netdev - Re: [PATCH net-next] ipv6: do not use skb_header_pointer() in icmpv6

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Message-ID: <CAAVpQUBrLm+-5PEkKkYATQMUPtB_MROcByJVrx3Hg26jFPj1SA@mail.gmail.com>
Date: Thu, 5 Feb 2026 20:13:11 -0800
From: Kuniyuki Iwashima <kuniyu@...gle.com>
To: Eric Dumazet <edumazet@...gle.com>
Cc: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>, 
	Paolo Abeni <pabeni@...hat.com>, Simon Horman <horms@...nel.org>, David Ahern <dsahern@...nel.org>, 
	netdev@...r.kernel.org, eric.dumazet@...il.com
Subject: Re: [PATCH net-next] ipv6: do not use skb_header_pointer() in icmpv6_filter()

On Thu, Feb 5, 2026 at 1:19 PM Eric Dumazet <edumazet@...gle.com> wrote:
>
> Prefer pskb_may_pull() to avoid a stack canary in raw6_local_deliver().
>
> Note: skb->head can change, hence we reload ip6h pointer in
> ipv6_raw_deliver()
>
> $ scripts/bloat-o-meter -t vmlinux.old vmlinux.new
> add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-86 (-86)
> Function                                     old     new   delta
> raw6_local_deliver                           780     694     -86
> Total: Before=24889784, After=24889698, chg -0.00%
>
> Signed-off-by: Eric Dumazet <edumazet@...gle.com>

Reviewed-by: Kuniyuki Iwashima <kuniyu@...gle.com>