From patchwork Sat Nov 2 20:33:10 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Yi Zou <03zouyi09.25@gmail.com> X-Patchwork-Id: 13860239 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-lf1-f41.google.com (mail-lf1-f41.google.com [209.85.167.41]) (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 662BE4EB50; Sat, 2 Nov 2024 20:33:24 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.167.41 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730579606; cv=none; b=Qj6uzV8rNC31A2ZJavMozEpLwNy0V4nBSyNgDhqiXFfgKirxGZB88zG+iA9FQ2ppCHP4QdM4OW6KNhFrw2TykH6dPHSbiPsg/BwH6BjJBN1ryoEzzwYNucKs+In2J86VMHmBLNHegMaR/EC8OeorPCqekC+ocB1zUZOwoN7pPFA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730579606; c=relaxed/simple; bh=cPnQwBZYflq7d5IMs6Ay6eoaThFmiNtPLwzwsAEt94g=; h=MIME-Version:From:Date:Message-ID:Subject:To:Cc:Content-Type; b=NCWlQxgYcxNgj6RHpi7PnCvJMRk/TqzNSvjxuUl5gcaqB9XgrnbOfyZo0NJABp5eVb3tI5ct1Cp/tA+sNL5k/nJXNi+7yXNMHo7u2o9Y8RbRR6KqSMTwyvLllsc+5ps+nG+KnuM8vBqq2uXMCCpstF1E72XrFTYYOtQN3rATYnM= 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=dNqbHqCV; arc=none smtp.client-ip=209.85.167.41 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="dNqbHqCV" Received: by mail-lf1-f41.google.com with SMTP id 2adb3069b0e04-539f72c8fc1so1356838e87.1; Sat, 02 Nov 2024 13:33:24 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1730579602; x=1731184402; darn=vger.kernel.org; h=cc:to:subject:message-id:date:from:mime-version:from:to:cc:subject :date:message-id:reply-to; bh=cPnQwBZYflq7d5IMs6Ay6eoaThFmiNtPLwzwsAEt94g=; b=dNqbHqCVTsC21VTUUnyz5vVNXYonGvh2mp4fYAR4rvtZJzhMbFE/MrtuEqLNZdxFIr gD0YZVy+JydkmS6FXHRD4/32vyPecKgLAo2r7rlX77K6fDm2QbQYyHvJrjzQyBWoT78i XY8v49MhDIDUKzYgE9oaceOidH9scAtcEGjx7Gt76QnhDxeIvSPGGkInBRIPBiPqXEDZ CwYH75kupIRH4tjQmVMN/UO2UyfYi0Ja4uAg9/Vq+0VoXl9NdLEP1sPPWSHIgFbiViZR EATm+jds+XOEfUAXkup3ZEXu0OoVeKAB2bCDuns9QnRr+sZ34VozFhUMiQsBFl/S6FLh fKew== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1730579602; x=1731184402; h=cc:to:subject:message-id:date:from:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=cPnQwBZYflq7d5IMs6Ay6eoaThFmiNtPLwzwsAEt94g=; b=osQFHX3mFkogmqqGmtLhwTPFymsA2AdQWccqWrfFL9Dg+aLsdaUT+Qb7IFrjoW0mvF bGU4vpFDFgbCW9AYBoUvqssioGDu0OzfYuHDU9HbaKhbvWUM1cML99DSfiOt7yga3taI FG02zIPgMMs/Vgi4eNi92KWIv78ps569kpb7+K91/GB+M38ZOZkd7Obm0w7Wl/GsTC// Ds2xZNLWba8Z0jOo6WIbCf7EwWk5v7tHfEGs300FoTKaFGdDJ5Ytja8Tsewkz9rp0Mph eJxL5kdRplbRwE6thkf6IK8fJ/ozha+Z53KkwhcLALDTdWaz4fmZaHwsLN+ujvLWd1RI EJrQ== X-Forwarded-Encrypted: i=1; AJvYcCVD7ZiuT9Uo0GyaDu49+0BVdFp44iwcp73xDOpJcdF4rB6f3Kz/1XfKRfa7uGPh6S07RO63EOH2FTYcAMw=@vger.kernel.org, AJvYcCWzRvMlAde+muzIqjb5O6EDxoP33WnQlviFI9i8o4N/mlEoHJSHgARh9QCjXhCXsE0qpulGlUDg@vger.kernel.org X-Gm-Message-State: AOJu0YxRBT9l64WIMwGtlDXTMRcLmX9x17p+k0NT/ElbX3GuDrkPFxoq Bua4GQoInTO0dBNZW6faKqb5CXtnQ4MwQtkoA7pcZh545C3E+/JE8vPw1RPvqmoCIWASOC/V+wL ibmy979tgtnYnsk7ugqrTX7JVUJ8= X-Google-Smtp-Source: AGHT+IGoqXppe9fIqDPc/oxsvYg0tqjNuy7LHBTRSrIgWw+QL8DbNnZF6mzI/2dKk2JIvPJ2TGP0zQ1/jEXFYu9I2XM= X-Received: by 2002:a05:6512:e9b:b0:539:fbfd:fc74 with SMTP id 2adb3069b0e04-53b7ed185a8mr8536911e87.40.1730579602168; Sat, 02 Nov 2024 13:33:22 -0700 (PDT) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Yi Zou <03zouyi09.25@gmail.com> Date: Sun, 3 Nov 2024 04:33:10 +0800 Message-ID: Subject: [PATCH] ipv6: ip6_fib: fix null-pointer dereference in ipv6_route_native_seq_show() To: Markus Elfring Cc: "David S. Miller" , 21210240012@m.fudan.edu.cn, 21302010073@m.fudan.edu.cn, David Ahern , Eric Dumazet , Jakub Kicinski , LKML , netdev@vger.kernel.org, Paolo Abeni X-Patchwork-Delegate: kuba@kernel.org Check if fib6_nh is non-NULL before accessing fib6_nh->fib_nh_gw_family in ipv6_route_native_seq_show() to prevent a null-pointer dereference. Assign dev as dev = fib6_nh ? fib6_nh->fib_nh_dev : NULL to ensure safe handling when nexthop_fib6_nh(rt->nh) returns NULL. Fixes: 0379e8e6a9ef ("ipv6: ip6_fib: avoid NPD in ipv6_route_native_seq_show()") Signed-off-by: Yi Zou <03zouyi09.25@gmail.com> --- net/ipv6/ip6_fib.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) -- 2.44.0 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_file *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 |= RTF_GATEWAY; seq_printf(seq, "%pi6", &fib6_nh->fib_nh_gw6); } else { seq_puts(seq, "00000000000000000000000000000000"); } - dev = fib6_nh->fib_nh_dev; + dev = 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 : "");