Received: by 2002:a05:6a10:9848:0:0:0:0 with SMTP id x8csp1601445pxf; Fri, 9 Apr 2021 12:31:53 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzW4gvEzpZ/G67gyTY3MiVRE2X3b6UNGW7TcTPuyAEqRaowHxeGnVmEwKgs8iJSA/2U8JKK X-Received: by 2002:a17:906:d554:: with SMTP id cr20mr16396764ejc.219.1617996713388; Fri, 09 Apr 2021 12:31:53 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1617996713; cv=none; d=google.com; s=arc-20160816; b=LiY2FkanVlYDhnry0ZJ4WcM4wWf7RLEWqHnKnNFt0QiQJQ0lENdQ+MBj3A/aWi65Pb L1mJra+MYw/YesDiRuvSKGOv0Uets5ZR/hXo+1GcoE4d//+Fus5G1tF8gl9G5Oayv4Je YLvQDCssbMvau7PEb3tYJDmQTW92TaPGe8JHmjMuUbfLI3pjLRuYyKSOQvqbJrm4ra00 /DIWPR4uaKw5eA6cuFMnXJ0gGQbUHNNsfkXH2Xl4Lg2PJ38AifeilwV3ZB4FckENrQXz 2D1anPXCvK8Mh12c0JfDJVEsrf/YHbhQzamQKSl3wSaoOQ4Hk/SBDFU41k+6vVJh0Tgt qXAQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:content-transfer-encoding:mime-version :user-agent:references:in-reply-to:date:cc:to:from:subject :message-id; bh=hqq5nnPgv712hJ+RfflQ/TKDdZkuhKP/E7wOR4QUgRY=; b=kj7XVqv1UbD7dBn13trK4N5EUO3DjXZCPDy4BCkUvasn7X3ozQO+0+cW07tjnKuYcb tuTg4b5ggWyoi6iEQVFoE0yKuO9PiN4ViTD8p7N90bZk2+zMStoc41+szVeanIjmQ3lO 5kTLxoHQzDcVMrQx7mHGSerc5fDt60/WzA5LXkDbpvJP9MMZdMK+ETg802uuVhQLkvQb b8xhStkBnaH18lG11EC7yCoOxolJsQs5DFp25lDF2jEGf+xBC8l3lGGtr7gKFMb0SJ1D EnHBeL9lGeko0rypNJ/EgHDGnyfL/XxE/BUbpv6AzWtqp5oY3/+unJywSgZHrhSSikPT d/Rw== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-wireless-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [23.128.96.18]) by mx.google.com with ESMTP id a10si739692ejr.711.2021.04.09.12.31.30; Fri, 09 Apr 2021 12:31:53 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-wireless-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-wireless-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234761AbhDITbh (ORCPT + 99 others); Fri, 9 Apr 2021 15:31:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38758 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234507AbhDITbg (ORCPT ); Fri, 9 Apr 2021 15:31:36 -0400 Received: from sipsolutions.net (s3.sipsolutions.net [IPv6:2a01:4f8:191:4433::2]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 72A00C061762 for ; Fri, 9 Apr 2021 12:31:22 -0700 (PDT) Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_SECP256R1__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.94) (envelope-from ) id 1lUwqd-009aTJ-Ow; Fri, 09 Apr 2021 21:31:19 +0200 Message-ID: <82a7c6c9bcbe923906276e8aa26a9a783598a0d7.camel@sipsolutions.net> Subject: Re: Memory leak in ieee80211_rx_napi() From: Johannes Berg To: Larry Finger Cc: linux-wireless , Pkshih Date: Fri, 09 Apr 2021 21:31:19 +0200 In-Reply-To: (sfid-20210409_172345_954618_8D29770B) References: (sfid-20210409_172345_954618_8D29770B) Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.38.4 (3.38.4-1.fc33) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-malware-bazaar: not-scanned Precedence: bulk List-ID: X-Mailing-List: linux-wireless@vger.kernel.org Hi Larry, > What setting or lack of, would cause ieee80211_rx_napi() to leak the skb that it > is given? The documentation states that once this call is made, mac80211 owns > this buffer. Does this mean that it will also be freed? Eventually, yes. But it might go onto a NAPI GRO list, etc. Perhaps it might even look like it's leaked if it's on such a list if you didn't implement NAPI properly as polling, but just call ieee80211_rx_napi() with a non-NULL napi struct pointer. That said, of course there might be bugs in mac80211 where it actually leaks the skb. How are you determining that it's being leaked? johannes