ovl: don't allow datadir only
In the Linux kernel, the following vulnerability has been resolved: ovl: don't allow datadir only In theory overlayfs could support upper layer directly referring to a data layer, but there's no current use case for this. Originally, when data-only layers were introduced, this wasn't allowed, only introduced by the "datadir+" feature, but without actually handling this case, resulting in an Oops. Fix by disallowing datadir without lowerdir.
02 / AFFECTED SOFTWARE
Affected packages
65 explicit affected versions
04 / EVIDENCE
Source records
In the Linux kernel, the following vulnerability has been resolved: ovl: don't allow datadir only In theory overlayfs could support upper layer directly referring to a data layer, but there's no current use case for this. Originally, when data-only layers were introduced, this wasn't allowed, only introduced by the "datadir+" feature, but without actually handling this case, resulting in an Oops. Fix by disallowing datadir without lowerdir.
05 / REFERENCES
Further evidence
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/0874b629f65320778e7e3e206177770666d9db18
- https://git.kernel.org/stable/c/21d2ffb0e9838a175064c22f3a9de97d1f56f27d
- https://git.kernel.org/stable/c/b9e3579213ba648fa23f780e8d53e99011c62331
- https://git.kernel.org/stable/c/eb3a04a8516ee9b5174379306f94279fc90424c4
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/37xxx/CVE-2025-37863.json
- https://nvd.nist.gov/vuln/detail/CVE-2025-37863