Unprivileged system crash via unnotified page dirtying
Published Feb 26, 2025 · Updated May 11, 2026
Reachable assertion in the ext4 subsystem in Linux allows local users to crash the system through process_vm_writev. The remote GUP paths in mm/gup.c dirty file-backed pages without first invoking page_mkwrite, leaving ext4 writeback to hit a BUG assertion. Any local user able to invoke process_vm_writev against a mapping on ext4 can trigger a kernel crash, with potential loss of dirty page data.
Summary
What happened
Reachable assertion in the ext4 subsystem in Linux allows local users to crash the system through process_vm_writev. The remote GUP paths in mm/gup.c dirty file-backed pages without first invoking page_mkwrite, leaving ext4 writeback to hit a BUG assertion. Any local user able to invoke process_vm_writev against a mapping on ext4 can trigger a kernel crash, with potential loss of dirty page data.
The record
- CVE
- CVE-2022-49171
- Published
- Feb 26, 2025
- Updated
- May 11, 2026
- Vendor
- The Linux Kernel Organization
- Product
- Linux
- Classifications
- CWE-617, T1499
- Attack vector
- local
- Privileges
- authenticated
Timeline
How it unfolded
- Feb 26, 2025CVE publishedPublication date reported by the CVE source.
- May 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=2.6.37
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <0d3a6926f7e8be3c897fa46216ce13b119a9f56a
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <330d0e44fc5a47c27df958ecdd4693a3cb1d8b81
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <343117559ef41e992e326f7a92da1a8f254dfa8c
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <5a016c053f426a73752c3b41b60b497b58694d48
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <5db60e76edf5680ff1f3a7221036fc44b308f146
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <677c9d30e8487bee6c8e3b034070319d98f6e203
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <a0856764dc1276ad2dc7891288c2e9246bf11a37
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <cc5095747edfb054ca2068d01af20be3fcc3634f
- Affected versionversion=a42afc5f56f319107e987aa6adf2f65d93d527c7 <d666dfaa571465a19f014534a214c255ea33f301
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Public exploit references
- Syzkaller process_vm_writev reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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