CVE-2025-38652: f2fs: fix to avoid out-of-boundary access in devs.path

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-22 · updated 2026-07-30
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid out-of-boundary access in devs.path - touch /mnt/f2fs/012345678901234567890123456789012345678901234567890123 - truncate -s $((1024*1024*1024)) \ /mnt/f2fs/012345678901234567890123456789012345678901234567890123 - touch /mnt/f2fs/file - truncate -s $((1024*1024*1024)) /mnt/f2fs/file - mkfs.f2fs /mnt/f2fs/012345678901234567890123456789012345678901234567890123 \ -c /mnt/f2fs/file - mount /mnt/f2fs/012345678901234567890123456789012345678901234567890123 \ /mnt/f2fs/loop [16937.192225] F2FS-fs (loop0): Mount Device [ 0]: /mnt/f2fs/012345678901234567890123456789012345678901234567890123\xff\x01, 511, 0 - 3ffff [16937.192268] F2FS-fs (loop0): Failed to find devices If device path length equals to MAX_PATH_LEN, sbi->devs.path[] may not end up w/ null character due to path array is fully filled, So accidently, fields locate after path[] may be treated as part of device path, result in parsing wrong device path. struct f2fs_dev_info { ... char path[MAX_PATH_LEN]; ... }; Let's add one byte space for sbi->devs.path[] to store null character of device path string.

Affected products

Debian Linux: 11.0
Linux kernel: from 4.10 before 5.4.297; from 5.5 before 5.10.241; from 5.11 before 5.15.190; from 5.16 before 6.1.148; from 6.2 before 6.6.102; from 6.7 before 6.12.42 — fixed in 5.10.241, 5.15.190, 5.4.297, 6.1.148, 6.12.42, 6.15.10

How to fix

Upgrade to a fixed version: Linux kernel 5.10.241, 5.15.190, 5.4.297, 6.1.148. Check the vendor advisory for mitigations.

References

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