ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access
At a glance
Severity
Not available
EPSS
EPSS 0.13 % · percentile 2 (2026-10-27)
State
PUBLISHED
Published
Updated
Assigner
Linux
NVD status
Analyzed
Description
In the Linux kernel, the following vulnerability has been resolved:
ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access
The bounds check for the next xattr entry in check_xattrs() uses
(void *)next >= end, which allows next to point within sizeof(u32)
bytes of end. On the next loop iteration, IS_LAST_ENTRY() reads 4
bytes via *(__u32 *)(entry), which can overrun the valid xattr region.
For example, if next lands at end - 1, the check passes since
next < end, but IS_LAST_ENTRY() reads 4 bytes starting at end - 1,
accessing 3 bytes beyond the valid region.
Fix this by changing the check to (void *)next + sizeof(u32) > end,
ensuring there is always enough space for the IS_LAST_ENTRY() read
on the subsequent iteration.
