Description
The X-mount.subdir option uses a detached-tree fast path on Linux 6.15 and later and passes the configured subdirectory to open_tree() with AT_SYMLINK_NOFOLLOW. That flag does not stop intermediate symlink traversal or keep resolution inside the newly mounted filesystem. A local unprivileged user with an fstab-authorized X-mount.subdir entry can attach a host path at the intended mountpoint.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Red Hat Red Hat Hardened Images
Default version status: affected
2.42.2-3.4.hum1 to < *unaffected
Red Hat Red Hat Enterprise Linux 10
Default version status: unaffected
Red Hat Red Hat Enterprise Linux 7
Default version status: unaffected
Red Hat Red Hat Enterprise Linux 8
Default version status: unaffected
Red Hat Red Hat Enterprise Linux 9
Default version status: unaffected
Red Hat Red Hat Enterprise Linux 9
Default version status: unaffected
Red Hat Red Hat Enterprise Linux 9
Default version status: unaffected
Red Hat Red Hat OpenShift Container Platform 4
Default version status: unaffected
Red Hat Red Hat OpenShift Container Platform 4
Default version status: unaffected