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 30B873446C9 for ; Thu, 23 Jul 2026 14:53:30 +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=1784818414; cv=none; b=j834wCUKTpz8Bo/gnrV0CQrXtWZX958RNuko+Z3R/2aF8CR7MC3y5uxxffFaaeCHV3nui+ov4AFFGZtNbLEjFYBnO+oAg9diJHmAGk986bhUKfhiFjFEtaYPtMxTELDqeWhlw1xt0Vo7uZuW6Y2WS+dAfQzDOKpnVA5Sie/VQs4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784818414; c=relaxed/simple; bh=ah02gPMpj+EIZYGfxgjH0v/2l8YJEnbFSEjLmAUYWZ0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sBF7dTiPiEz1y9M/bjkJ2Oz0nIFhnWk+0HI48gKiziCw/4s2peVEkQFrL6QiI3jnKelTY/qdjEBso+pmt50yweQzIhhqV/bozeKces5+IxuhmibERtg4lNymCt6A2KJWy1IgwRZfCsIAvDf2a4u1XNJkR435UVoDtkWh1+ielCY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2C26C1F00A3D; Thu, 23 Jul 2026 14:53:30 +0000 (UTC) From: Sasha Levin To: stable@vger.kernel.org Cc: Pablo Neira Ayuso , Ren Wei , Florian Westphal , Sasha Levin Subject: [PATCH 6.6.y 2/2] netfilter: nf_conntrack_sip: validate skb_dst() before accessing it Date: Thu, 23 Jul 2026 10:53:19 -0400 Message-ID: <20260723145319.3272168-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260723145319.3272168-1-sashal@kernel.org> References: <2026072003-scorch-encourage-ddad@gregkh> <20260723145319.3272168-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Pablo Neira Ayuso [ Upstream commit e5e24a365a5e024efef63cc49abb345fbd4852c5 ] tc ingress and openvswitch do not guarantee routing information to be available. These subsystems use the conntrack helper infrastructure, and the SIP helper relies on the skb_dst() to be present if sip_external_media is set to 1 (which is disabled by default as a module parameter). This effectively disables the sip_external_media toggle for these subsystems without resulting in a crash. Fixes: cae3a2627520 ("openvswitch: Allow attaching helpers to ct action") Fixes: b57dc7c13ea9 ("net/sched: Introduce action ct") Cc: stable@vger.kernel.org Reported-by: Ren Wei Signed-off-by: Pablo Neira Ayuso Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nf_conntrack_sip.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 911e35e3b71be0..bd91b8b47f4b75 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -947,7 +947,6 @@ static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff, return NF_ACCEPT; saddr = &ct->tuplehash[!dir].tuple.src.u3; } else if (sip_external_media) { - struct net_device *dev = skb_dst(skb)->dev; struct dst_entry *dst = NULL; struct flowi fl; @@ -969,7 +968,11 @@ static int set_expected_rtp_rtcp(struct sk_buff *skb, unsigned int protoff, * through the same interface as the signalling peer. */ if (dst) { - bool external_media = (dst->dev == dev); + const struct dst_entry *this_dst = skb_dst(skb); + bool external_media = false; + + if (this_dst && dst->dev == this_dst->dev) + external_media = true; dst_release(dst); if (external_media) -- 2.53.0