From nobody Sat Nov 30 12:33:49 2024 Received: from mail-oa1-f53.google.com (mail-oa1-f53.google.com [209.85.160.53]) (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 F35B017A92E; Mon, 9 Sep 2024 18:48:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.160.53 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725907717; cv=none; b=oby6xep3kb4h3AkY6TJgL3OYkfALu7o4cKCzSZwiCQvq7vqVd8jfnf+nd17geS2ZBm/zygXKumdBfCCVCcH10qXDRt2fyX0ILP6qvGQ2zDSMrn77WqKdZaEPb0UwsjmMztRZtdpaaZoW1PYa4KjDnHjBtHBwaObCBlH402ZJvVA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1725907717; c=relaxed/simple; bh=opDvcsNzBPHx59DExhq/FmozYJ3scDPTECogRp+m2KU=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=MF2ru6qXw9pwzRY+moTwcnmZ7rFBWgheInRiGG2guzsWAQkilJrNpChgzWra6InOqL4Xlj6NMZqC4psPUtkAbqid2B7TpMnpD10o4mVKpt0ZA5NVlp71QPkpZ4ybOfd7O4mv/m6c718IoHue1CnQgxB7B1nPO6sIRko/HxwvWR8= 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=NwXZX6QJ; arc=none smtp.client-ip=209.85.160.53 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="NwXZX6QJ" Received: by mail-oa1-f53.google.com with SMTP id 586e51a60fabf-27830bce86bso2623544fac.0; Mon, 09 Sep 2024 11:48:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1725907715; x=1726512515; 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=Evv02wRZtoNC+BDsMRqpz+3iRpxo+7R7AGdDISkteFg=; b=NwXZX6QJ/9he/sBrFaU6bW5tR66qdu5gBZQOkYfGypwh6ut4rB18e7Kd4xMJea1LbQ C5BrtUH50Ou6Rkzpt+qRPSMYY3rNB4GIHjoNevFt5g6c9XpuBhZihFjTE/KVO6igCl/m merQ9dI3fQ+oI/YHYUdhEL6kGj3JaLMrEGEL8XnkjABeecUnYiTcNEHrkfBel32l0hSR erZ12CPz4B1Q2I5wMD5Y/C5zwfCTXRgaEk/+9xHmovwxlpKswwCspUOhEbGJOzrVSmep oj3ppwDs9mx56Rk8q9QXKaaRjPM2wkbw4XT5ZIYzYT3FAQVOdCAv9u/+DDCt9nMNMaSV 40Ig== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1725907715; x=1726512515; 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=Evv02wRZtoNC+BDsMRqpz+3iRpxo+7R7AGdDISkteFg=; b=l64KCKnWuYHbsqFmTGbxbAoKa37IauBuaaXAMNKFJeqSLUzVkBf0Gn697E9IWxrvLG TkiLiCzu4SxRDYVFZs/CnY95R98xyuhITv9XCdA50fokBO9vrseBcgJKcycBUGSuHwVE 3ourHzcH9c4wjBDH46JsBFDyT51qZxufZsTkZdOggAulivcYujcLJI5caQiQ6k9k+iSL 0kgG21nx7v2GnvRXovFM9DqygLHjLJwaucr6eFQmUIC1pccWQeDezROaz51/Oe6BDSBj CIOsHEGsXqUqWHE6TraVzS1PzSOWlfe4w62o5iR+76Al4dlKqRrIbLbe9OzgvpwSc/16 /VuA== X-Forwarded-Encrypted: i=1; AJvYcCWOUFtD1+6PkRAqGTOBxiPmjrxVuSXyALLqQAtGwqA/f2oQAI1ck/i8doicVHh1RXWrQ1HVvvGc@vger.kernel.org, AJvYcCXetRJcQkVLLhtBI2oiMFimsNHR5zkHx7+/Aq5qodAHhbXf28jJCy4ZswQodpOmdCM8456FNqYnc6LMf2M=@vger.kernel.org X-Gm-Message-State: AOJu0YxmCfprqcpmBHgvoUqU72dWS/Uz0sDj+kyCMkIVw9wth8ih8ofD 431hlBeSgSXyysJoItsrACH5A6r9PjInyZ3XwWEkT9ZlKoWMvf7w X-Google-Smtp-Source: AGHT+IEbSXmGXqSJ/Yl/Tle8iq8bB++evpdiqf0ZOMgr6sl80+BemZ0IXyPtw9UcrwpnoC7xl++uJg== X-Received: by 2002:a05:6871:3a24:b0:277:f826:edcc with SMTP id 586e51a60fabf-27b9d7c0c39mr10652504fac.5.1725907714881; Mon, 09 Sep 2024 11:48:34 -0700 (PDT) Received: from kernelexploit-virtual-machine.localdomain ([121.185.186.233]) by smtp.gmail.com with ESMTPSA id 41be03b00d2f7-7d8255dc17esm3645998a12.62.2024.09.09.11.48.32 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 09 Sep 2024 11:48:34 -0700 (PDT) From: Jeongjun Park To: davem@davemloft.net, dsahern@kernel.org Cc: edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, kafai@fb.com, weiwan@google.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Jeongjun Park Subject: [PATCH net] net: prevent NULL pointer dereference in rt_fibinfo_free() and rt_fibinfo_free_cpus() Date: Tue, 10 Sep 2024 03:48:27 +0900 Message-Id: <20240909184827.123071-1-aha310510@gmail.com> X-Mailer: git-send-email 2.34.1 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" rt_fibinfo_free() and rt_fibinfo_free_cpus() only check for rt and do not verify rt->dst and use it, which will result in NULL pointer dereference. Therefore, to prevent this, we need to add a check for rt->dst. Fixes: 0830106c5390 ("ipv4: take dst->__refcnt when caching dst in fib") Fixes: c5038a8327b9 ("ipv4: Cache routes in nexthop exception entries.") Signed-off-by: Jeongjun Park --- net/ipv4/fib_semantics.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index 2b57cd2b96e2..3a2a92599366 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -153,6 +153,8 @@ static void rt_fibinfo_free(struct rtable __rcu **rtp) =20 if (!rt) return; + if (!&rt->dst) + return; =20 /* Not even needed : RCU_INIT_POINTER(*rtp, NULL); * because we waited an RCU grace period before calling @@ -202,10 +204,13 @@ static void rt_fibinfo_free_cpus(struct rtable __rcu = * __percpu *rtp) struct rtable *rt; =20 rt =3D rcu_dereference_protected(*per_cpu_ptr(rtp, cpu), 1); - if (rt) { - dst_dev_put(&rt->dst); - dst_release_immediate(&rt->dst); - } + if (!rt) + continue; + if (!&rt->dst) + continue; + + dst_dev_put(&rt->dst); + dst_release_immediate(&rt->dst); } free_percpu(rtp); } --