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 <cmaiolino@redhat.com>
Acked-by: Jeff Moyer <jmoyer@redhat.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
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 @@
"(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;
}