From nobody Sun Nov 24 23:36:38 2024 Received: from mail-pl1-f173.google.com (mail-pl1-f173.google.com [209.85.214.173]) (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 F0067139B; Fri, 1 Nov 2024 04:48:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.173 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730436518; cv=none; b=NSV9jzE6S9qHrXLPHt4Zzxe91AgRPrqNBEKo+5eS5Z+lJAPwqOVD/w3fosQQHRb3QsNA0TqctTzmJC3yjmL0rPv7rvrF5oCPYGA4UFJh3CjLvMcW7YGiKyMNcb0TqCP9TCdkNEtaXiearPasaTKDtTDr3UXpObRANMBwN8a5Nrw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730436518; c=relaxed/simple; bh=goupBVKKF4uoCNiNKh9pKJyH7g/obcamc9uDsfjlrVw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=dTmoTmbQ+hLG401452TJu3CGakcORu6UHPP42otpAywziUsgK5VSxg4Z317it42HiZ+2V0YC52F4zTvnvH0Ska4+uOxR8OFESgP/pq74qUvPPO+DfWHCNWOtdCsmaDFuyScBjoSl87iFs5wAhyL7xt9pU3ggSCTt90nnBoqPn5E= 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=UBUfjTzH; arc=none smtp.client-ip=209.85.214.173 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="UBUfjTzH" Received: by mail-pl1-f173.google.com with SMTP id d9443c01a7336-20c714cd9c8so17475075ad.0; Thu, 31 Oct 2024 21:48:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1730436516; x=1731041316; 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; bh=Fx1RChMr66gIWYhPNL1PsqJ/YHNLAl0LYOv2JnnTM64=; b=UBUfjTzHEGH+NIJ5lsS9GaTx9UVqXt06t5gL27DlvwuUom6DX+VPkP2VszoTFDz3ho yL0glAFj5ROJ6WWkhSzAxZqDmGj00O8DTKuiKvfQzEDHFsItsr4ixaok9ajJJ6cEWJ9g tXGOZfgk2igCMfZ8wvpQAZvY8L8KRa7VrO9jKIn1ecQVHEIdesN44n3crM7+lYogPvlL MoxjkSAjZYykZGXw7Fchj/nlSzp6NKPgMqd2wE62Gf1BbVbl9NoZ93kBgxaL/7hu23vJ n2itPzwwnCBIih2vQbaChP3FwHaje87zC4CAwER14aZfXD/KY35a0rIx1SEjvLn1jjn4 D+Ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730436516; x=1731041316; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=Fx1RChMr66gIWYhPNL1PsqJ/YHNLAl0LYOv2JnnTM64=; b=pFDYRHCP13B766PBNH+9an1I+hf4FhoHWMaeR6UVuAockmmf/P1La2r9MAJYHt1tEu N4ZRjhJ4GK5TQQPFAL8+NZ+LeEYZUvz3pvfF7aydW9T4lGuN+aYDHhWMjMJmcqDjy9Uq JC2ZPMtQd4jMor1akTLh3ibnaNsSXe9yeP1bO9UN282bXmuD/wPdEhGZNGpnsdKw+3M1 kA+vVEMYsYspNgr9L8GD+LmPcXt3nXsaFNRexVIvSWUoUl7Uzu+Umq6NIE18wA5Lk5Id W0ne7XNRJIB99nM06rTN6H43+cbwi6cZfL4aWNMg4m8pZqSkkGXn3jwPoNmX5ovBGVaj tpsA== X-Forwarded-Encrypted: i=1; AJvYcCVIST3qmE7hFEtJZVQQysCF8xgVgLjLZK3juj9CaCLigQvCO9ABqAHG5FJ/o3fsMII832R6/oxt@vger.kernel.org, AJvYcCWkSmXDGx98+L8MnKqctIaSMCfqMdZHN4ylOWchPJvRla3ywIvomN0B7nx2j2TRcpjbAAJ8/S/eijnzb2g=@vger.kernel.org X-Gm-Message-State: AOJu0Yyx78hCEZcb4fcozPrKF409uYCgyK6Dh/Ip5wH5/RMJaETDdEA/ PPwDpEFfgyAg+VGJUxAAQ5zbHAS+jqjZVwkods416p4AV5CXGxDT X-Google-Smtp-Source: AGHT+IEEMIk857bmmD7AVDexG2/qdpDowNobcbSPfjOQpeynHnn2y0pAVGvCRKS+NHwwh5UODrqXQA== X-Received: by 2002:a17:902:ec81:b0:20c:fb47:5c02 with SMTP id d9443c01a7336-2111b01aff0mr23099375ad.52.1730436516122; Thu, 31 Oct 2024 21:48:36 -0700 (PDT) Received: from localhost.localdomain ([101.94.129.40]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-211057a59a8sm15890625ad.130.2024.10.31.21.48.32 (version=TLS1_3 cipher=TLS_CHACHA20_POLY1305_SHA256 bits=256/256); Thu, 31 Oct 2024 21:48:35 -0700 (PDT) From: Yi Zou <03zouyi09.25@gmail.com> To: davem@davemloft.net Cc: 21210240012@m.fudan.edu.cn, 21302010073@m.fudan.edu.cn, dsahern@kernel.org, edumazet@google.com, pabeni@redhat.com, kuba@kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Yi Zou <03zouyi09.25@gmail.com> Subject: [PATCH] ipv6: ip6_fib: fix possible null-pointer-dereference in ipv6_route_native_seq_show Date: Fri, 1 Nov 2024 12:48:28 +0800 Message-ID: <20241101044828.55960-1-03zouyi09.25@gmail.com> X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" In the ipv6_route_native_seq_show function, the fib6_nh variable is assigned the value from nexthop_fib6_nh(rt->nh), which could return NULL. This creates a risk of a null-pointer-dereference when accessing fib6_nh->fib_nh_gw_family. This can be resolved by checking if fib6_nh is non-NULL before accessing fib6_nh->fib_nh_gw_family and assign dev using dev =3D fib6_nh ? fib6_nh->fib_nh_dev : NULL; to prevent null-pointer dereference errors. Signed-off-by: Yi Zou <03zouyi09.25@gmail.com> --- net/ipv6/ip6_fib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/ipv6/ip6_fib.c b/net/ipv6/ip6_fib.c index eb111d20615c..6632ab65d206 100644 --- a/net/ipv6/ip6_fib.c +++ b/net/ipv6/ip6_fib.c @@ -2555,14 +2555,14 @@ static int ipv6_route_native_seq_show(struct seq_fi= le *seq, void *v) #else seq_puts(seq, "00000000000000000000000000000000 00 "); #endif - if (fib6_nh->fib_nh_gw_family) { + if (fib6_nh && fib6_nh->fib_nh_gw_family) { flags |=3D RTF_GATEWAY; seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6); } else { seq_puts(seq, "00000000000000000000000000000000"); } =20 - dev =3D fib6_nh->fib_nh_dev; + dev =3D fib6_nh ? fib6_nh->fib_nh_dev : NULL; seq_printf(seq, " %08x %08x %08x %08x %8s\n", rt->fib6_metric, refcount_read(&rt->fib6_ref), 0, flags, dev ? dev->name : ""); --=20 2.44.0