[PATCH V2 next] keys/dns: fix slab-out-of-bounds in dns_resolver_preparse

[Simon Horman]

On Thu, Dec 14, 2023 at 10:46:10PM +0800, Edward Adam Davis wrote:
> bin will be forcibly converted to "struct dns_server_list_v1_header *", so it 
> is necessary to compare datalen with sizeof(*v1).
> 
> Fixes: b946001d3bb1 ("keys, dns: Allow key types (eg. DNS) to be reclaimed immediately on expiry")
> Reported-and-tested-by: syzbot+94bbb75204a05da3d89f at syzkaller.appspotmail.com
> Signed-off-by: Edward Adam Davis <eadavis at qq.com>
> ---
>  net/dns_resolver/dns_key.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

This change looks correct to me.
And I agree that it addresses a problem introduced by the cited commit.
I also note that it depends on the cited commit, which is not present in net.

Reviewed-by: Simon Horman <horms at kernel.org>