From: Jan Kara Date: Wed, 30 Jan 2013 03:48:17 +0000 (-0500) Subject: ext4: fix possible use-after-free with AIO X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=091e26dfc156aeb3b73bc5c5f277e433ad39331c;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git 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" --- diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 86bf43d6dfcd..07d9defeaf8c 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 5d8c66948e1b..809b31003ecc 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; }