[PATCH 4.4 318/342] do_last(): ELOOP failure exit should be done after leaving RCU mode

From: Greg Kroah-Hartman
Date: Tue Mar 01 2016 - 18:58:56 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

commit 5129fa482b16615fd4464d2f5d23acb1b7056c66 upstream.

... or we risk seeing a bogus value of d_is_symlink() there.

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/namei.c | 9 ++++-----
1 file changed, 4 insertions(+), 5 deletions(-)

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -3149,11 +3149,6 @@ finish_lookup:
if (unlikely(error))
return error;

- if (unlikely(d_is_symlink(path.dentry)) && !(open_flag & O_PATH)) {
- path_to_nameidata(&path, nd);
- return -ELOOP;
- }
-
if ((nd->flags & LOOKUP_RCU) || nd->path.mnt != path.mnt) {
path_to_nameidata(&path, nd);
} else {
@@ -3172,6 +3167,10 @@ finish_open:
return error;
}
audit_inode(nd->name, nd->path.dentry, 0);
+ if (unlikely(d_is_symlink(nd->path.dentry)) && !(open_flag & O_PATH)) {
+ error = -ELOOP;
+ goto out;
+ }
error = -EISDIR;
if ((open_flag & O_CREAT) && d_is_dir(nd->path.dentry))
goto out;