From nobody Sat Feb 7 23:23:20 2026 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 071E7EB64D9 for ; Thu, 6 Jul 2023 13:08:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232277AbjGFNIY (ORCPT ); Thu, 6 Jul 2023 09:08:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34218 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232135AbjGFNIW (ORCPT ); Thu, 6 Jul 2023 09:08:22 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A0D6510F5; Thu, 6 Jul 2023 06:08:21 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id d9443c01a7336-1b890e2b9b7so2908975ad.3; Thu, 06 Jul 2023 06:08:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1688648901; x=1691240901; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=513dHm8kTOIuqgQPIHpSSVm+ip4pXPZmBl8EhEBgnNM=; b=lVRUYcxp1q1CO3zXBljcWb5fZEQtOxBlDoQZQPAvV2+QnQHO72aiByKy7Nc9AoYESa 1m9SkuYqdVzU534GPBL3reNPowlidbTDZieEGjcsc63ogpK/JXjZQX3EVvwI6wB4+d1H U53DCTuJWAoyMqDzJUWIwiTFLo38iSRFHf7hhgyD+C7098/BtkxzFxAmF6F6e7gXyNOQ yaius+c6dnFKdXpxktGWdeiYByq/7Ig4WvtP7Ip1C1Hg8f8LMeLn/Z/LWNRc4PFdF9y+ K6R53gDehU/RCUZs3f3yHbevtwtuy53PLEOvaK62qkrCCxOMHnid8+/PXKOqvzN1oH0t Rd6Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688648901; x=1691240901; 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=513dHm8kTOIuqgQPIHpSSVm+ip4pXPZmBl8EhEBgnNM=; b=fzAQF+6bIXTYxRa2a3DIflktH67frm7E+JnN7HguybXToOkb8PyoBTxSKJ2p7u+FtN PYN52NOGnvpCV9DC4z+0JIGpXdY+mFz3su1xlXPw2R43PKyHXQX+3U+EyEVgUXer1E9e kvvQesatS4UN1fhHpbiFixUAWW55aB4RPAzaifnh7WBQgeD0QdPmHxklffMJnIU0WI6p 0VYvqFokAKFlh0UoA1bFCkMhdNqrEDV6sSA6u0VUw4jM0HUeIHXw5iWOR6jBKCFrEc9f oY+X3GtuURoUxyCxZaC2tokSSRL+nfbs6K+7NZRdQK1W5FLM6UYwa5/nIcG7jielG18w nWUQ== X-Gm-Message-State: ABy/qLbQeqgl6NEqFPhVHFjl7NrPie2LwG1vWAp8JFsT4o557X1ychen 2b5LoMmHq1/XHy2uDTLlNw== X-Google-Smtp-Source: APBJJlH6eTLecuVTEfGC9Yd2AFb4gtrnG8N3bmkxwsVVUI+5rjy8IFcLzpTEOkfEXuZyffFdw249og== X-Received: by 2002:a17:902:aa89:b0:1b8:7d0d:5ac5 with SMTP id d9-20020a170902aa8900b001b87d0d5ac5mr1040500plr.50.1688648900925; Thu, 06 Jul 2023 06:08:20 -0700 (PDT) Received: from linux.. ([164.92.112.87]) by smtp.gmail.com with ESMTPSA id jg3-20020a17090326c300b001a2104d706fsm1391063plb.225.2023.07.06.06.08.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 06 Jul 2023 06:08:20 -0700 (PDT) From: Kaiyu Zhang To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Kaiyu Zhang Subject: [PATCH] gro: check returned skb of napi_frags_skb() against NULL Date: Thu, 6 Jul 2023 13:08:00 +0000 Message-Id: <20230706130800.85963-1-squirrel.prog@gmail.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Some rogue network adapter and their driver pass bad skbs to GRO. napi_frags_skb() detects this, drops these bad skbs, and return NULL to napi_gro_frags(), which does not check returned skb against NULL and access it. This results in a kernel crash. A better approach to address these bad skbs would be to issue some warnings and drop them, which napi_frags_skb() already does, and move on without crashing the kernel. Signed-off-by: Kaiyu Zhang --- net/core/gro.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/core/gro.c b/net/core/gro.c index 0759277dc..18d92016b 100644 --- a/net/core/gro.c +++ b/net/core/gro.c @@ -731,6 +731,9 @@ gro_result_t napi_gro_frags(struct napi_struct *napi) gro_result_t ret; struct sk_buff *skb =3D napi_frags_skb(napi); =20 + if (unlikely(!skb)) + return GRO_CONSUMED; + trace_napi_gro_frags_entry(skb); =20 ret =3D napi_frags_finish(napi, skb, dev_gro_receive(napi, skb)); --=20 2.34.1