Commit 52d304eb authored Jan 13, 2015 by NeilBrown Committed by Jeff Layton Jan 13, 2015

locks: fix NULL-deref in generic_delete_lease



commit 0efaa7e8
  locks: generic_delete_lease doesn't need a file_lock at all

moves the call to fl->fl_lmops->lm_change() to a place in the
code where fl might be a non-lease lock.
When that happens, fl_lmops is NULL and an Oops ensures.

So add an extra test to restore correct functioning.

Reported-by: Linda Walsh <suse@tlinx.org>
Link: https://bugzilla.suse.com/show_bug.cgi?id=912569


Cc: stable@vger.kernel.org (v3.18)
Fixes: 0efaa7e8
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@primarydata.com>

parent 971780b7

fs/locks.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -1702,7 +1702,7 @@ static int generic_delete_lease(struct file *filp)
		break;
		}
		trace_generic_delete_lease(inode, fl);
		if (fl)
		if (fl && IS_LEASE(fl))
		error = fl->fl_lmops->lm_change(before, F_UNLCK, &dispose);
		spin_unlock(&inode->i_lock);
		locks_dispose_list(&dispose);