CVE-2026-90321 ocfs2: validate inline xattrs during inode block validation
A use-after-free vulnerability in the Linux kernel's OCFS2 filesystem allows attackers to cause denial of service or execute code via corrupted inline xattr metadata.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2026-90321?
CVE-2026-90321 is a high-severity use after free vulnerability in Linux, published on 17 Sep 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: validate inline xattrs during inode block validation
Patch series "ocfs2: validate xattr entry bounds", v7.
This series validates OCFS2 xattr entry name/value bounds when xattr metadata is read and validated, before getxattr() or listxattr() can walk out-of-range entry arrays or offsets from corrupted metadata.
This patch (of 2):
ocfs2_validate_inode_block() verifies a dinode before OCFS2 users walk metadata from it, but inline xattr metadata is still checked only in operation-specific consumers. The existing ibody lookup helper validates inline header placement and entry count, but inode block validation does not reject entry name/value bounds.
Add a flat xattr entry validator and call it from inode block validation for inline xattrs. Keep the operation paths on their existing header/count lookup checks; the full entry bounds check now runs when the inode block is validated at read time.
Reject corrupted inline xattr metadata before ocfs2_xattr_ibody_get() or listxattr() can walk past the inline storage.
Validation reproduced this kernel report: BUG: KASAN: use-after-free in ocfs2_xattr_find_entry+0x5a/0x170 Read of size 2 at addr ffff8881242a2000 by task python3/529 Call Trace: dump_stack_lvl+0x66/0xa0 print_report+0xce/0x630 kasan_report+0xe0/0x110 ocfs2_xattr_find_entry+0x5a/0x170 ocfs2_xattr_get_nolock+0x20a/0x820 ocfs2_xattr_get+0x10c/0x1e0 __vfs_getxattr+0xe2/0x130 vfs_getxattr+0x185/0x1b0
Which versions are affected by CVE-2026-90321?
How do I fix CVE-2026-90321?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-90321 being exploited?
There is no known exploitation of CVE-2026-90321 in the wild and no public exploit code.
Sources
Also known as AZL-102530, BELL-CVE-2026-90321, DEBIAN-CVE-2026-90321, GHSA-wp5h-rffw-rh8w, UBUNTU-CVE-2026-90321.