.

Risk Assessment

This vulnerability may lead to system crashes or unpredictable behavior of applications using the Squashfs filesystem, potentially impacting system stability and security.

Recommendation

It is recommended to update the Linux kernel to the latest version that includes the fix for this vulnerability. Additionally, monitor filesystem mounting processes to avoid simultaneous operations.

Related vulnerabilities

Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: Squashfs: check return result of sb_min_blocksize Syzkaller reports an "UBSAN: shift-out-of-bounds in squashfs_bio_read" bug. Syzkaller forks multiple processes which after mounting the Squashfs filesystem, issues an ioctl("/dev/loop0", LOOP_SET_BLOCK_SIZE, 0x8000). Now if this ioctl occurs at the same time another process is in the process of mounting a Squashfs filesystem on /dev/loop0, the failure occurs. When this happens the following code in squashfs_fill_super() fails. ---- msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE); msblk->devblksize_log2 = ffz(~msblk->devblksize); ---- sb_min_blocksize() returns 0, which means msblk->devblksize is set to 0. As a result, ffz(~msblk->devblksize) returns 64, and msblk->devblksize_log2 is set to 64. This subsequently causes the UBSAN: shift-out-of-bounds in fs/squashfs/block.c:195:36 shift exponent 64 is too large for 64-bit type 'u64' (aka 'unsigned long long') This commit adds a check for a 0 return by sb_min_blocksize().

Vulnerability data from NVD (NIST) · CISA KEV · EPSS