From patchwork Wed May 13 10:31:55 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Imre Deak X-Patchwork-Id: 225909 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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, 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 71AF5CA90AF for ; Wed, 13 May 2020 10:32:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 51B39206CC for ; Wed, 13 May 2020 10:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727794AbgEMKck (ORCPT ); Wed, 13 May 2020 06:32:40 -0400 Received: from mga09.intel.com ([134.134.136.24]:63390 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732556AbgEMKcj (ORCPT ); Wed, 13 May 2020 06:32:39 -0400 IronPort-SDR: 0sT9FsNGn+ZoyqUjwScFX5GJusHUoEX2j+im6z+zZbk+xBCvj0qCa/Afrvjbijn4g6jc3/TFRu Mz0AKgNuIIBA== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 May 2020 03:32:38 -0700 IronPort-SDR: Hvv4InNJGc7fHnyB8SLK88DtnDdJpIDRTXFIvd/L4yRlczBHHJmc8srE4vV6AEx2BLRfvbzlry 2uaQo/yz9Kmg== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,387,1583222400"; d="scan'208";a="262438024" Received: from ideak-desk.fi.intel.com ([10.237.72.183]) by orsmga003.jf.intel.com with ESMTP; 13 May 2020 03:32:36 -0700 From: Imre Deak To: intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org Cc: Lyude Paul , Sean Paul , Wayne Lin , stable@vger.kernel.org Subject: [PATCH] drm/dp_mst: Fix timeout handling of MST down messages Date: Wed, 13 May 2020 13:31:55 +0300 Message-Id: <20200513103155.12336-1-imre.deak@intel.com> X-Mailer: git-send-email 2.23.1 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org This fixes the following use-after-free problem in case an MST down message times out, while waiting for the response for it: [ 449.022841] [drm:drm_dp_mst_wait_tx_reply.isra.26] timedout msg send 0000000080ba7fa2 2 0 [ 449.022898] ------------[ cut here ]------------ [ 449.022903] list_add corruption. prev->next should be next (ffff88847dae32c0), but was 6b6b6b6b6b6b6b6b. (prev=ffff88847db1c140). [ 449.022931] WARNING: CPU: 2 PID: 22 at lib/list_debug.c:28 __list_add_valid+0x4d/0x70 [ 449.022935] Modules linked in: asix usbnet mii snd_hda_codec_hdmi mei_hdcp i915 x86_pkg_temp_thermal coretemp crct10dif_pclmul crc32_pclmul ghash_clmulni_intel snd_hda_intel snd_intel_dspcfg snd_hda_codec snd_hwdep e1000e snd_hda_core ptp snd_pcm pps_core mei_me mei intel_lpss_pci prime_numbers [ 449.022966] CPU: 2 PID: 22 Comm: kworker/2:0 Not tainted 5.7.0-rc3-CI-Patchwork_17536+ #1 [ 449.022970] Hardware name: Intel Corporation Tiger Lake Client Platform/TigerLake U DDR4 SODIMM RVP, BIOS TGLSFWI1.R00.2457.A16.1912270059 12/27/2019 [ 449.022976] Workqueue: events_long drm_dp_mst_link_probe_work [ 449.022982] RIP: 0010:__list_add_valid+0x4d/0x70 [ 449.022987] Code: c3 48 89 d1 48 c7 c7 f0 e7 32 82 48 89 c2 e8 3a 49 b7 ff 0f 0b 31 c0 c3 48 89 c1 4c 89 c6 48 c7 c7 40 e8 32 82 e8 23 49 b7 ff <0f> 0b 31 c0 c3 48 89 f2 4c 89 c1 48 89 fe 48 c7 c7 90 e8 32 82 e8 [ 449.022991] RSP: 0018:ffffc900001abcb0 EFLAGS: 00010286 [ 449.022995] RAX: 0000000000000000 RBX: ffff88847dae2d58 RCX: 0000000000000001 [ 449.022999] RDX: 0000000080000001 RSI: ffff88849d914978 RDI: 00000000ffffffff [ 449.023002] RBP: ffff88847dae32c0 R08: ffff88849d914978 R09: 0000000000000000 [ 449.023006] R10: ffffc900001abcb8 R11: 0000000000000000 R12: ffff888490d98400 [ 449.023009] R13: ffff88847dae3230 R14: ffff88847db1c140 R15: ffff888490d98540 [ 449.023013] FS: 0000000000000000(0000) GS:ffff88849ff00000(0000) knlGS:0000000000000000 [ 449.023017] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 449.023021] CR2: 00007fb96fafdc63 CR3: 0000000005610004 CR4: 0000000000760ee0 [ 449.023025] PKRU: 55555554 [ 449.023028] Call Trace: [ 449.023034] drm_dp_queue_down_tx+0x59/0x110 [ 449.023041] ? rcu_read_lock_sched_held+0x4d/0x80 [ 449.023050] ? kmem_cache_alloc_trace+0x2a6/0x2d0 [ 449.023060] drm_dp_send_link_address+0x74/0x870 [ 449.023065] ? __slab_free+0x3e1/0x5c0 [ 449.023071] ? lockdep_hardirqs_on+0xe0/0x1c0 [ 449.023078] ? lockdep_hardirqs_on+0xe0/0x1c0 [ 449.023097] drm_dp_check_and_send_link_address+0x9a/0xc0 [ 449.023106] drm_dp_mst_link_probe_work+0x9e/0x160 [ 449.023117] process_one_work+0x268/0x600 [ 449.023124] ? __schedule+0x307/0x8d0 [ 449.023139] worker_thread+0x37/0x380 [ 449.023149] ? process_one_work+0x600/0x600 [ 449.023153] kthread+0x140/0x160 [ 449.023159] ? kthread_park+0x80/0x80 [ 449.023169] ret_from_fork+0x24/0x50 Fixes: d308a881a591 ("drm/dp_mst: Kill the second sideband tx slot, save the world") Cc: Lyude Paul Cc: Sean Paul Cc: Wayne Lin Cc: # v3.17+ Signed-off-by: Imre Deak --- drivers/gpu/drm/drm_dp_mst_topology.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_dp_mst_topology.c b/drivers/gpu/drm/drm_dp_mst_topology.c index 2d4132e0a98f..70455e304a26 100644 --- a/drivers/gpu/drm/drm_dp_mst_topology.c +++ b/drivers/gpu/drm/drm_dp_mst_topology.c @@ -1197,7 +1197,8 @@ static int drm_dp_mst_wait_tx_reply(struct drm_dp_mst_branch *mstb, /* remove from q */ if (txmsg->state == DRM_DP_SIDEBAND_TX_QUEUED || - txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND) + txmsg->state == DRM_DP_SIDEBAND_TX_START_SEND || + txmsg->state == DRM_DP_SIDEBAND_TX_SENT) list_del(&txmsg->next); } out: