| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.4 317/342] should_follow_link(): validate ->d_seq after having decided to follow | Date | Tue, 01 Mar 2016 23:55:30 +0000 |
| |
4.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Al Viro <viro@zeniv.linux.org.uk>
commit a7f775428b8f5808815c0e3004020cedb94cbe3b upstream.
... otherwise d_is_symlink() above might have nothing to do with the inode value we've got.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/namei.c | 5 +++++ 1 file changed, 5 insertions(+)
--- a/fs/namei.c +++ b/fs/namei.c @@ -1711,6 +1711,11 @@ static inline int should_follow_link(str return 0; if (!follow) return 0; + /* make sure that d_is_symlink above matches inode */ + if (nd->flags & LOOKUP_RCU) { + if (read_seqcount_retry(&link->dentry->d_seq, seq)) + return -ECHILD; + } return pick_link(nd, link, inode, seq); }
|