xfs: Fix possible use-after-free with AIO

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.

CC: xfs@oss.sgi.com
CC: Ben Myers <bpm@sgi.com>
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 4111a40ebe1..5f707e53717 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -86,11 +86,11 @@ xfs_destroy_ioend(
         }
 
         if (ioend->io_iocb) {
+                inode_dio_done(ioend->io_inode);
                 if (ioend->io_isasync) {
                         aio_complete(ioend->io_iocb, ioend->io_error ?
                                         ioend->io_error : ioend->io_result, 0);
                 }
-                inode_dio_done(ioend->io_inode);
         }
 
         mempool_free(ioend, xfs_ioend_pool);