From: Carlos Maiolino Subject: Re: [PATCH 1/4] ext4: Fix possible use-after-free with AIO Date: Wed, 23 Jan 2013 08:18:10 -0500 Message-ID: <20130123131810.GC1423@localhost.localdomain> References: <1358945780-23661-1-git-send-email-jack@suse.cz> <1358945780-23661-2-git-send-email-jack@suse.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, tytso@mit.edu, bpm@sgi.com, jlbec@evilplan.org, linux-ext4@vger.kernel.org, stable@vger.kernel.org To: Jan Kara Return-path: Content-Disposition: inline In-Reply-To: <1358945780-23661-2-git-send-email-jack@suse.cz> Sender: stable-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org Looks Good, Reviewed-by: Carlos Maiolino On Wed, Jan 23, 2013 at 01:56:17PM +0100, Jan Kara wrote: > 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 > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- Carlos