Patchwork [115/139] fs: Fix possible use-after-free with AIO

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Submitter Luis Henriques
Date Feb. 28, 2013, 2:44 p.m.
Message ID <1362062689-2567-116-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/224084/
State New
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Luis Henriques - Feb. 28, 2013, 2:44 p.m.
3.5.7.7 -stable review patch.  If anyone has any objections, please let me know.

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

From: Jan Kara <jack@suse.cz>

commit 54c807e71d5ac59dee56c685f2b66e27cd54c475 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.

CC: Christoph Hellwig <hch@infradead.org>
CC: Jens Axboe <axboe@kernel.dk>
CC: Jeff Moyer <jmoyer@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 fs/direct-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Patch

diff --git a/fs/direct-io.c b/fs/direct-io.c
index 0c85fae..84466cb 100644
--- a/fs/direct-io.c
+++ b/fs/direct-io.c
@@ -261,9 +261,9 @@  static ssize_t dio_complete(struct dio *dio, loff_t offset, ssize_t ret, bool is
 		dio->end_io(dio->iocb, offset, transferred,
 			    dio->private, ret, is_async);
 	} else {
+		inode_dio_done(dio->inode);
 		if (is_async)
 			aio_complete(dio->iocb, ret, 0);
-		inode_dio_done(dio->inode);
 	}
 
 	return ret;