From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1BB7F5383E2; Wed, 23 Sep 2026 14:48:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174899; cv=none; b=YzDDV11Qbpvvp6GHh/044X5qZFx6E/ualRVaZLO4peakprgZ9OuTCWb0/VSkaF6SUuIv+DkHQON4P9qhrM4rvTmCJ4OGZxiuzWtVFg7Orcfw56yv2kz5FE4HKPBLy0Vi5oUiAgAg4YOD0Ocu13G1PSfs/xxQ0WmQ3ua6/LBgM5E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174899; c=relaxed/simple; bh=cBV90XD6f1qhXmifnCrG2hXRExa0Y8drBsmxzzFKWL8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZpIk0UJJxzgV87tteOd7N5pIAows/RdVFsAeTPSoIp/NuN1j/PQF6Au3siU7HN1OHfujJ6zJiXvL2ByMF3XP9KWwC2cLuWJqmj5i4HbLCsqZw9rhSF9Nxqgrv+9381ESzKAHQSGZfr/fvkV5Cc4iF2trWzbvth0Ki03fj5hVpOc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=fWLLMJEH; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="fWLLMJEH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66A791F000FF; Wed, 23 Sep 2026 14:48:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174898; bh=TMQ2OlCrJSY74kGE4IJJDYwTk4uDygk2SAQNQTANSPQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=fWLLMJEHEz4EvE2ich3hlRMCKUxntmg0UAdfoEa4BWcfWeln3RirJ35n1VONo+JMx o4BRbU6WGfy52qefU5ioWG6YPlVYyhICTnWNIh+F0Fs8531tCnmWRXk8zL+xV9fx97 zAPSroy7iqdYmq0SdZWnuYPuVxpKuunEs6rmQzxE= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Vega , Zhiling Zou , Steffen Klassert Subject: [PATCH 6.18 242/398] ipv6: xfrm: use full sockets in local error paths Date: Wed, 23 Sep 2026 16:05:16 +0200 Message-ID: <20260923140649.687481334@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Zhiling Zou commit 6973a21ee73c5567f883813c8ef414774b45892f upstream. xfrm6_local_rxpmtu() and xfrm6_local_error() dereference skb->sk as if it always pointed at a full IPv6 socket. That is not guaranteed. TCP SYN-ACK skbs can be owned by a TCP_NEW_SYN_RECV request_sock while the output path itself is driven by the full listener. If rerouting selects an IPv6 XFRM tunnel route with a lower MTU, the local PMTU/error handling path can reach these callbacks with that mini-socket still attached to the skb. The callbacks then miscast the request socket as a full inet/IPv6 socket and can read beyond the request_sock allocation when they access inet_sock or ipv6_pinfo state. Resolve the owner with skb_to_full_sk() in both callbacks and bail out when no full socket is attached. This matches the surrounding XFRM IPv6 PMTU/error logic, which already reasons about full sockets with skb_to_full_sk(). Fixes: dd767856a36e ("xfrm6: Don't call icmpv6_send on local error") Cc: stable@vger.kernel.org Reported-by: Vega Signed-off-by: Zhiling Zou Signed-off-by: Steffen Klassert Signed-off-by: Greg Kroah-Hartman --- net/ipv6/xfrm6_output.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/net/ipv6/xfrm6_output.c +++ b/net/ipv6/xfrm6_output.c @@ -19,7 +19,10 @@ void xfrm6_local_rxpmtu(struct sk_buff *skb, u32 mtu) { struct flowi6 fl6; - struct sock *sk = skb->sk; + struct sock *sk = skb_to_full_sk(skb); + + if (!sk) + return; fl6.flowi6_oif = sk->sk_bound_dev_if; fl6.daddr = ipv6_hdr(skb)->daddr; @@ -31,7 +34,10 @@ void xfrm6_local_error(struct sk_buff *s { struct flowi6 fl6; const struct ipv6hdr *hdr; - struct sock *sk = skb->sk; + struct sock *sk = skb_to_full_sk(skb); + + if (!sk) + return; hdr = skb->encapsulation ? inner_ipv6_hdr(skb) : ipv6_hdr(skb); fl6.fl6_dport = inet_sk(sk)->inet_dport;