From 091e26dfc156aeb3b73bc5c5f277e433ad39331c Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 29 Jan 2013 22:48:17 -0500 Subject: [PATCH] ext4: fix possible use-after-free with AIO 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: stable@vger.kernel.org Reviewed-by: Carlos Maiolino Acked-by: Jeff Moyer Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" --- 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 86bf43d..07d9def 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2850,9 +2850,9 @@ 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 5d8c669..809b310 100644 --- a/fs/ext4/page-io.c +++ b/fs/ext4/page-io.c @@ -102,14 +102,13 @@ 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; } -- 2.7.4