CVE-2026-53041 ocfs2: fix listxattr handling when the buffer is full
A local attacker can trigger a kernel crash in the OCFS2 filesystem by exploiting a buffer overflow in listxattr handling when inline and block xattrs are present.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-53041?
CVE-2026-53041 is a high-severity memory corruption vulnerability in Linux kernel, published on 24 Jun 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
ocfs2: fix listxattr handling when the buffer is full
[BUG] If an OCFS2 inode has both inline and block-based xattrs, listxattr() can return a size larger than the caller's buffer when the inline names consume that buffer exactly.
kernel BUG at mm/usercopy.c:102! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI RIP: 0010:usercopy_abort+0xb7/0xd0 mm/usercopy.c:102 Call Trace: __check_heap_object+0xe3/0x120 mm/slub.c:8243 check_heap_object mm/usercopy.c:196 [inline] __check_object_size mm/usercopy.c:250 [inline] __check_object_size+0x5c5/0x780 mm/usercopy.c:215 check_object_size include/linux/ucopysize.h:22 [inline] check_copy_size include/linux/ucopysize.h:59 [inline] copy_to_user include/linux/uaccess.h:219 [inline] listxattr+0xb0/0x170 fs/xattr.c:926 filename_listxattr fs/xattr.c:958 [inline] path_listxattrat+0x137/0x320 fs/xattr.c:988 __do_sys_listxattr fs/xattr.c:1001 [inline] __se_sys_listxattr fs/xattr.c:998 [inline] __x64_sys_listxattr+0x7f/0xd0 fs/xattr.c:998 ...
[CAUSE] Commit 936b8834366e ("ocfs2: Refactor xattr list and remove ocfs2_xattr_handler().") replaced the old per-handler list accounting with ocfs2_xattr_list_entry(), but it kept using size == 0 to detect probe mode.
That assumption stops being true once ocfs2_listxattr() finishes the inline-xattr pass. If the inline names fill the caller buffer exactly, the block-xattr pass runs with a non-NULL buffer and a remaining size of zero. ocfs2_xattr_list_entry() then skips the bounds check, keeps counting block names, and returns a positive size larger than the supplied buffer.
[FIX] Detect probe mode by testing whether the destination buffer pointer is NULL instead of whether the remaining size is zero.
That restores the pre-refactor behavior and matches the OCFS2 getxattr helpers. Once the remaining buffer reaches zero while more names are left, the block-xattr pass now returns -ERANGE instead of reporting a size larger than the allocated list buffer.
Weakness: CWE-787
Which versions are affected by CVE-2026-53041?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-53041?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-53041 being exploited?
There is no known exploitation of CVE-2026-53041 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2026-53041, DEBIAN-CVE-2026-53041, GHSA-gmx4-g5vq-2x9x, ROOT-OS-DEBIAN-11-CVE-2026-53041, ROOT-OS-DEBIAN-12-CVE-2026-53041, ROOT-OS-UBUNTU-2204-CVE-2026-53041 and 2 more.