diff options
| author | Christian Brauner <brauner@kernel.org> | 2025-04-09 10:00:23 +0200 |
|---|---|---|
| committer | Christian Brauner <brauner@kernel.org> | 2025-04-11 15:24:29 +0200 |
| commit | d43dbf7322a356733b3e3a997cad51dce174d83c (patch) | |
| tree | 92742a40ff28543b52ed1c0a803fd9e15fbea2b7 /fs | |
| parent | b2b4483b5d05026218127fc8f38c69adf69c235b (diff) | |
mount: ensure we don't pointlessly walk the mount tree
This logic got broken recently. Add it back.
Fixes: 474f7825d533 ("fs: add copy_mount_setattr() helper")
Link: https://lore.kernel.org/20250409-sektflaschen-gecko-27c021fbd222@brauner
Tested-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/namespace.c | 30 |
1 files changed, 18 insertions, 12 deletions
diff --git a/fs/namespace.c b/fs/namespace.c index 14935a0500a2..1eb76d6312de 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -5189,8 +5189,8 @@ static void finish_mount_kattr(struct mount_kattr *kattr) mnt_idmap_put(kattr->mnt_idmap); } -static int copy_mount_setattr(struct mount_attr __user *uattr, size_t usize, - struct mount_kattr *kattr) +static int wants_mount_setattr(struct mount_attr __user *uattr, size_t usize, + struct mount_kattr *kattr) { int ret; struct mount_attr attr; @@ -5213,9 +5213,13 @@ static int copy_mount_setattr(struct mount_attr __user *uattr, size_t usize, if (attr.attr_set == 0 && attr.attr_clr == 0 && attr.propagation == 0) - return 0; + return 0; /* Tell caller to not bother. */ + + ret = build_mount_kattr(&attr, usize, kattr); + if (ret < 0) + return ret; - return build_mount_kattr(&attr, usize, kattr); + return 1; } SYSCALL_DEFINE5(mount_setattr, int, dfd, const char __user *, path, @@ -5247,8 +5251,8 @@ SYSCALL_DEFINE5(mount_setattr, int, dfd, const char __user *, path, if (flags & AT_RECURSIVE) kattr.kflags |= MOUNT_KATTR_RECURSE; - err = copy_mount_setattr(uattr, usize, &kattr); - if (err) + err = wants_mount_setattr(uattr, usize, &kattr); + if (err <= 0) return err; err = user_path_at(dfd, path, kattr.lookup_flags, &target); @@ -5282,15 +5286,17 @@ SYSCALL_DEFINE5(open_tree_attr, int, dfd, const char __user *, filename, if (flags & AT_RECURSIVE) kattr.kflags |= MOUNT_KATTR_RECURSE; - ret = copy_mount_setattr(uattr, usize, &kattr); - if (ret) + ret = wants_mount_setattr(uattr, usize, &kattr); + if (ret < 0) return ret; - ret = do_mount_setattr(&file->f_path, &kattr); - if (ret) - return ret; + if (ret) { + ret = do_mount_setattr(&file->f_path, &kattr); + if (ret) + return ret; - finish_mount_kattr(&kattr); + finish_mount_kattr(&kattr); + } } fd = get_unused_fd_flags(flags & O_CLOEXEC); |