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 7C72B3AFCE3; Sat, 30 May 2026 18:08:23 +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=1780164504; cv=none; b=VhrzoRwNC5FuUgEIHRtRW8h+sC3xYqRapz4RLvnxCa54GQv6hJz8Jn8PV+ZKNjIdhdFwIi8/ZYo1SECeIIlM4v/Nk2kqiiK1XA2mP9xMAJeGg0hF/r53jWY23iblkpYSmKnqEomnNbdHRFdalycvQiKvxlfR6SnG1TxeiPoNTZc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780164504; c=relaxed/simple; bh=4G8DotZc/2o5P4ght2k8qEIIwtirmwJhTMyQyUC74os=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oTBQJRSHENsXMHrp4pJD22X5dmSSOHBP89TDKTWo4Aq7avA4hqnh2k+I3Ei76JfGEGNAufqP04N35acYRe6Ye13//tU6mLSmlBRzDS7LtZXUKLhf72NbznOkzUfbyQ6Ulbmk4dLT72t5U1InRmzBFp3vbIZVBGB5aHv3Y15LDdw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2KPTBH1m; 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="2KPTBH1m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C1B5B1F00893; Sat, 30 May 2026 18:08:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780164503; bh=I7Rww/iRmHBPFGpwN5K8zCYGgqrABttLbgHq7sukAwY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=2KPTBH1mvLHKOekuB70RHXYjmzvLstOsWNKpepv96qFTzsUYEIvNSOvmR7EcWMGzg GiyRno8pIspkw7LyuMlsnCWfQPP0jFbYIuSCjwZvCbuLmP4X8DtCEOTdPjkeuE676Y joTj4brMpfWxF/yQRF9e1LohgcPR7rtFuv674AW4= 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 5.15 574/776] netfilter: conntrack: remove sprintf usage Date: Sat, 30 May 2026 18:04:48 +0200 Message-ID: <20260530160254.936011395@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160240.228940103@linuxfoundation.org> References: <20260530160240.228940103@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 5.15-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 3bc7e0854efe4..41c30065dae12 100644 --- a/net/netfilter/nf_nat_amanda.c +++ b/net/netfilter/nf_nat_amanda.c @@ -62,7 +62,7 @@ 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 f0a735e868518..15d4267cf49ff 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"); @@ -430,7 +432,8 @@ 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"); @@ -450,8 +453,8 @@ 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 */ @@ -466,7 +469,7 @@ 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); } @@ -503,7 +506,7 @@ 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; @@ -521,7 +524,7 @@ 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; @@ -541,7 +544,7 @@ 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