Re: [syzbot] [net?] kernel BUG in __nla_validate_parse

[Jakub Kicinski]

On Sat, 9 Mar 2024 16:25:18 +0100 Eric Dumazet wrote:
> On Sat, Mar 9, 2024 at 4:13 PM syzbot
> > ..
> Petr, can you take a look ?
> 
> Thanks !
> 
> 
> commit 2118f9390d83cf942de8b34faf3d35b54f9f4eee
> Author: Petr Machata <petrm@xxxxxxxxxx>
> Date:   Wed Mar 6 13:49:15 2024 +0100
> 
>     net: nexthop: Adjust netlink policy parsing for a new attribute

Yeah

+static const struct nla_policy rtm_nh_policy_del[] = {
+       [NHA_ID]                = { .type = NLA_U32 },
+};

+       err = nlmsg_parse(nlh, sizeof(struct nhmsg), tb, NHA_MAX,
+                         rtm_nh_policy_del, extack);

The policy size must be >= max_attr (NHA_MAX).