CVE Catalog

CVE-2024-50015

MediumCVSS 5.5
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.24%

14th percentile - higher than 14% of all known CVEs

Summary

In the Linux kernel, a vulnerability was resolved in ext4: dax regarding overflowing extents beyond inode size when partially writing. If the process is killed by a signal during dax_iomap_rw(), the copied data is returned and added to the inode size, which means the length of written extents may exceed the inode size, causing fsck to fail. The fix truncates extents if the written length is smaller than expected.

Risk Assessment

Inconsistency in the ext4 filesystem with DAX can lead to fsck errors, data loss, or filesystem corruption after an interrupted write operation.

Recommendation

Update the Linux kernel to a version containing the fix that truncates extents in ext4 DAX on partial writes to ensure filesystem consistency.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: ext4: dax: fix overflowing extents beyond inode size when partially writing The dax_iomap_rw() does two things in each iteration: map written blocks and copy user data to blocks. If the process is killed by user(See signal handling in dax_iomap_iter()), the copied data will be returned and added on inode size, which means that the length of written extents may exceed the inode size, then fsck will fail. An example is given as: dd if=/dev/urandom of=file bs=4M count=1 dax_iomap_rw iomap_iter // round 1 ext4_iomap_begin ext4_iomap_alloc // allocate 0~2M extents(written flag) dax_iomap_iter // copy 2M data iomap_iter // round 2 iomap_iter_advance iter->pos += iter->processed // iter->pos = 2M ext4_iomap_begin ext4_iomap_alloc // allocate 2~4M extents(written flag) dax_iomap_iter fatal_signal_pending done = iter->pos - iocb->ki_pos // done = 2M ext4_handle_inode_extension ext4_update_inode_size // inode size = 2M fsck reports: Inode 13, i_size is 2097152, should be 4194304. Fix? Fix the problem by truncating extents if the written length is smaller than expected.

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