fs/stat.c: avoid harmless garbage value problem in vfs_statx_path()

Clang static checker(scan-build) warning:
fs/stat.c:287:21: warning: The left expression of the compound assignment is
an uninitialized value. The computed value will also be garbage.
  287 |                 stat->result_mask |= STATX_MNT_ID_UNIQUE;
      |                 ~~~~~~~~~~~~~~~~~ ^
fs/stat.c:290:21: warning: The left expression of the compound assignment is
an uninitialized value. The computed value will also be garbage.
  290 |                 stat->result_mask |= STATX_MNT_ID;

When vfs_getattr() failed because of security_inode_getattr(), 'stat' is
uninitialized. In this case, there is a harmless garbage problem in
vfs_statx_path(). It's better to return error directly when
vfs_getattr() failed, avoiding garbage value and more clearly.

Signed-off-by: Su Hui <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

Author: Su Hui

fs/stat.c

@@ -281,6 +281,8 @@ static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
 			  u32 request_mask)
 {
 	int error = vfs_getattr(path, stat, request_mask, flags);
+	if (error)
+		return error;
 
 	if (request_mask & STATX_MNT_ID_UNIQUE) {
 		stat->mnt_id = real_mount(path->mnt)->mnt_id_unique;
@@ -302,7 +304,7 @@ static int vfs_statx_path(struct path *path, int flags, struct kstat *stat,
 	if (S_ISBLK(stat->mode))
 		bdev_statx(path, stat, request_mask);
 
-	return error;
+	return 0;
 }
 
 static int vfs_statx_fd(int fd, int flags, struct kstat *stat,