ocfs2: fix possible use-after-free with AIO

commit 9b171e0c74ca0549d0610990a862dd895870f04a upstream.

Running AIO is pinning inode in memory using file reference. Once AIO
is completed using aio_complete(), file reference is put and inode can
be freed from memory. So we have to be sure that calling aio_complete()
is the last thing we do with the inode.

Signed-off-by: Jan Kara <jack@suse.cz>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/ocfs2/aops.c b/fs/ocfs2/aops.c
index 657743254eb90079666eaab73723de0a1bc4ed51..340bd02839be010a2227ea127e3142bd9a320ecc 100644 (file)
--- a/fs/ocfs2/aops.c
+++ b/fs/ocfs2/aops.c
@@ -593,9 +593,9 @@ static void ocfs2_dio_end_io(struct kiocb *iocb,
        level = ocfs2_iocb_rw_locked_level(iocb);
        ocfs2_rw_unlock(inode, level);
 
+       inode_dio_done(inode);
        if (is_async)
                aio_complete(iocb, ret, 0);
-       inode_dio_done(inode);
 }
 
 /*