From: Jan Kara Subject: [PATCH 1/4] ext4: Fix possible use-after-free with AIO Date: Wed, 30 Jan 2013 00:27:58 +0100 Message-ID: <1359502081-20240-2-git-send-email-jack@suse.cz> References: <1359502081-20240-1-git-send-email-jack@suse.cz> Cc: linux-fsdevel@vger.kernel.org, xfs@oss.sgi.com, linux-ext4@vger.kernel.org, ocfs2-devel@oss.oracle.com, Jan Kara , "Theodore Ts'o" , stable@vger.kernel.org To: Al Viro Return-path: In-Reply-To: <1359502081-20240-1-git-send-email-jack@suse.cz> Sender: stable-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 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: linux-ext4@vger.kernel.org CC: "Theodore Ts'o" CC: stable@vger.kernel.org Reviewed-by: Carlos Maiolino Acked-by: Jeff Moyer Signed-off-by: Jan Kara --- fs/ext4/inode.c | 2 +- fs/ext4/page-io.c | 9 ++++----- 2 files changed, 5 insertions(+), 6 deletions(-) diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index cbfe13b..ba06638 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2977,9 +2977,9 @@ static void ext4_end_io_dio(struct kiocb *iocb, loff_t offset, if (!(io_end->flag & EXT4_IO_END_UNWRITTEN)) { ext4_free_io_end(io_end); out: + inode_dio_done(inode); if (is_async) aio_complete(iocb, ret, 0); - inode_dio_done(inode); return; } diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c index 0016fbc..b42d04f 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -103,14 +103,13 @@ static int ext4_end_io(ext4_io_end_t *io) "(inode %lu, offset %llu, size %zd, error %d)", inode->i_ino, offset, size, ret); } - if (io->iocb) - aio_complete(io->iocb, io->result, 0); - - if (io->flag & EXT4_IO_END_DIRECT) - inode_dio_done(inode); /* Wake up anyone waiting on unwritten extent conversion */ if (atomic_dec_and_test(&EXT4_I(inode)->i_unwritten)) wake_up_all(ext4_ioend_wq(inode)); + if (io->flag & EXT4_IO_END_DIRECT) + inode_dio_done(inode); + if (io->iocb) + aio_complete(io->iocb, io->result, 0); return ret; } -- 1.7.1