From mboxrd@z Thu Jan 1 00:00:00 1970 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=-4.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=unavailable 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 B8228C43218 for ; Sat, 27 Apr 2019 15:27:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8DC23208CA for ; Sat, 27 Apr 2019 15:27:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728527AbfD0P1P (ORCPT ); Sat, 27 Apr 2019 11:27:15 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:33206 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727391AbfD0PPY (ORCPT ); Sat, 27 Apr 2019 11:15:24 -0400 Received: from [192.168.4.242] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1hKP2t-0000zO-BW; Sat, 27 Apr 2019 16:15:19 +0100 Received: from ben by deadeye with local (Exim 4.92) (envelope-from ) id 1hKP2n-0004e9-U2; Sat, 27 Apr 2019 16:15:13 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Mauro Carvalho Chehab" , "Matthias Schwarzott" Date: Sat, 27 Apr 2019 16:13:09 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 186/202] media: em28xx: Fix use-after-free when disconnecting In-Reply-To: X-SA-Exim-Connect-IP: 192.168.4.242 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.66-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Matthias Schwarzott commit 910b0797fa9e8af09c44a3fa36cb310ba7a7218d upstream. Fix bug by moving the i2c_unregister_device calls after deregistration of dvb frontend. The new style i2c drivers already destroys the frontend object at i2c_unregister_device time. When the dvb frontend is unregistered afterwards it leads to this oops: [ 6058.866459] BUG: unable to handle kernel NULL pointer dereference at 00000000000001f8 [ 6058.866578] IP: dvb_frontend_stop+0x30/0xd0 [dvb_core] [ 6058.866644] PGD 0 [ 6058.866646] P4D 0 [ 6058.866726] Oops: 0000 [#1] SMP [ 6058.866768] Modules linked in: rc_pinnacle_pctv_hd(O) em28xx_rc(O) si2157(O) si2168(O) em28xx_dvb(O) em28xx(O) si2165(O) a8293(O) tda10071(O) tea5767(O) tuner(O) cx23885(O) tda18271(O) videobuf2_dvb(O) videobuf2_dma_sg(O) m88ds3103(O) tveeprom(O) cx2341x(O) v4l2_common(O) dvb_core(O) rc_core(O) videobuf2_memops(O) videobuf2_v4l2(O) videobuf2_core(O) videodev(O) media(O) bluetooth ecdh_generic ums_realtek uas rtl8192cu rtl_usb rtl8192c_common rtlwifi usb_storage snd_hda_codec_realtek snd_hda_codec_hdmi snd_hda_codec_generic i2c_mux snd_hda_intel snd_hda_codec snd_hwdep x86_pkg_temp_thermal snd_hda_core kvm_intel kvm irqbypass [last unloaded: videobuf2_memops] [ 6058.867497] CPU: 2 PID: 7349 Comm: kworker/2:0 Tainted: G W O 4.13.9-gentoo #1 [ 6058.867595] Hardware name: MEDION E2050 2391/H81H3-EM2, BIOS H81EM2W08.308 08/25/2014 [ 6058.867692] Workqueue: usb_hub_wq hub_event [ 6058.867746] task: ffff88011a15e040 task.stack: ffffc90003074000 [ 6058.867825] RIP: 0010:dvb_frontend_stop+0x30/0xd0 [dvb_core] [ 6058.867896] RSP: 0018:ffffc90003077b58 EFLAGS: 00010293 [ 6058.867964] RAX: 0000000000000000 RBX: 0000000000000000 RCX: 000000010040001f [ 6058.868056] RDX: ffff88011a15e040 RSI: ffffea000464e400 RDI: ffff88001cbe3028 [ 6058.868150] RBP: ffffc90003077b68 R08: ffff880119390380 R09: 000000010040001f [ 6058.868241] R10: ffffc90003077b18 R11: 000000000001e200 R12: ffff88001cbe3028 [ 6058.868330] R13: ffff88001cbe68d0 R14: ffff8800cf734000 R15: ffff8800cf734098 [ 6058.868419] FS: 0000000000000000(0000) GS:ffff88011fb00000(0000) knlGS:0000000000000000 [ 6058.868511] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 6058.868578] CR2: 00000000000001f8 CR3: 00000001113c5000 CR4: 00000000001406e0 [ 6058.868662] Call Trace: [ 6058.868705] dvb_unregister_frontend+0x2a/0x80 [dvb_core] [ 6058.868774] em28xx_dvb_fini+0x132/0x220 [em28xx_dvb] [ 6058.868840] em28xx_close_extension+0x34/0x90 [em28xx] [ 6058.868902] em28xx_usb_disconnect+0x4e/0x70 [em28xx] [ 6058.868968] usb_unbind_interface+0x6d/0x260 [ 6058.869025] device_release_driver_internal+0x150/0x210 [ 6058.869094] device_release_driver+0xd/0x10 [ 6058.869150] bus_remove_device+0xe4/0x160 [ 6058.869204] device_del+0x1ce/0x2f0 [ 6058.869253] usb_disable_device+0x99/0x270 [ 6058.869306] usb_disconnect+0x8d/0x260 [ 6058.869359] hub_event+0x93d/0x1520 [ 6058.869408] ? dequeue_task_fair+0xae5/0xd20 [ 6058.869467] process_one_work+0x1d9/0x3e0 [ 6058.869522] worker_thread+0x43/0x3e0 [ 6058.869576] kthread+0x104/0x140 [ 6058.869602] ? trace_event_raw_event_workqueue_work+0x80/0x80 [ 6058.869640] ? kthread_create_on_node+0x40/0x40 [ 6058.869673] ret_from_fork+0x22/0x30 [ 6058.869698] Code: 54 49 89 fc 53 48 8b 9f 18 03 00 00 0f 1f 44 00 00 41 83 bc 24 04 05 00 00 02 74 0c 41 c7 84 24 04 05 00 00 01 00 00 00 0f ae f0 <48> 8b bb f8 01 00 00 48 85 ff 74 5c e8 df 40 f0 e0 48 8b 93 f8 [ 6058.869850] RIP: dvb_frontend_stop+0x30/0xd0 [dvb_core] RSP: ffffc90003077b58 [ 6058.869894] CR2: 00000000000001f8 [ 6058.875880] ---[ end trace 717eecf7193b3fc6 ]--- Signed-off-by: Matthias Schwarzott Signed-off-by: Mauro Carvalho Chehab [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- drivers/media/usb/em28xx/em28xx-dvb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/drivers/media/usb/em28xx/em28xx-dvb.c +++ b/drivers/media/usb/em28xx/em28xx-dvb.c @@ -1651,6 +1651,8 @@ static int em28xx_dvb_fini(struct em28xx prevent_sleep(&dvb->fe[1]->ops); } + em28xx_unregister_dvb(dvb); + /* remove I2C tuner */ if (client) { module_put(client->dev.driver->owner); @@ -1664,7 +1666,6 @@ static int em28xx_dvb_fini(struct em28xx i2c_unregister_device(client); } - em28xx_unregister_dvb(dvb); kfree(dvb); dev->dvb = NULL; kref_put(&dev->ref, em28xx_free_device);