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 1C6403546C8; Wed, 20 May 2026 17:45:17 +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=1779299118; cv=none; b=ANFJUdn1wjfAEXnrseBo4oVn0GEmMnsHXORz09Ahey2uZLy7/IZunKrOp6hSVBT5elRcORbPlShLeFXAUnkCvI/xjSwwTANlfO9tyvqClUBEOZ65F0qVmE/bOaPwFDyzO/B8ExnujrR0FV6kFhdqezQvkF8lIrNYmxlnqaOtgIg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779299118; c=relaxed/simple; bh=2FnBSiLTAHV+x5z6M70shJCF3P44MR4e5Eql7pS7VN8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=LnkG30GTiTJKgUydvIVnWSn/TUR6Jyzlbe+foVETEb87ggBZDwEWanN+mulTrmEvTkV2lVr0qBQy5TUnuD9wK9zi5neyhpX3s64awWdosd3Wzx3oP/2R/4nedfZMpxoBqHI4P2o4wuQBXfS7o0met2ckmy+qKyBVTpPR06fOxZg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BZsyBIVk; 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="BZsyBIVk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 819E01F000E9; Wed, 20 May 2026 17:45:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779299117; bh=2I7vgzVkdVr1oKsTX32Wx2B4PhQnjApSQd/x6HxXvCg=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BZsyBIVkgE/ilwLbfS7viZ8j/ZlZF3tXbdmNdG+Wklv6lPjRTyVRQPur4XxjSNj0h i0tb0KLTzI90b7DjN1Nr5eBYUSuZauWYpF2mjh5pXoWqgY8bh1NWeMfAZmc8N2TboJ zw4YogUHKgfSqTzSyqAGDNXQDy1iObTq8x5K+QIw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Yiming Qian , Florian Westphal , Pablo Neira Ayuso , Sasha Levin Subject: [PATCH 6.18 662/957] netfilter: conntrack: remove sprintf usage Date: Wed, 20 May 2026 18:19:05 +0200 Message-ID: <20260520162148.887913526@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162134.554764788@linuxfoundation.org> References: <20260520162134.554764788@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: Florian Westphal [ Upstream commit 6e7066bdb481a87fe88c4fa563e348c03b2d373d ] Replace it with scnprintf, the buffer sizes are expected to be large enough to hold the result, no need for snprintf+overflow check. Increase buffer size in mangle_content_len() while at it. BUG: KASAN: stack-out-of-bounds in vsnprintf+0xea5/0x1270 Write of size 1 at addr [..] vsnprintf+0xea5/0x1270 sprintf+0xb1/0xe0 mangle_content_len+0x1ac/0x280 nf_nat_sdp_session+0x1cc/0x240 process_sdp+0x8f8/0xb80 process_invite_request+0x108/0x2b0 process_sip_msg+0x5da/0xf50 sip_help_tcp+0x45e/0x780 nf_confirm+0x34d/0x990 [..] Fixes: 9fafcd7b2032 ("[NETFILTER]: nf_conntrack/nf_nat: add SIP helper port") Reported-by: Yiming Qian Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/nf_nat_amanda.c | 2 +- net/netfilter/nf_nat_sip.c | 33 ++++++++++++++++++--------------- 2 files changed, 19 insertions(+), 16 deletions(-) diff --git a/net/netfilter/nf_nat_amanda.c b/net/netfilter/nf_nat_amanda.c index 98deef6cde694..8f1054920a857 100644 --- a/net/netfilter/nf_nat_amanda.c +++ b/net/netfilter/nf_nat_amanda.c @@ -50,7 +50,7 @@ static unsigned int help(struct sk_buff *skb, return NF_DROP; } - sprintf(buffer, "%u", port); + snprintf(buffer, sizeof(buffer), "%u", port); if (!nf_nat_mangle_udp_packet(skb, exp->master, ctinfo, protoff, matchoff, matchlen, buffer, strlen(buffer))) { diff --git a/net/netfilter/nf_nat_sip.c b/net/netfilter/nf_nat_sip.c index cf4aeb299bdef..c845b6d1a2bdf 100644 --- a/net/netfilter/nf_nat_sip.c +++ b/net/netfilter/nf_nat_sip.c @@ -68,25 +68,27 @@ static unsigned int mangle_packet(struct sk_buff *skb, unsigned int protoff, } static int sip_sprintf_addr(const struct nf_conn *ct, char *buffer, + size_t size, const union nf_inet_addr *addr, bool delim) { if (nf_ct_l3num(ct) == NFPROTO_IPV4) - return sprintf(buffer, "%pI4", &addr->ip); + return scnprintf(buffer, size, "%pI4", &addr->ip); else { if (delim) - return sprintf(buffer, "[%pI6c]", &addr->ip6); + return scnprintf(buffer, size, "[%pI6c]", &addr->ip6); else - return sprintf(buffer, "%pI6c", &addr->ip6); + return scnprintf(buffer, size, "%pI6c", &addr->ip6); } } static int sip_sprintf_addr_port(const struct nf_conn *ct, char *buffer, + size_t size, const union nf_inet_addr *addr, u16 port) { if (nf_ct_l3num(ct) == NFPROTO_IPV4) - return sprintf(buffer, "%pI4:%u", &addr->ip, port); + return scnprintf(buffer, size, "%pI4:%u", &addr->ip, port); else - return sprintf(buffer, "[%pI6c]:%u", &addr->ip6, port); + return scnprintf(buffer, size, "[%pI6c]:%u", &addr->ip6, port); } static int map_addr(struct sk_buff *skb, unsigned int protoff, @@ -119,7 +121,7 @@ static int map_addr(struct sk_buff *skb, unsigned int protoff, if (nf_inet_addr_cmp(&newaddr, addr) && newport == port) return 1; - buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, ntohs(newport)); + buflen = sip_sprintf_addr_port(ct, buffer, sizeof(buffer), &newaddr, ntohs(newport)); return mangle_packet(skb, protoff, dataoff, dptr, datalen, matchoff, matchlen, buffer, buflen); } @@ -212,7 +214,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff, &addr, true) > 0 && nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.src.u3) && !nf_inet_addr_cmp(&addr, &ct->tuplehash[!dir].tuple.dst.u3)) { - buflen = sip_sprintf_addr(ct, buffer, + buflen = sip_sprintf_addr(ct, buffer, sizeof(buffer), &ct->tuplehash[!dir].tuple.dst.u3, true); if (!mangle_packet(skb, protoff, dataoff, dptr, datalen, @@ -229,7 +231,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff, &addr, false) > 0 && nf_inet_addr_cmp(&addr, &ct->tuplehash[dir].tuple.dst.u3) && !nf_inet_addr_cmp(&addr, &ct->tuplehash[!dir].tuple.src.u3)) { - buflen = sip_sprintf_addr(ct, buffer, + buflen = sip_sprintf_addr(ct, buffer, sizeof(buffer), &ct->tuplehash[!dir].tuple.src.u3, false); if (!mangle_packet(skb, protoff, dataoff, dptr, datalen, @@ -247,7 +249,7 @@ static unsigned int nf_nat_sip(struct sk_buff *skb, unsigned int protoff, htons(n) == ct->tuplehash[dir].tuple.dst.u.udp.port && htons(n) != ct->tuplehash[!dir].tuple.src.u.udp.port) { __be16 p = ct->tuplehash[!dir].tuple.src.u.udp.port; - buflen = sprintf(buffer, "%u", ntohs(p)); + buflen = scnprintf(buffer, sizeof(buffer), "%u", ntohs(p)); if (!mangle_packet(skb, protoff, dataoff, dptr, datalen, poff, plen, buffer, buflen)) { nf_ct_helper_log(skb, ct, "cannot mangle rport"); @@ -418,7 +420,8 @@ static unsigned int nf_nat_sip_expect(struct sk_buff *skb, unsigned int protoff, if (!nf_inet_addr_cmp(&exp->tuple.dst.u3, &exp->saved_addr) || exp->tuple.dst.u.udp.port != exp->saved_proto.udp.port) { - buflen = sip_sprintf_addr_port(ct, buffer, &newaddr, port); + buflen = sip_sprintf_addr_port(ct, buffer, sizeof(buffer), + &newaddr, port); if (!mangle_packet(skb, protoff, dataoff, dptr, datalen, matchoff, matchlen, buffer, buflen)) { nf_ct_helper_log(skb, ct, "cannot mangle packet"); @@ -438,8 +441,8 @@ static int mangle_content_len(struct sk_buff *skb, unsigned int protoff, { enum ip_conntrack_info ctinfo; struct nf_conn *ct = nf_ct_get(skb, &ctinfo); + char buffer[sizeof("4294967295")]; unsigned int matchoff, matchlen; - char buffer[sizeof("65536")]; int buflen, c_len; /* Get actual SDP length */ @@ -454,7 +457,7 @@ static int mangle_content_len(struct sk_buff *skb, unsigned int protoff, &matchoff, &matchlen) <= 0) return 0; - buflen = sprintf(buffer, "%u", c_len); + buflen = scnprintf(buffer, sizeof(buffer), "%u", c_len); return mangle_packet(skb, protoff, dataoff, dptr, datalen, matchoff, matchlen, buffer, buflen); } @@ -491,7 +494,7 @@ static unsigned int nf_nat_sdp_addr(struct sk_buff *skb, unsigned int protoff, char buffer[INET6_ADDRSTRLEN]; unsigned int buflen; - buflen = sip_sprintf_addr(ct, buffer, addr, false); + buflen = sip_sprintf_addr(ct, buffer, sizeof(buffer), addr, false); if (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen, sdpoff, type, term, buffer, buflen)) return 0; @@ -509,7 +512,7 @@ static unsigned int nf_nat_sdp_port(struct sk_buff *skb, unsigned int protoff, char buffer[sizeof("nnnnn")]; unsigned int buflen; - buflen = sprintf(buffer, "%u", port); + buflen = scnprintf(buffer, sizeof(buffer), "%u", port); if (!mangle_packet(skb, protoff, dataoff, dptr, datalen, matchoff, matchlen, buffer, buflen)) return 0; @@ -529,7 +532,7 @@ static unsigned int nf_nat_sdp_session(struct sk_buff *skb, unsigned int protoff unsigned int buflen; /* Mangle session description owner and contact addresses */ - buflen = sip_sprintf_addr(ct, buffer, addr, false); + buflen = sip_sprintf_addr(ct, buffer, sizeof(buffer), addr, false); if (mangle_sdp_packet(skb, protoff, dataoff, dptr, datalen, sdpoff, SDP_HDR_OWNER, SDP_HDR_MEDIA, buffer, buflen)) return 0; -- 2.53.0