From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Carlos Maiolino , Jeff Moyer , Jan Kara , "Theodore Tso" , Ben Hutchings , Rui Xiang Subject: [PATCH 3.4 62/99] ext4: fix possible use-after-free with AIO Date: Fri, 7 Mar 2014 17:07:58 -0800 Message-Id: <20140308010613.585618263@linuxfoundation.org> In-Reply-To: <20140308010611.468206150@linuxfoundation.org> References: <20140308010611.468206150@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 091e26dfc156aeb3b73bc5c5f277e433ad39331c 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. Reviewed-by: Carlos Maiolino Acked-by: Jeff Moyer Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" [bwh: Backported to 3.2: adjust context] Signed-off-by: Ben Hutchings Cc: Rui Xiang Signed-off-by: Greg Kroah-Hartman --- fs/ext4/inode.c | 2 +- fs/ext4/page-io.c | 9 ++++----- 2 files changed, 5 insertions(+), 6 deletions(-) --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2800,9 +2800,9 @@ static void ext4_end_io_dio(struct kiocb 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; } --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -107,14 +107,13 @@ int ext4_end_io_nolock(ext4_io_end_t *io 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_aiodio_unwritten)) wake_up_all(ext4_ioend_wq(io->inode)); + if (io->flag & EXT4_IO_END_DIRECT) + inode_dio_done(inode); + if (io->iocb) + aio_complete(io->iocb, io->result, 0); return ret; }