CVE-2025-21830

A flaw was found in the Linux kernel's Landlock security module. When a corrupted filesystem (for example, bcachefs) returns a file with an unexpected file type, Landlock logged a warning and allowed access to that file instead of applying its access-control rules, so an unprivileged local user could gain access to a file that Landlock restrictions should have blocked. Red Hat rates this issue as Low impact for the kernel and kernel-rt packages in Red Hat Enterprise Linux 9 and 10 and in Red Hat In-Vehicle OS 1, which are affected. Red Hat Enterprise Linux 6, 7, and 8 are not affected because the Landlock code was introduced upstream in kernel version 5.13 and the vulnerable code is not present in those releases. The fix for the affected streams is deferred: because of the low severity and the unusual preconditions required, it is planned for a future update rather than an immediate erratum, and the residual risk until then is considered low since triggering the flaw requires a corrupted filesystem that returns files with unexpected file types. This Red Hat Low rating is lower than the upstream CVE.org severity of Important (7.3) because Red Hat assesses the practical impact, given the required preconditions, as limited.