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git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs.git
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Stephen Smalley
28b7260548
When an NFSv4 filesystem exported with security_label is mounted a second time, sget_fc() returns the existing superblock and nfs_get_root() calls security_sb_set_mnt_opts() again on it. Since the superblock is already SB_INITIALIZED, selinux_set_mnt_opts() takes an early exit without setting SECURITY_LSM_NATIVE_LABELS in *set_kern_flags. nfs_get_root() then sees kflags without SECURITY_LSM_NATIVE_LABELS set and clears NFS_CAP_SECURITY_LABEL on the shared nfs_server, silently disabling per-file labeling for both the new and the original mount. Commit3815a245b5("security/selinux: fix SECURITY_LSM_NATIVE_LABELS on reused superblock") fixed the same problem in selinux_sb_clone_mnt_opts(). The reused-superblock path for a plain second mount now goes through sb_set_mnt_opts rather than sb_clone_mnt_opts, so it needs the same treatment: on both SE_SBINITIALIZED early exits, set SECURITY_LSM_NATIVE_LABELS in *set_kern_flags when the superblock was already using SECURITY_FS_USE_NATVE. Cc: [email protected] Closes: https://github.com/SELinuxProject/selinux-kernel/issues/69 Closes: https://github.com/SELinuxProject/selinux-kernel/issues/70 Closes: https://github.com/SELinuxProject/selinux-testsuite/issues/91 Closes: https://github.com/SELinuxProject/selinux-testsuite/issues/92 Fixes:eb9ae68650("SELinux: Add new labeling type native labels") Signed-off-by: Stephen Smalley <[email protected]> Signed-off-by: Paul Moore <[email protected]>