From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-fw-80006.amazon.com (smtp-fw-80006.amazon.com [99.78.197.217]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 057D54E1DD; Fri, 7 Jun 2024 21:32:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=99.78.197.217 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717795969; cv=none; b=UtPqq33jKtFaGFMQhK7z+v+oP8SEMxIxXN8JtTMYAhUlMZUT5KJwcaf0m7DBuCbRvKCaYVb70nvnQD2p0i+nSs83lrlO4LRJkoB/YMbZfHsjxn/8aNqkygbgD2PHjR6SXvdZrQ7c2yXhbhrsdImmojZdqgU1fxsYiKjgusMn4P8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1717795969; c=relaxed/simple; bh=DtFPPuJl5jobRcYlhii4Hbqy6pyJVCflNa8vQeo+ODw=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=REWtmCwLqKjXxkGDK6zLfR79PaqKLnbepVuvHjDmflh+lbYnrx/MWoxOWiqDmoSfiv5SK5Vwf1xSNHMD4J0AGU6pP8hEem5Zj6/w8XwVHzb9GI2AkP6eBqOl+59u5TvQPvsQDJmZ4x73/s145ogX3s348crBbWMkGbFytou1r0A= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com; spf=pass smtp.mailfrom=amazon.co.jp; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b=r6KBGmCS; arc=none smtp.client-ip=99.78.197.217 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=amazon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=amazon.co.jp Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=amazon.com header.i=@amazon.com header.b="r6KBGmCS" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=amazon.com; i=@amazon.com; q=dns/txt; s=amazon201209; t=1717795968; x=1749331968; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=tDYZoP3d8/zCpLPWQHHudMPrUF8rr9i3P8lcsIGhdv0=; b=r6KBGmCSQitmi8h64oCnP1Smkrw5IoZtbkJVFNBeyam5Wb9QendXpen8 8Mi0coQOdZPAqTZDnSttgYaQ56lnuXrjqFyTlNywqDuzevv5x8A5TaBzN +4lf/8/17vkxTd0VHdrdJGnf2XTSpxWg/hLHTvjdu7IVeC+0qMv35j01+ E=; X-IronPort-AV: E=Sophos;i="6.08,221,1712620800"; d="scan'208";a="300765059" Received: from pdx4-co-svc-p1-lb2-vlan3.amazon.com (HELO smtpout.prod.us-west-2.prod.farcaster.email.amazon.dev) ([10.25.36.214]) by smtp-border-fw-80006.pdx80.corp.amazon.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 07 Jun 2024 21:32:45 +0000 Received: from EX19MTAUWB002.ant.amazon.com [10.0.7.35:15518] by smtpin.naws.us-west-2.prod.farcaster.email.amazon.dev [10.0.42.213:2525] with esmtp (Farcaster) id cb789800-7be3-4309-aa6b-c7438c91f728; Fri, 7 Jun 2024 21:32:45 +0000 (UTC) X-Farcaster-Flow-ID: cb789800-7be3-4309-aa6b-c7438c91f728 Received: from EX19D004ANA001.ant.amazon.com (10.37.240.138) by EX19MTAUWB002.ant.amazon.com (10.250.64.231) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Fri, 7 Jun 2024 21:32:41 +0000 Received: from 88665a182662.ant.amazon.com (10.106.101.48) by EX19D004ANA001.ant.amazon.com (10.37.240.138) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.34; Fri, 7 Jun 2024 21:32:38 +0000 From: Kuniyuki Iwashima To: CC: , , , , , Subject: Re: [Patch net] net: remove the bogus overflow debug check in pskb_may_pull() Date: Fri, 7 Jun 2024 14:32:29 -0700 Message-ID: <20240607213229.97602-1-kuniyu@amazon.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: References: Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: EX19D043UWC004.ant.amazon.com (10.13.139.206) To EX19D004ANA001.ant.amazon.com (10.37.240.138) From: Cong Wang Date: Fri, 7 Jun 2024 09:14:04 -0700 > On Fri, Jun 07, 2024 at 01:27:47AM +0200, Florian Westphal wrote: > > Cong Wang wrote: > > > From: Cong Wang > > > > > > Commit 219eee9c0d16 ("net: skbuff: add overflow debug check to pull/push > > > helpers") introduced an overflow debug check for pull/push helpers. > > > For __skb_pull() this makes sense because its callers rarely check its > > > return value. But for pskb_may_pull() it does not make sense, since its > > > return value is properly taken care of. Remove the one in > > > pskb_may_pull(), we can continue rely on its return value. > > > > See 025f8ad20f2e3264d11683aa9cbbf0083eefbdcd which would not exist > > without this check, I would not give up yet. > > What's the point of that commit? 4b911a9690d7 would be better example. The warning actually found a bug in NSH GSO. Here's splats triggered by syzkaller using NSH over various tunnels. https://lore.kernel.org/netdev/20240415222041.18537-2-kuniyu@amazon.com/