What’s Vulnerable › Vulnerabilities
CVE-2026-72025: s390/monwriter: Reject buffer reuse with different data length
- Severity: unknown
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-15 · updated 2026-08-18
Description
In the Linux kernel, the following vulnerability has been resolved: s390/monwriter: Reject buffer reuse with different data length When data buffers are reused, e.g. for interval sample records, the first record determines the data length, and the size of the buffer for user copy. Current monwriter code does not check if the data length was changed for subsequent records, which also would never happen for valid user programs. However, a malicious user could change the data length, resulting in out of bounds user copy to the kernel buffer, and memory corruption. By default, the monwriter misc device is created with root-only permissions, so practical impact is typically low. Fix this by checking for changed data length and rejecting such records.
Affected products
- Linux kernel: 2.6.19 — fixed in 7.2
How to fix
Upgrade to a fixed version: Linux kernel 7.2. Check the vendor advisory for mitigations.
References
- https://git.kernel.org/stable/c/01f3ce411711c2c919598ea25320a5a48f71edbc
- https://git.kernel.org/stable/c/036bc5661060702e798d215e81bb46da530965b3
- https://git.kernel.org/stable/c/096dff1247037d329c04b3a5be0ecdfb1c5c7ac6
- https://git.kernel.org/stable/c/2995ccec260caa9e85b3301a4aba1e66ed80ad74
- https://git.kernel.org/stable/c/759d91378203ea35fa9bca6726dcf0010de081fb
- https://git.kernel.org/stable/c/ae5347f3db1782c6118f6cc0d9fd8b1d43397db3
- https://git.kernel.org/stable/c/d39cf4a6d721b1ae21eb53bbf3e8cd984253d7ab
- https://git.kernel.org/stable/c/f0745496f7c171271cafd9457df3b914a483ddeb
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