Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 0A00E3AF662; Mon, 23 Mar 2026 16:26:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774283165; cv=none; b=kS3Bz44v0+qT1TmJnBE/90wLcUMSCGEctKe55J6pEyI9f4cAzNeUmirA7fKXuDTnHT88kP+h5x/KOi1y7jFp2Pn9//0cqqt5EnLtQ0LZmyNHwGJJFQZJY+Suegrai/zMJNLuydhxfdwazzYyZSNdK82jourm6Eu87jLc3ldV2OU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774283165; c=relaxed/simple; bh=WrQG/S62rpOUTYki/AdOzPsXPNZWR3IFRtE/cR1HO2k=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=mPb/UmWFtw7TESxbLTzKi7b7NA9ZRfgwqacUdAQux2ZKh0UADkb8PNHw/EP54XnXSzjh2oJic48pK0BZLIiLoZ5vcu45XI+zQiknpf6Q/KOFIFzTeHsfUqXeWcjlB7ET8D41V5ziqLe+hp9z3bq74EVCoCbxSOKuNwDQUEXtkhE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=w6ozXgWG; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="w6ozXgWG" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9770FC4CEF7; Mon, 23 Mar 2026 16:26:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774283164; bh=WrQG/S62rpOUTYki/AdOzPsXPNZWR3IFRtE/cR1HO2k=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=w6ozXgWGF0NAWYJ4pZekMCpFSzDmNpAvsJN8po8xByiogYsDVYVHJt8ZmHEI8N3Y4 wtLduMEhyI5lzuEhdLJIlea5AffGB96MBDRntBzQvBiDX7NT3CJjM7BUgHlJamJqPB CoVlnWAw2g3QbB6/muHf68xVnZtHOOwpWsgfywzg= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Klaudia Kloc , =?UTF-8?q?Dawid=20Moczad=C5=82o?= , Jenny Guanni Qu , Florian Westphal , Sasha Levin Subject: [PATCH 6.1 419/481] netfilter: nf_conntrack_h323: check for zero length in DecodeQ931() Date: Mon, 23 Mar 2026 14:46:41 +0100 Message-ID: <20260323134535.406458432@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260323134525.256603107@linuxfoundation.org> References: <20260323134525.256603107@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jenny Guanni Qu [ Upstream commit f173d0f4c0f689173f8cdac79991043a4a89bf66 ] In DecodeQ931(), the UserUserIE code path reads a 16-bit length from the packet, then decrements it by 1 to skip the protocol discriminator byte before passing it to DecodeH323_UserInformation(). If the encoded length is 0, the decrement wraps to -1, which is then passed as a large value to the decoder, leading to an out-of-bounds read. Add a check to ensure len is positive after the decrement. Fixes: 5e35941d9901 ("[NETFILTER]: Add H.323 conntrack/NAT helper") Reported-by: Klaudia Kloc Reported-by: Dawid Moczadło Tested-by: Jenny Guanni Qu Signed-off-by: Jenny Guanni Qu Signed-off-by: Florian Westphal Signed-off-by: Sasha Levin --- net/netfilter/nf_conntrack_h323_asn1.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c index c972e9488e16f..7b1497ed97d26 100644 --- a/net/netfilter/nf_conntrack_h323_asn1.c +++ b/net/netfilter/nf_conntrack_h323_asn1.c @@ -924,6 +924,8 @@ int DecodeQ931(unsigned char *buf, size_t sz, Q931 *q931) break; p++; len--; + if (len <= 0) + break; return DecodeH323_UserInformation(buf, p, len, &q931->UUIE); } -- 2.51.0