From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pj2-f12.google.com (mail-pj2-f12.google.com [74.125.227.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C33442DB785 for ; Sat, 19 Sep 2026 21:52:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.227.140 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789854772; cv=none; b=GMLjyBuQMC8e+RMeyTxLFt9OkwtnikPnlXzHOo7/n1h/i9TdHzM2FI21iWdeqYSlC8gqWtf3deb3DM/SzTq1M2Gd/XDdy54TI1tnT/DZ6m8nGq4b7eiI+AXY9/pmQtP8rRolEX8QWfbIJs+aAn9rLxaptF68CSo/Cu42oCwreLg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789854772; c=relaxed/simple; bh=ok7q8RjuE02Bww+2QvSjqNtvkMyCStknUKyLWbBaTyI=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=BZXqqJdIeQFKmmpqQTpif4Q6zGlyZY+WfTFxiCCQfSHRFiFi+2/0XXHNFAFAMJsId3Z4TLxDtoTpRJ/07oH/53srJU54+202+GcWKcX99FVXEXjeSjO3s21rSfsyBMjv52ZCpcjEl3IccQvWqcj27M3+8B1mywbVxJOnu9EQOXI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=PwXrRn6c; arc=none smtp.client-ip=74.125.227.140 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="PwXrRn6c" Received: by mail-pj2-f12.google.com with SMTP id d9443c01a7336-2d747ed6d6eso18528765ad.2 for ; Sat, 19 Sep 2026 14:52:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1789854763; x=1790459563; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=Cp35LkaPgGuGmcugrLJDe3EFri8Cdl2WjJc6hIpiryg=; b=PwXrRn6cQlBooUIymKChwIp4+XG5Gw6XmGayioQv/YymQnxBptgc9e77iOSJ2PipL5 dqJgc6xz6QTUkcGOPunig3s+D/W+89ajnwtsg8ntizY1qBDVP1styBx+4gBF+D2Y3pPj W7yibt025sqDOPNQz19Ac4tZ/zKEwFxUQfQ708Il9Tq/CZ/+jtcNEQPZu6dff32mTzQC WgAK9H234C4VnQtFC4nlAQyxa3gjQVIxXFDzo60w3TiIVz9ivVYxh+/aSX6Qq4lEnPOA l7EJf2pGe2gZCCRkWJbllFvlHXOjv7huQj4GbIoOvGb7WhOr5foSFIE4P5NqG1JcL2Gs zmog== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1789854763; x=1790459563; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=Cp35LkaPgGuGmcugrLJDe3EFri8Cdl2WjJc6hIpiryg=; b=wH8VnavXCIb+pGwx9WDQepDMhhV1auYsOckq6pH+cpkJozGJ/57cyhXkj9PWbAqkUd 88ZwlqNn6xBt0BKIVBH+ZySQI3uaXrzptbtyJSScj7GydTSyEI+VZDByIFPXMenIuLHc lrFyVE19YzKHGXUQg5pNFyXc/c8dGFcyUAgSsgvwLSEBm0VM6igdo0rdpRKRTEkhbqiJ cAGWLesf54iv7Fj7TzN2IecAni2K6j7Ki94MrrOJ+vW/Pno800drhdBzHlLv+sp1JMgk T9wjWMACRbZL8EWCyv+aXHSdvb5LCgOcTSxgbKhMMjvtpTq1Q9KYQWA+vlPt3VZI5pRT Fu9A== X-Forwarded-Encrypted: i=1; AKwUvBymcVPEiG4zciawDTntXEANdEHI3NwNy32z6q/qcywoswCNceoW4EJYQ4ZnshafkJXRgv8QZVvFUC1u3OM=@vger.kernel.org X-Gm-Message-State: AFuF++lmILcWyT9LX3EpA1tXjVJm6e9+SMunXwv4uyoGHxpSChHSBUk5 aQLtuBjya59miW6HepVTYnstjANsiYyOKyZpQcPl7+q1B2uxsYP8EOmk X-Gm-Gg: AYBFou2z8bUbzBIKh3F7H8pVK5TklS4dBViVTDFRrbtTiLKmdW8gEUTjnXVzfy5jfqP KJ/ZuEtH78hru4xgfgY6k1dKua8BC5HJlQstwk9SPzeXaR1rN0MN7MYNDMUyzLkBoAerbxnCUWQ RwvB2ugEvPhl3RugyiouOm8eABfu20JWlJBpdCz97Ep3GTovRuoPkAjlRQzV7DzJRVdD/4raEZ9 HNKNFMDl0LA2ovzfbIGpMNSEza1yFOE5+p96gaWGFRh92WAVNSH38RN8lgNk8Lq7Zt3ZwwUWqyM f6eEP1c+QmSLX4hRJCZxHshcYU6JQ4LPrzAxOXDa+/W9tskd561TUpurgEORVUhXhMwGVm7eABA uOblfexqUOhB8pE1jsns9/UPVMu6TpX7YSJRmdg8Nxl1w2YHSllx5p74SKPMge8pQMtPR9qg+P5 AjMJs6CwW+em32VPLJIbfpBHG3jv3mp7SfW0gcCegBuN1J2ze+LoaM2K2VX/LukOs2bQ8a2fs3p 8aFNsEnKk1bgc4gqL68mGGxuo//lZGgdeRD3U1rNHr/Do28ISbHGZ+nSNaNd40NboopAq2euQiT 8M03c5H11w== X-Received: by 2002:a17:903:2343:b0:2db:3b35:1ac6 with SMTP id d9443c01a7336-2ddb1ab24edmr114324035ad.5.1789854763351; Sat, 19 Sep 2026 14:52:43 -0700 (PDT) Received: from phui-2.c.googlers.com.com (78.123.83.34.bc.googleusercontent.com. [34.83.123.78]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2df3ae73eb9sm3264875ad.44.2026.09.19.14.52.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 19 Sep 2026 14:52:42 -0700 (PDT) From: Hui Peng To: pablo@netfilter.org, fw@strlen.de, phil@nwl.cc, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: netfilter-devel@vger.kernel.org, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] netfilter: nf_nat: fix unsigned range_size underflow for ICMP and GRE when max < min Date: Sat, 19 Sep 2026 21:52:42 +0000 Message-ID: <20260919215242.3471883-1-benquike@gmail.com> X-Mailer: git-send-email 2.55.0.1082.g2b9226bbc0-goog Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit In nf_nat_l4proto_unique_tuple(), when NF_NAT_RANGE_PROTO_SPECIFIED is set for IPPROTO_ICMP, IPPROTO_ICMPV6, or IPPROTO_GRE with max < min, computing max - min + 1 in a u16 range_size underflows (and wraps to 0 when min == max + 1, causing a divide-by-zero in % range_size for GRE). Handle max < min gracefully by swapping min and max for ICMP/ICMPv6 and clamping range_size to 1 for GRE, matching the TCP/UDP/SCTP path. Fixes: 203f2e78200c ("netfilter: nat: remove l4proto->unique_tuple") Assisted-by: LLM Signed-off-by: Hui Peng --- diff --git a/net/netfilter/nf_nat_core.c b/net/netfilter/nf_nat_core.c index a4858c2b2d65..83f4eb63a584 100644 --- a/net/netfilter/nf_nat_core.c +++ b/net/netfilter/nf_nat_core.c @@ -575,8 +575,10 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple, range_size = 65536; } else { min = ntohs(range->min_proto.icmp.id); - range_size = ntohs(range->max_proto.icmp.id) - - ntohs(range->min_proto.icmp.id) + 1; + max = ntohs(range->max_proto.icmp.id); + if (unlikely(max < min)) + swap(max, min); + range_size = max - min + 1; } goto find_free_id; #if IS_ENABLED(CONFIG_NF_CT_PROTO_GRE) @@ -596,7 +598,11 @@ static void nf_nat_l4proto_unique_tuple(struct nf_conntrack_tuple *tuple, range_size = 65535; } else { min = ntohs(range->min_proto.gre.key); - range_size = ntohs(range->max_proto.gre.key) - min + 1; + max = ntohs(range->max_proto.gre.key); + if (max < min) + range_size = 1; + else + range_size = max - min + 1; } goto find_free_id; #endif