diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2025-03-18 12:29:21 -0400 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-03-19 09:19:04 +0100 |
| commit | e1ff7aa34dec7e650159fd7ca8ec6af7cc428d9f (patch) | |
| tree | e8f730c9dd1df1666220a97858716004d244d3df | |
| parent | e1c24b52adb22136fa6f4025daf841384a6d0d1e (diff) | |
umount: Allow superblock owners to force umount
Loosen the permission check on forced umount to allow users holding
CAP_SYS_ADMIN privileges in namespaces that are privileged with respect
to the userns that originally mounted the filesystem.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Link: https://lore.kernel.org/r/12f212d4ef983714d065a6bb372fbb378753bf4c.1742315194.git.trond.myklebust@hammerspace.com
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
| -rw-r--r-- | fs/namespace.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 01fb1074c4c9..57c14af6092a 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2105,6 +2105,7 @@ static void warn_mandlock(void) static int can_umount(const struct path *path, int flags) { struct mount *mnt = real_mount(path->mnt); + struct super_block *sb = path->dentry->d_sb; if (!may_mount()) return -EPERM; @@ -2114,7 +2115,7 @@ static int can_umount(const struct path *path, int flags) return -EINVAL; if (mnt->mnt.mnt_flags & MNT_LOCKED) /* Check optimistically */ return -EINVAL; - if (flags & MNT_FORCE && !capable(CAP_SYS_ADMIN)) + if (flags & MNT_FORCE && !ns_capable(sb->s_user_ns, CAP_SYS_ADMIN)) return -EPERM; return 0; } |