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=1793714616; b=E8G+KNlIrjQ5fDdMqa1Q87pkySEs6ggB1T9E90CEqvAqck2lIOgUK7pRuxaVUxWVadNB 8yuBnorGnEAzZU/10YJgapaZFV7qlZvvgzQbABlrhSoqK5pnah20D6i+iiTWROf19USVv DfNXSK8t2kplZBFy45lHkEdlXOsErjn9PFAHN3QXJoZgXjNMiDCs5n92SgDTiBnnWrfaz T3aAnmLPZ8ACXRky+PzTzfxHfY4UEkYemrwx5HnDaT0elqFNpwnRHS72F9GwmI5u3WolL CG5znMe5Rk0XDG1HTp+gsUZGPgLnLEuK0y1YrRxd7uuCSojfkWGQPHEEnYq2N6B7rNA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793714616; 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=FuJwpB61dP51oRlLlxUKS/oBV8WRen9wZFI8yNkRer0=; b=terIMczls87ucNRwU7p31BeZWqIqAg8w91bXcgSGkCc+bpO7A7FjpAtlu5jWuqQ9OxEt egDiFtm74acOHCBRKRfC0SDGGZXBAFRApFyc1nSYruw6a7S9eHtQXaSdHT1sj+sKgSG+f La5kgK+0KlHN0DWdIjdL2KNsb//4dw0D/jDdNnKo0VggYT24dsXF3PqtshHvbHUo8TOs8 EVD9zWJCgOmHQjcJm3MybLLZnkK+arpm+JrAmVh+lc+1w2Duw1KzgGMqdeAC8ova+siZn G/cikMa42pvCQsPf8m4lSA72yO/thKXN0jpoxk2rZqkAHH1hv5UzASW85iFaTU0i6Dg== 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=gLu+qAdQ; 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 A837C608509D; Tue, 3 Nov 2026 14:03:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org A837C608509D 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, unprotected) header.d=netfilter.org header.i=@netfilter.org header.a=rsa-sha256 header.s=2025 header.b=gLu+qAdQ DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=netfilter.org; s=2025; t=1793714613; bh=FuJwpB61dP51oRlLlxUKS/oBV8WRen9wZFI8yNkRer0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gLu+qAdQQNjfDZkyizCFLZdqAanMpoFyRJb3Zs6pCsT93YlKtRjxd1X0Jn6WcEYSH tjgNQiqdxyj/yDMApbhhLHelpX9UFPvJReRN7FxRFKWyyJlCFrWjr9hJT8YrYR+NGS Afb95jPosnj4NLlLccBMP4QQrlbMx0lmdMpQxITeC9DUTfyDH7aacETCQ3HPBTLJUw HfOZ0v3X+MjTK9MzAG3+OvG0LS+nfFsnRU9jBuqSW3EYghJxVSDFqxcJ328uzq4kxg Geq4wXSmDfUHBhmYBKQt4nhE7dZplklH/j8U6yleNEIpjZgS+g1cn9JeCN4DyhFTGn PNfLG5LjiVAYg== Received: from localhost.localdomain (mail-agni [217.70.190.124]) by mail.netfilter.org (Postfix) with ESMTPSA id 3230460090; Tue, 3 Nov 2026 15:03:33 +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 12/15] netfilter: nf_conntrack_sip: fix OOB read in ct_sip_parse_transport() Date: Tue, 3 Nov 2026 15:03:05 +0100 Message-ID: <20261103140308.591690-14-pablo@netfilter.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20261103140308.591690-1-pablo@netfilter.org> References: <20261103140308.591690-1-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: Joas Antonio dos Santos ct_sip_parse_transport() compares the value of the "transport=" header parameter against "TCP"/"UDP" with strncasecmp(..., 3), but it never checks that the parsed value is at least 3 bytes long. ct_sip_parse_param() returns matchlen = end - start, where end is the next ';' or, when there is no ';', the end of the payload buffer (limit = dptr + datalen). If the "transport=" value is only 1 or 2 bytes long and runs exactly to the end of the payload (e.g. a REGISTER request whose Contact header ends in ";transport=T" with no trailing CRLF), matchlen is less than 3 while strncasecmp() still reads up to 3 bytes, reading 1-2 bytes past the end of the linearized skb data. Add a matchlen check before the comparison, mirroring the sdp_media_type() pattern a few lines below, so short values cannot reach strncasecmp(). The bug was found by LLM-assisted manual review of the SIP helper's parsers and confirmed with a userspace ASan harness built from the verbatim parser functions, which reports a heap-buffer-overflow read of size 2 in strncasecmp() called from ct_sip_parse_transport(). Fixes: ea45f12a2766d ("[NETFILTER]: nf_conntrack_sip: parse SIP headers properly") Link: https://patch.msgid.link/20260815133104.50369-1-joasantonio108@gmail.com/ Signed-off-by: Joas Antonio dos Santos Assisted-by: Claude:claude-opus-5-5 Reviewed-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_sip.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/netfilter/nf_conntrack_sip.c b/net/netfilter/nf_conntrack_sip.c index 64bc440b1181..b05dc8858d09 100644 --- a/net/netfilter/nf_conntrack_sip.c +++ b/net/netfilter/nf_conntrack_sip.c @@ -701,9 +701,9 @@ static int ct_sip_parse_transport(struct nf_conn *ct, const char *dptr, if (ct_sip_parse_param(ct, dptr, dataoff, datalen, "transport=", &matchoff, &matchlen)) { - if (!strncasecmp(dptr + matchoff, "TCP", strlen("TCP"))) + if (matchlen >= 3 && !strncasecmp(dptr + matchoff, "TCP", 3)) *proto = IPPROTO_TCP; - else if (!strncasecmp(dptr + matchoff, "UDP", strlen("UDP"))) + else if (matchlen >= 3 && !strncasecmp(dptr + matchoff, "UDP", 3)) *proto = IPPROTO_UDP; else return 0; -- 2.47.3