CVE-2022-50770 ocfs2: fix memory leak in ocfs2_mount_volume()
A memory leak in the Linux kernel OCFS2 filesystem allows local attackers to cause denial of service by exhausting kernel memory during mount operations.
- 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-2022-50770?
CVE-2022-50770 is a memory corruption vulnerability in Linux, published on 24 Dec 2025. 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 memory leak in ocfs2_mount_volume()
There is a memory leak reported by kmemleak:
unreferenced object 0xffff88810cc65e60 (size 32): comm "mount.ocfs2", pid 23753, jiffies 4302528942 (age 34735.105s) hex dump (first 32 bytes): 10 00 00 00 00 00 00 00 00 01 01 01 01 01 01 01 ................ 01 01 01 01 01 01 01 01 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8170f73d>] __kmalloc+0x4d/0x150 [<ffffffffa0ac3f51>] ocfs2_compute_replay_slots+0x121/0x330 [ocfs2] [<ffffffffa0b65165>] ocfs2_check_volume+0x485/0x900 [ocfs2] [<ffffffffa0b68129>] ocfs2_mount_volume.isra.0+0x1e9/0x650 [ocfs2] [<ffffffffa0b7160b>] ocfs2_fill_super+0xe0b/0x1740 [ocfs2] [<ffffffff818e1fe2>] mount_bdev+0x312/0x400 [<ffffffff819a086d>] legacy_get_tree+0xed/0x1d0 [<ffffffff818de82d>] vfs_get_tree+0x7d/0x230 [<ffffffff81957f92>] path_mount+0xd62/0x1760 [<ffffffff81958a5a>] do_mount+0xca/0xe0 [<ffffffff81958d3c>] __x64_sys_mount+0x12c/0x1a0 [<ffffffff82f26f15>] do_syscall_64+0x35/0x80 [<ffffffff8300006a>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
This call stack is related to two problems. Firstly, the ocfs2 super uses "replay_map" to trace online/offline slots, in order to recover offline slots during recovery and mount. But when ocfs2_truncate_log_init() returns an error in ocfs2_mount_volume(), the memory of "replay_map" will not be freed in error handling path. Secondly, the memory of "replay_map" will not be freed if d_make_root() returns an error in ocfs2_fill_super(). But the memory of "replay_map" will be freed normally when completing recovery and mount in ocfs2_complete_mount_recovery().
Fix the first problem by adding error handling path to free "replay_map" when ocfs2_truncate_log_init() fails. And fix the second problem by calling ocfs2_free_replay_slots(osb) in the error handling path "out_dismount". In addition, since ocfs2_free_replay_slots() is static, it is necessary to remove its static attribute and declare it in header file.
Which versions are affected by CVE-2022-50770?
How do I fix CVE-2022-50770?
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-2022-50770 being exploited?
There is no known exploitation of CVE-2022-50770 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50770, GHSA-5phr-qvw5-5rg9, UBUNTU-CVE-2022-50770.