From patchwork Wed Aug 4 11:03:02 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Desmond Cheong Zhi Xi X-Patchwork-Id: 12418583 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 87C4BC4338F for ; Wed, 4 Aug 2021 11:03:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 577CD61040 for ; Wed, 4 Aug 2021 11:03:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237716AbhHDLDw (ORCPT ); Wed, 4 Aug 2021 07:03:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35830 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235764AbhHDLDv (ORCPT ); Wed, 4 Aug 2021 07:03:51 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7073EC061799; Wed, 4 Aug 2021 04:03:38 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id a20so2655854plm.0; Wed, 04 Aug 2021 04:03:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jwMjX9uKOX34bxHroGHlO+KGwPb8TW7nGHLpbS6oqzs=; b=aWH8FPQcF8fQhUjm6O6pl9YL1byqoTvc6uU8AhtNMeTd3lIAGuZ25KPl6MaM9FpcYg AK72GH7TbKLvTXOMi4bnhw6zIlMm8Kx6ogrRfFOc+nwM+/I6c665iHHH+STgum4xFhUC pN6hTal3G3Fj1RZKfX4RW3kuk7DfkGgnS/rgwqjyfxmqwX1JXbkFHYfoaCpN+nJP4oNk d4g39isClzgBy70grsZ4r3rizQnGgZOhAh+6BFUus/Q5ACrgoYviYj1glJEeQmpuzml9 UVE4iAb3aY2t88ryjV6Mqvn44EzuXlMttt9Nn9fMW68uxyHNpxw+vhQTDkcNvxz20pfa AP1w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=jwMjX9uKOX34bxHroGHlO+KGwPb8TW7nGHLpbS6oqzs=; b=cC0mVDB/hLu8oT5S/vl3MkBc988krMQMq1fWGzUKMDREI8Ru7u5EcP31nhyrn2A3V5 PeQ0/N1Lg1m9Wl6zRasSNtjAel0G/M9vGGRhJdwEdwsGWbfOsAHlIS1OrY65fKEup4J0 2z9K26SKGnNzOBtaKRu8M0kgU1eOAO/sBWfGbNFBFws7u/RoF+3erwJltkAd2R6gFlqY OnSCpL334Z7kAX6JqbT1xcskxCFrWnst+hRk27jDKPBNwmTAL7X9i+7OMJRblc6Rg72D z1Y/uwbLPYhD5xw0brul25sB0GKvgzApAX9EthbTf2G8vksTAr5zAIqqtMF3dt7Szc3d 54ew== X-Gm-Message-State: AOAM5336K0LrctiY017/xaOfAzG5vqsZ/n6gVNRXy6K2ogJUxeLiddR5 0Bf8LHdtIWCcgfCOPSNiRjONYvB0s0chEiyHGg0= X-Google-Smtp-Source: ABdhPJxkL6C5JVgPh+WmVxXS7CD5vAKQHOzGQMgYJ68HC5d8vmswPnC0kPLsa24Tquu4MnmcgF4YGA== X-Received: by 2002:aa7:804f:0:b029:334:4951:da88 with SMTP id y15-20020aa7804f0000b02903344951da88mr26922729pfm.29.1628075017777; Wed, 04 Aug 2021 04:03:37 -0700 (PDT) Received: from localhost.localdomain ([118.200.190.93]) by smtp.gmail.com with ESMTPSA id k4sm2206147pjs.55.2021.08.04.04.03.33 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 04 Aug 2021 04:03:37 -0700 (PDT) From: Desmond Cheong Zhi Xi To: marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com, davem@davemloft.net, kuba@kernel.org, sudipm.mukherjee@gmail.com Cc: Desmond Cheong Zhi Xi , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, linux-kernel-mentees@lists.linuxfoundation.org Subject: [PATCH v5 0/6] Bluetooth: fix locking and socket killing in SCO and RFCOMM Date: Wed, 4 Aug 2021 19:03:02 +0800 Message-Id: <20210804110308.910744-1-desmondcheongzx@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Hi, This patch series started out as a fix for "inconsistent lock state in sco_sock_timeout" reported by Syzbot [1]. Patch 1 is sufficient to fix this error. This was also confirmed by the reproducer for "BUG: corrupted list in kobject_add_internal (3)" [2] which consistently hits the inconsistent lock state error. However, while testing the proposed fix, the reproducer for [1] would randomly return a human-unreadable error [3]. After further investigation, this bug seems to be caused by an unrelated error with forking [4]. While trying to fix the mysterious error, additional fixes were added, such as switching to lock_sock and serializing _{set,clear}_timer. Additionally, as the reproducer kept hitting the oom-killer, a fix for SCO socket killing was also added. The reproducer for [1] was robust enough to catch errors with these additional fixes, hence all the patches in this series were squashed then tested with the reproducer for [1]. Overall, this series makes the following changes: - Patch 1: Schedule SCO sock timeouts with delayed_work to avoid inconsistent lock usage (removes SOFTIRQs from SCO) - Patch 2: Avoid a circular dependency between hci_dev_lock and lock_sock (enables the switch to lock_sock) - Patch 3: Switch to lock_sock in SCO now that SOFTIRQs and potential deadlocks are removed - Patch 4: Serialize calls to sco_sock_{set,clear}_timer - Patch 5: Switch to lock_sock in RFCOMM - Patch 6: fix SCO socket killing v4 -> v5: - Renamed the delayed_work variable, moved checks for sco_pi(sk)->conn into sco_sock_{clear,set}_timer, as suggested by Luiz Augusto von Dentz and Marcel Holtmann. - Added check for conn->sk in sco_sock_timeout, accompanied by a sock_hold to avoid UAF errors. - Added check to flush work items before freeing conn. - Avoid a circular dependency between hci_dev_lock and lock_sock. - Switch to lock_sock in SCO, as suggested by Marcel Holtmann. - Serial calls to sco_sock_{set,clear}_timer. - Switch to lock_sock in RFCOMM, as suggested by Marcel Holtmann. - Add a fix for SCO socket killing. v3 -> v4: - Switch to using delayed_work to schedule SCO sock timeouts instead of using local_bh_disable. As suggested by Luiz Augusto von Dentz. v2 -> v3: - Split SCO and RFCOMM code changes, as suggested by Luiz Augusto von Dentz. - Simplify local bh disabling in SCO by using local_bh_disable/enable inside sco_chan_del since local_bh_disable/enable pairs are reentrant. v1 -> v2: - Instead of pulling out the clean-up code out from sco_chan_del and using it directly in sco_conn_del, disable local softirqs for relevant sections. - Disable local softirqs more thoroughly for instances of bh_lock_sock/bh_lock_sock_nested in the bluetooth subsystem. Specifically, the calls in af_bluetooth.c and rfcomm/sock.c are now made with local softirqs disabled as well. Link: https://syzkaller.appspot.com/bug?id=9089d89de0502e120f234ca0fc8a703f7368b31e [1] Link: https://syzkaller.appspot.com/bug?extid=66264bf2fd0476be7e6c [2] Link: https://syzkaller.appspot.com/text?tag=CrashReport&x=172d819a300000 [3] Link: https://syzkaller.appspot.com/bug?id=e1bf7ba90d8dafcf318666192aba1cfd65507377 [4] Best wishes, Desmond Desmond Cheong Zhi Xi (6): Bluetooth: schedule SCO timeouts with delayed_work Bluetooth: avoid circular locks in sco_sock_connect Bluetooth: switch to lock_sock in SCO Bluetooth: serialize calls to sco_sock_{set,clear}_timer Bluetooth: switch to lock_sock in RFCOMM Bluetooth: fix repeated calls to sco_sock_kill net/bluetooth/rfcomm/sock.c | 8 +-- net/bluetooth/sco.c | 107 +++++++++++++++++++++--------------- 2 files changed, 66 insertions(+), 49 deletions(-)