[PATCH 3.18 075/145] nlm: Ensure callback code also checks that the files match

Greg Kroah-Hartman
2017-04-16T11:05:15Z

From: Trond Myklebust <trond.myklebust@primarydata.com>

commit 251af29c320d86071664f02c76f0d063a19fefdf upstream.

It is not sufficient to just check that the lock pids match when
granting a callback, we also need to ensure that we're granting
the callback on the right file.

Reported-by: Pankaj Singh <psingh.ait@gmail.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
include/linux/lockd/lockd.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/include/linux/lockd/lockd.h
+++ b/include/linux/lockd/lockd.h
@@ -351,7 +351,8 @@ static inline int nlm_privileged_request
static inline int nlm_compare_locks(const struct file_lock *fl1,
const struct file_lock *fl2)
{
- return fl1->fl_pid == fl2->fl_pid
+ return file_inode(fl1->fl_file) == file_inode(fl2->fl_file)
+ && fl1->fl_pid == fl2->fl_pid
&& fl1->fl_owner == fl2->fl_owner
&& fl1->fl_start == fl2->fl_start
&& fl1->fl_end == fl2->fl_end