CVE-2026-23233

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to avoid mapping wrong physical block for swapfile

Xiaolong Guo reported a f2fs bug in bugzilla [1]

[1] https://bugzilla.kernel.org/show_bug.cgi?id=220951

Quoted:

"When using stress-ng's swap stress test on F2FS filesystem with kernel 6.6+,

the system experiences data corruption leading to either:

1 dm-verity corruption errors and device reboot

2 F2FS node corruption errors and boot hangs

The issue occurs specifically when:

1 Using F2FS filesystem (ext4 is unaffected)

2 Swapfile size is less than F2FS section size (2MB)

3 Swapfile has fragmented physical layout (multiple non-contiguous extents)

4 Kernel version is 6.6+ (6.1 is unaffected)

The root cause is in check_swap_activate() function in fs/f2fs/data.c. When the

first extent of a small swapfile (< 2MB) is not aligned to section boundaries,

the function incorrectly treats it as the last extent, failing to map

subsequent extents. This results in inc

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References