diff options
| author | Trond Myklebust <trond.myklebust@hammerspace.com> | 2025-03-18 12:29:21 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2025-04-20 10:22:22 +0200 |
| commit | 5fc7e08dcebf3abb1f19ee33c993dd768bc8b27a (patch) | |
| tree | 50e1c371850e1535003d94257763a022dc7819a0 | |
| parent | 82a2b3f5f9a84b87edd26810799818f70b394b8c (diff) | |
umount: Allow superblock owners to force umount
[ Upstream commit e1ff7aa34dec7e650159fd7ca8ec6af7cc428d9f ]
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>
Signed-off-by: Sasha Levin <sashal@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 8f1000f9f3df..d401486fe95d 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -2026,6 +2026,7 @@ 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; @@ -2035,7 +2036,7 @@ 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; } |