diff mbox series

fs: namespace: fix uninitialized variable use

Message ID 20250226081201.1876195-1-arnd@kernel.org (mailing list archive)
State New
Headers show
Series fs: namespace: fix uninitialized variable use | expand

Commit Message

Arnd Bergmann Feb. 26, 2025, 8:11 a.m. UTC 
From: Arnd Bergmann <arnd@arndb.de>

clang correctly notices that the 'uflags' variable initialization
only happens in some cases:

fs/namespace.c:4622:6: error: variable 'uflags' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
 4622 |         if (flags & MOVE_MOUNT_F_EMPTY_PATH)    uflags = AT_EMPTY_PATH;
      |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
fs/namespace.c:4623:48: note: uninitialized use occurs here
 4623 |         from_name = getname_maybe_null(from_pathname, uflags);
      |                                                       ^~~~~~
fs/namespace.c:4622:2: note: remove the 'if' if its condition is always true
 4622 |         if (flags & MOVE_MOUNT_F_EMPTY_PATH)    uflags = AT_EMPTY_PATH;
      |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Fixes: b1e9423d65e3 ("fs: support getname_maybe_null() in move_mount()")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 fs/namespace.c | 2 ++
 1 file changed, 2 insertions(+)

Comments

Christian Brauner Feb. 26, 2025, 8:23 a.m. UTC | #1 
On Wed, 26 Feb 2025 09:11:54 +0100, Arnd Bergmann wrote:
> clang correctly notices that the 'uflags' variable initialization
> only happens in some cases:
> 
> fs/namespace.c:4622:6: error: variable 'uflags' is used uninitialized whenever 'if' condition is false [-Werror,-Wsometimes-uninitialized]
>  4622 |         if (flags & MOVE_MOUNT_F_EMPTY_PATH)    uflags = AT_EMPTY_PATH;
>       |             ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> fs/namespace.c:4623:48: note: uninitialized use occurs here
>  4623 |         from_name = getname_maybe_null(from_pathname, uflags);
>       |                                                       ^~~~~~
> fs/namespace.c:4622:2: note: remove the 'if' if its condition is always true
>  4622 |         if (flags & MOVE_MOUNT_F_EMPTY_PATH)    uflags = AT_EMPTY_PATH;
>       |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> [...]

Applied to the vfs-6.15.mount.namespace branch of the vfs/vfs.git tree.
Patches in the vfs-6.15.mount.namespace branch should appear in linux-next soon.

Please report any outstanding bugs that were missed during review in a
new review to the original patch series allowing us to drop it.

It's encouraged to provide Acked-bys and Reviewed-bys even though the
patch has now been applied. If possible patch trailers will be updated.

Note that commit hashes shown below are subject to change due to rebase,
trailer updates or similar. If in doubt, please check the listed branch.

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git
branch: vfs-6.15.mount.namespace

[1/1] fs: namespace: fix uninitialized variable use
      https://git.kernel.org/vfs/vfs/c/980512134163
diff mbox series

Patch

diff --git a/fs/namespace.c b/fs/namespace.c
index 663bacefddfa..7a531e03cb3c 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -4619,6 +4619,7 @@  SYSCALL_DEFINE5(move_mount,
 	lflags = 0;
 	if (flags & MOVE_MOUNT_F_SYMLINKS)	lflags |= LOOKUP_FOLLOW;
 	if (flags & MOVE_MOUNT_F_AUTOMOUNTS)	lflags |= LOOKUP_AUTOMOUNT;
+	uflags = 0;
 	if (flags & MOVE_MOUNT_F_EMPTY_PATH)	uflags = AT_EMPTY_PATH;
 	from_name = getname_maybe_null(from_pathname, uflags);
 	if (IS_ERR(from_name))
@@ -4627,6 +4628,7 @@  SYSCALL_DEFINE5(move_mount,
 	lflags = 0;
 	if (flags & MOVE_MOUNT_T_SYMLINKS)	lflags |= LOOKUP_FOLLOW;
 	if (flags & MOVE_MOUNT_T_AUTOMOUNTS)	lflags |= LOOKUP_AUTOMOUNT;
+	uflags = 0;
 	if (flags & MOVE_MOUNT_T_EMPTY_PATH)	uflags = AT_EMPTY_PATH;
 	to_name = getname_maybe_null(to_pathname, uflags);
 	if (IS_ERR(to_name))