[ 12/33] xfs: Fix possible use-after-free with AIO

[Greg Kroah-Hartman]

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Kara <jack at suse.cz>

commit 4b05d09c18d9aa62d2e7fb4b057f54e5a38963f5 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 at suse.cz>
CC: xfs at oss.sgi.com
CC: Ben Myers <bpm at sgi.com>
Reviewed-by: Ben Myers <bpm at sgi.com>
Signed-off-by: Ben Myers <bpm at sgi.com>
Signed-off-by: Greg Kroah-Hartman <gregkh at linuxfoundation.org>

---
 fs/xfs/xfs_aops.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -89,11 +89,11 @@ 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);