CVE-2022-50193 erofs: wake up all waiters after z_erofs_lzma_head ready
A race condition in the Linux kernel EROFS filesystem can cause a denial of service by hanging decompression threads during specific mount sequences.
- 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-2022-50193?
CVE-2022-50193 is a medium-severity vulnerability in Linux kernel, published on 18 Jun 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:
erofs: wake up all waiters after z_erofs_lzma_head ready
When the user mounts the erofs second times, the decompression thread may hung. The problem happens due to a sequence of steps like the following:
1) Task A called z_erofs_load_lzma_config which obtain all of the node from the z_erofs_lzma_head.
2) At this time, task B called the z_erofs_lzma_decompress and wanted to get a node. But the z_erofs_lzma_head was empty, the Task B had to sleep.
3) Task A release nodes and push nodes into the z_erofs_lzma_head. But task B was still sleeping.
One example report when the hung happens: task:kworker/u3:1 state:D stack:14384 pid: 86 ppid: 2 flags:0x00004000 Workqueue: erofs_unzipd z_erofs_decompressqueue_work Call Trace: <TASK> __schedule+0x281/0x760 schedule+0x49/0xb0 z_erofs_lzma_decompress+0x4bc/0x580 ? cpu_core_flags+0x10/0x10 z_erofs_decompress_pcluster+0x49b/0xba0 ? __update_load_avg_se+0x2b0/0x330 ? __update_load_avg_se+0x2b0/0x330 ? update_load_avg+0x5f/0x690 ? update_load_avg+0x5f/0x690 ? set_next_entity+0xbd/0x110 ? _raw_spin_unlock+0xd/0x20 z_erofs_decompress_queue.isra.0+0x2e/0x50 z_erofs_decompressqueue_work+0x30/0x60 process_one_work+0x1d3/0x3a0 worker_thread+0x45/0x3a0 ? process_one_work+0x3a0/0x3a0 kthread+0xe2/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30 </TASK>
Which versions are affected by CVE-2022-50193?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50193?
Apply the vendor's patch.
Is CVE-2022-50193 being exploited?
There is no known exploitation of CVE-2022-50193 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50193, GHSA-9244-ghq8-mvq4, UBUNTU-CVE-2022-50193.