Re: [PATCH] crypto: fix uninit-value in af_alg_free_resources

[David Howells <dhowells@redhat.com>]

Pavel Skripkin <paskripkin@gmail.com> wrote:

> Syzbot was able to trigger use of uninitialized memory in
> af_alg_free_resources.
> 
> Bug is caused by missing initialization of rsgl->sgl.need_unpin before
> adding to rsgl_list. Then in case of extract_iter_to_sg() failure, rsgl
> is left with uninitialized need_unpin which is read during clean up

Looks feasible :-).

> +		rsgl->sgl.need_unpin = 0;
> +

The blank line isn't really necessary and it's a bool, so can you use 'false'
rather than '0'?

Alternatively, it might be better to move:

		rsgl->sgl.need_unpin =
			iov_iter_extract_will_pin(&msg->msg_iter);

up instead.

David