[040/165] VFS: move BUG_ON test for symlink nd->depth after

From: Greg KH
Date: Wed Jun 01 2011 - 04:56:25 EST

2.6.39-stable review patch. If anyone has any objections, please let us know.

current->link_count test
Content-Length: 1009
Lines: 37

From: Erez Zadok <ezk@xxxxxxxxxxxxxxxxx>

commit 1a4022f88d40e1255920b017556092ab926d7f66 upstream.

This solves a serious VFS-level bug in nested_symlink (which was
rewritten from do_follow_link), and follows the order of depth tests
that existed before.

The bug triggers a BUG_ON in fs/namei.c:1381, when running racer with
symlink and rename ops.

Signed-off-by: Erez Zadok <ezk@xxxxxxxxxxxxx>
Acked-by: Miklos Szeredi <mszeredi@xxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

fs/namei.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/namei.c
+++ b/fs/namei.c
@@ -1378,12 +1378,12 @@ static inline int nested_symlink(struct
int res;

- BUG_ON(nd->depth >= MAX_NESTED_LINKS);
if (unlikely(current->link_count >= MAX_NESTED_LINKS)) {
path_put_conditional(path, nd);
return -ELOOP;
+ BUG_ON(nd->depth >= MAX_NESTED_LINKS);


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/