TOMOYO: Fix pathname handling of disconnected paths.
Current tomoyo_realpath_from_path() implementation returns strange pathname
when calculating pathname of a file which belongs to lazy unmounted tree.
Use local pathname rather than strange absolute pathname in that case.
Also, this patch fixes a regression by commit 02125a82 "fix apparmor
dereferencing potentially freed dentry, sanitize __d_path() API".
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c
index 36fa7c9..d9f3ced 100644
--- a/security/tomoyo/realpath.c
+++ b/security/tomoyo/realpath.c
@@ -293,8 +293,16 @@
pos = tomoyo_get_local_path(path->dentry, buf,
buf_len - 1);
/* Get absolute name for the rest. */
- else
+ else {
pos = tomoyo_get_absolute_path(path, buf, buf_len - 1);
+ /*
+ * Fall back to local name if absolute name is not
+ * available.
+ */
+ if (pos == ERR_PTR(-EINVAL))
+ pos = tomoyo_get_local_path(path->dentry, buf,
+ buf_len - 1);
+ }
encode:
if (IS_ERR(pos))
continue;
