Linux Kernel up to 5.18.17/5.19.1 erofs z_erofs_lzma_head state issue

Summaryinfo

A vulnerability identified as problematic has been detected in Linux Kernel up to 5.18.17/5.19.1. Impacted is the function z_erofs_lzma_head of the component erofs. The manipulation leads to state issue. This vulnerability is referenced as CVE-2022-50193. No exploit is available. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as problematic, has been found in Linux Kernel up to 5.18.17/5.19.1. This issue affects the function z_erofs_lzma_head of the component erofs. The manipulation with an unknown input leads to a state issue vulnerability. Using CWE to declare the problem leads to CWE-371. The impact remains unknown. The summary by CVE is:

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>

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2022-50193 since 06/18/2025. The exploitation is known to be difficult. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 12/01/2025).

Upgrading to version 5.18.18 or 5.19.2 eliminates this vulnerability. Applying the patch 2478e36ec437a27f8a05bea9e4269a68c554e21f/96aa2a6a89618d850ef082e4268007e840c28769/2df7c4bd7c1d2bc5ece5e9ed19dbd386810c2a65 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2025-1350). Be aware that VulDB is the high quality source for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• Open Source Linux Kernel
• RESF Rocky Linux
• Dell Avamar
• Dell NetWorker
• Dell Secure Connect Gateway
• IBM QRadar SIEM

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.18.0
• 5.18.1
• 5.18.2
• 5.18.3
• 5.18.4
• 5.18.5
• 5.18.6
• 5.18.7
• 5.18.8
• 5.18.9
• 5.18.10
• 5.18.11
• 5.18.12
• 5.18.13
• 5.18.14
• 5.18.15
• 5.18.16
• 5.18.17
• 5.19.0
• 5.19.1

License

• open-source

Website

• Vendor: https://www.kernel.org/

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CPE 2.2info

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Entryinfo

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