From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qk1-f202.google.com (mail-qk1-f202.google.com [209.85.222.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E3E381F5858 for ; Thu, 5 Feb 2026 21:19:10 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.202 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770326351; cv=none; b=HQuvZ5KO+OoDPAswYIMa7D2XItHnyReR2zd6ce6AU3yuTU6RiRucn72dw4Hmv4Rny9c4hLnYCn9sFzwFa6Tp7jZAhIWjd4StRciIg2gfOYN4MLjQoVCuiETpwXU9lvzArLK4WVnaidrVaZ4UvChMAg3rCEn/eurCkPtyEkH9wdo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1770326351; c=relaxed/simple; bh=J2ko4X9z2DZJzYwQDhffd5vnVXbKe1+M1QXJED1b8PE=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=ODIF7DUHlDWz5sJZWMUTWhXiGfnQy5HJ1alSSyzBsgplBenY7Xs/FgxgDbiITaIWhJcbzcYt7r+ynVN8qUU5LwEUxln5Nj9WI/2Pq7JJIyZa5TEdD9XVHgkJiVPdd3JMPNRLSufXn77I0EpNNy0Jseqo+VGxUykierX4fCepqxk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=cIZ8XITM; arc=none smtp.client-ip=209.85.222.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="cIZ8XITM" Received: by mail-qk1-f202.google.com with SMTP id af79cd13be357-8c70ab7f67fso566856885a.3 for ; Thu, 05 Feb 2026 13:19:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1770326350; x=1770931150; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=7myZG3j2CU7LaFpg4p0P2j0Ms0MQemPHTxkEePH7mSM=; b=cIZ8XITMukmzC4dOws6GoA0Zy71DrahOb95kuSjp17qm6PZWebTztxqZ1iKbEHnY5I FPE13G89pO+Pfx2NYBbHpsGh/+/VOXZ2R4s1zSuTZQQF/RKfkSagTPOvHlYaZw1+s/pa u7m+3uSX/dcVoYyaxv/RGp9s0h7cysirH8RbfYXTz5c0efyBFv8zWTnu9GXg+p6OgZCU XvgloKqSvg4wfxmQ5btfzP2R577P82z028pbDTO5ssey5YVarzYyVP28cHFqTd9lqLj1 yk6ciAX98khyDBIbuQHG3eoxO9SVsu76Ly8dJloPZWrW4gSXRSVtXaTD7vpEHBsUXjIf 2NJA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1770326350; x=1770931150; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=7myZG3j2CU7LaFpg4p0P2j0Ms0MQemPHTxkEePH7mSM=; b=U5aMZ8qzgA9EvvPTyHqfqvyapoOsSeDLejs7hlqLQeT7rogHN6PhvUTvGX5KznMMeJ EcoaVELknhpGxjBp+c8oYa5O9Hgu+ZY0rZiOU7WZzCfhv8e21RJdKw4FR6PvMVWMFuRK HyyLDxKa1ADsu3HNu4lVwewzei/JTgMBn+QDn7Spue2uZ1I36Qx6DevuqvZ/lQmcKgaj tHIYPTn+Ftp/nhx15bgLmpAlsiU0YpGG35vh3k8s/mAc1+oY+aRjbjgj1f1b5yXmR57F CJhDUaWr7CjPNUqFgy0u5gYgALabTtoDsvvp+Kz7NI8GAKMtZqVNVY/iNXjpk0kolezD QyHQ== X-Forwarded-Encrypted: i=1; AJvYcCU5E2kWCeKmcowQhVowThJZ4fzmCsOendQDYno74o2WLW7GbbSJSKnebmpIdHT1bELX3JSN2kk=@vger.kernel.org X-Gm-Message-State: AOJu0YwyxoLnQjT2YjrQE0UykRvZGqkiJT8q68TKffr87UgGH8xUVcm7 FfPH2tiSOmviTAUsa98/30ctTX1pRCSFV9rYCFjgh+vxh19uR7WM+aBr7eyIAE3DziY5VdphatM Bsukf/D2AUPovWg== X-Received: from qkbbl7.prod.google.com ([2002:a05:620a:1a87:b0:8b2:e8b8:3d8a]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:620a:3942:b0:8ca:4438:b8ef with SMTP id af79cd13be357-8caf16ec4f4mr66153085a.69.1770326349893; Thu, 05 Feb 2026 13:19:09 -0800 (PST) Date: Thu, 5 Feb 2026 21:19:09 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.53.0.rc2.204.g2597b5adb4-goog Message-ID: <20260205211909.4115285-1-edumazet@google.com> Subject: [PATCH net-next] ipv6: do not use skb_header_pointer() in icmpv6_filter() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: Simon Horman , David Ahern , Kuniyuki Iwashima , netdev@vger.kernel.org, eric.dumazet@gmail.com, Eric Dumazet Content-Type: text/plain; charset="UTF-8" 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 --- net/ipv6/raw.c | 32 ++++++++++++++++---------------- 1 file changed, 16 insertions(+), 16 deletions(-) diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index ee6beba03e9b498c8ea5b9e5834e26251f81e958..27a2680591684eb2cad011e63cdaf396e79c0d77 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -90,23 +90,24 @@ EXPORT_SYMBOL_GPL(raw_v6_match); * 0 - deliver * 1 - block */ -static int icmpv6_filter(const struct sock *sk, const struct sk_buff *skb) +static int icmpv6_filter(const struct sock *sk, struct sk_buff *skb) { - struct icmp6hdr _hdr; const struct icmp6hdr *hdr; + const __u32 *data; + unsigned int type; /* We require only the four bytes of the ICMPv6 header, not any * additional bytes of message body in "struct icmp6hdr". */ - hdr = skb_header_pointer(skb, skb_transport_offset(skb), - ICMPV6_HDRLEN, &_hdr); - if (hdr) { - const __u32 *data = &raw6_sk(sk)->filter.data[0]; - unsigned int type = hdr->icmp6_type; + if (!pskb_may_pull(skb, ICMPV6_HDRLEN)) + return 1; - return (data[type >> 5] & (1U << (type & 31))) != 0; - } - return 1; + hdr = (struct icmp6hdr *)skb->data; + type = hdr->icmp6_type; + + data = &raw6_sk(sk)->filter.data[0]; + + return (data[type >> 5] & (1U << (type & 31))) != 0; } #if IS_ENABLED(CONFIG_IPV6_MIP6) @@ -141,15 +142,13 @@ EXPORT_SYMBOL(rawv6_mh_filter_unregister); static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr) { struct net *net = dev_net(skb->dev); - const struct in6_addr *saddr; - const struct in6_addr *daddr; + const struct ipv6hdr *ip6h; struct hlist_head *hlist; - struct sock *sk; bool delivered = false; + struct sock *sk; __u8 hash; - saddr = &ipv6_hdr(skb)->saddr; - daddr = saddr + 1; + ip6h = ipv6_hdr(skb); hash = raw_hashfunc(net, nexthdr); hlist = &raw_v6_hashinfo.ht[hash]; @@ -157,7 +156,7 @@ static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr) sk_for_each_rcu(sk, hlist) { int filtered; - if (!raw_v6_match(net, sk, nexthdr, daddr, saddr, + if (!raw_v6_match(net, sk, nexthdr, &ip6h->daddr, &ip6h->saddr, inet6_iif(skb), inet6_sdif(skb))) continue; @@ -171,6 +170,7 @@ static bool ipv6_raw_deliver(struct sk_buff *skb, int nexthdr) switch (nexthdr) { case IPPROTO_ICMPV6: filtered = icmpv6_filter(sk, skb); + ip6h = ipv6_hdr(skb); break; #if IS_ENABLED(CONFIG_IPV6_MIP6) -- 2.53.0.rc2.204.g2597b5adb4-goog