From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=217.70.190.124 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794532500; b=12EYGe0oqqAWMLRuArEjQFUn1Tst67f9VK8DSBFSB8V+oEl4iFk6+eNaaE0WRNk1N5ar 2OeRWWnCXLttWDNT/HbbozCK5XQSdrj4jba2yeeDJlIQ2IS3Ooycp+Y0WIBvGNsFamrJ2 FoOlFEeaoRPa5wweHuYTTB2leH+vPhUAxxwuSwAKQE2SxndI6pvZiz7NsPkl4eJXHr5Bz cX/CNpB6YqwbwYTBIk83LsFrs8QflE9gb/LNNSa8lvp47/jCUpTjuB4expTEy9/tFt9n2 A5nNHdjGZEZjNWetfWCa97Ho06jv9VRdbUr1Cw8YDmtDhkS0XM+C+A8voxorhsPpohg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794532500; h=DMARC-Filter:DKIM-Signature:Received:From:To:Cc:Subject:Date: Message-ID:X-Mailer:In-Reply-To:References:MIME-Version: Content-Transfer-Encoding:X-Spam-Status:X-Spam-Checker-Version; bh=zzEsJnJnM1bQXthU4+437vS4Xm/cQAtHw6bJmg1IONE=; b=tVugAzNV5g17WplV4aGHrlafGKb2QlUERxj96Jw3dsUBEzDTZ3qZ6FtfgymQVoV+cJKi dP0hqrp8b9lcqRh5GbT2+COwJ7+lXtkh4GbgsZGt1NOtjGTEo1uYlmlSxPjV/XrAcZqFd FM0UpNnIhdpvNgxePUs3n9JMr+hRLPUFDM3J/EAFHzfMioZyhYQhNMaHh6Zr5jyiPgcWr 0XpQr5jQyKQLLFaIoBN5mIqSkPsrzzS8Be8V+8lqhRGJj2qs5I+PJ7SZ3zhSY/Y8LFIGm Air/Ex3OoK6ve+nwFRulPUeHg1a4D0JXc5gjbdyXD/8opfQTcQpKBrTWbWSjVYg3mfg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none header.from=netfilter.org; spf=pass smtp.mailfrom=netfilter.org; dkim=pass header.d=netfilter.org header.i=@netfilter.org header.a=rsa-sha256 header.s=2025 header.b=S3duZu2R; arc=none smtp.remote-ip=217.70.190.124 Received: from mail.netfilter.org (mail.netfilter.org [217.70.190.124]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 61104606A333; Fri, 13 Nov 2026 01:15:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 61104606A333 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=netfilter.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=netfilter.org header.i=@netfilter.org header.a=rsa-sha256 header.s=2025 header.b=S3duZu2R DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1794532498; bh=zzEsJnJnM1bQXthU4+437vS4Xm/cQAtHw6bJmg1IONE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S3duZu2RNJMgqFlSR5qyfemWOVEJk7CLxGNhx3v4Oeu+x5/yDE0DhjWu+lQakoK1i IkxE28ZVxd4vBY7xVxkGSKDC/6KdjrvS08XA/vrQMJBkXQzklu4CIe3TI87BlOI3vQ JgBPoH1z4an41Usg5FjMXFTG2ggIQHH4NImEdvOQUhmdi2CvP2DMGzJDrWuF8o6OT7 n9ZravCuPxf7lgpNV6UlR/aQJhT5a+8hJY2gNfrnzGMUJH8SPpiIMGm83EB7cui4aP vePNQ4U7tc9kpbqeQVsDUIgXJA9WptdBVOnt5R8YSLYahRgAy1NcTYsMeiwTVskJBn 3SbiwcnmhMkNQ== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 3C5AA6005C; Fri, 13 Nov 2026 02:14:58 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org, pabeni@redhat.com, edumazet@kernel.org, horms@kernel.org, fw@strlen.de, ja@ssi.bg Subject: [PATCH net 02/15] ipv6: update *offset for non-first fragments in ipv6_find_hdr() Date: Fri, 13 Nov 2026 02:14:34 +0100 Message-ID: <20261113011447.2357709-3-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261113011447.2357709-1-pablo@netfilter.org> References: <20261113011447.2357709-1-pablo@netfilter.org> X-Mailing-List: netdev@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Axel Mierczuk The non-first fragment early return is the only successful exit of ipv6_find_hdr() that leaves *offset untouched. IPVS used the initial offset as if it had been updated. For non-first fragments with target < 0, set *offset immediately after the Fragment header, at the start of the fragment payload. Callers must still account for the nonzero fragment offset. A NEXTHDR_FRAGMENT search continues to return the Fragment header's offset. Other target < 0 callers check the returned fragment offset or ignore *offset here. Fixes: b777e0ce7437 ("[NETFILTER]: make ipv6_find_hdr() find transport protocol header") Suggested-by: Julian Anastasov Signed-off-by: Axel Mierczuk Acked-by: Julian Anastasov Signed-off-by: Pablo Neira Ayuso --- net/ipv6/exthdrs_core.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/net/ipv6/exthdrs_core.c b/net/ipv6/exthdrs_core.c index 4a9748338cf4..e27f5b8cc154 100644 --- a/net/ipv6/exthdrs_core.c +++ b/net/ipv6/exthdrs_core.c @@ -179,7 +179,10 @@ EXPORT_SYMBOL_GPL(ipv6_find_tlv); * * Note that non-1st fragment is special case that "the protocol number * of last header" is "next header" field in Fragment header. In this case, - * *offset is meaningless and fragment offset is stored in *fragoff if fragoff + * for target < 0, *offset points immediately after the Fragment header, + * at the start of the fragment payload. Callers must still account for + * the nonzero fragment offset before interpreting the payload. The + * fragment offset is stored in *fragoff if fragoff * isn't NULL. * * if flags is not NULL and it's a fragment, then the frag flag @@ -261,6 +264,7 @@ int ipv6_find_hdr(const struct sk_buff *skb, unsigned int *offset, hp->nexthdr == NEXTHDR_NONE)) { if (fragoff) *fragoff = _frag_off; + *offset = start + sizeof(struct frag_hdr); return hp->nexthdr; } if (!found) -- 2.47.3