From patchwork Tue Jul 10 14:58:29 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Paolo Pisati X-Patchwork-Id: 942025 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=lists.ubuntu.com (client-ip=91.189.94.19; helo=huckleberry.canonical.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=canonical.com Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 41Q51Y0zxyz9s1b; Wed, 11 Jul 2018 00:58:40 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.86_2) (envelope-from ) id 1fcu64-0000l1-Qh; Tue, 10 Jul 2018 14:58:32 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.86_2) (envelope-from ) id 1fcu62-0000kZ-CQ for kernel-team@lists.ubuntu.com; Tue, 10 Jul 2018 14:58:30 +0000 Received: from 1.general.ppisati.uk.vpn ([10.172.193.134] helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.76) (envelope-from ) id 1fcu62-0006h9-3W for kernel-team@lists.ubuntu.com; Tue, 10 Jul 2018 14:58:30 +0000 From: Paolo Pisati To: kernel-team@lists.ubuntu.com Subject: [PATCH] ALSA: usb-audio: Kill stray URB at exiting Date: Tue, 10 Jul 2018 16:58:29 +0200 Message-Id: <1531234709-6783-2-git-send-email-paolo.pisati@canonical.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1531234709-6783-1-git-send-email-paolo.pisati@canonical.com> References: <1531234709-6783-1-git-send-email-paolo.pisati@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Takashi Iwai USB-audio driver may leave a stray URB for the mixer interrupt when it exits by some error during probe. This leads to a use-after-free error as spotted by syzkaller like: ================================================================== BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 print_address_description+0x78/0x280 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 kasan_report+0x23d/0x350 mm/kasan/report.c:409 __asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430 snd_usb_mixer_interrupt+0x604/0x6f0 sound/usb/mixer.c:2490 __usb_hcd_giveback_urb+0x2e0/0x650 drivers/usb/core/hcd.c:1779 .... Allocated by task 1484: save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551 kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772 kmalloc ./include/linux/slab.h:493 kzalloc ./include/linux/slab.h:666 snd_usb_create_mixer+0x145/0x1010 sound/usb/mixer.c:2540 create_standard_mixer_quirk+0x58/0x80 sound/usb/quirks.c:516 snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560 create_composite_quirk+0x1c4/0x3e0 sound/usb/quirks.c:59 snd_usb_create_quirk+0x92/0x100 sound/usb/quirks.c:560 usb_audio_probe+0x1040/0x2c10 sound/usb/card.c:618 .... Freed by task 1484: save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1390 slab_free_freelist_hook mm/slub.c:1412 slab_free mm/slub.c:2988 kfree+0xf6/0x2f0 mm/slub.c:3919 snd_usb_mixer_free+0x11a/0x160 sound/usb/mixer.c:2244 snd_usb_mixer_dev_free+0x36/0x50 sound/usb/mixer.c:2250 __snd_device_free+0x1ff/0x380 sound/core/device.c:91 snd_device_free_all+0x8f/0xe0 sound/core/device.c:244 snd_card_do_free sound/core/init.c:461 release_card_device+0x47/0x170 sound/core/init.c:181 device_release+0x13f/0x210 drivers/base/core.c:814 .... Actually such a URB is killed properly at disconnection when the device gets probed successfully, and what we need is to apply it for the error-path, too. In this patch, we apply snd_usb_mixer_disconnect() at releasing. Also introduce a new flag, disconnected, to struct usb_mixer_interface for not performing the disconnection procedure twice. Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Cc: Signed-off-by: Takashi Iwai (cherry picked from commit 124751d5e63c823092060074bd0abaae61aaa9c4) Signed-off-by: Paolo Pisati Acked-by: Stefan Bader Signed-off-by: Juerg Haefliger --- sound/usb/card.c | 5 ++++- sound/usb/mixer.c | 17 +++++++++++------ sound/usb/mixer.h | 4 +++- 3 files changed, 18 insertions(+), 8 deletions(-) diff --git a/sound/usb/card.c b/sound/usb/card.c index ab433a0..abd816d 100644 --- a/sound/usb/card.c +++ b/sound/usb/card.c @@ -616,7 +616,10 @@ static void snd_usb_audio_disconnect(struct usb_device *dev, } /* release mixer resources */ list_for_each(p, &chip->mixer_list) { - snd_usb_mixer_disconnect(p); + struct usb_mixer_interface *mixer; + + mixer = list_entry(p, struct usb_mixer_interface, list); + snd_usb_mixer_disconnect(mixer); } } diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 43492a6..b369c46 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -2071,6 +2071,9 @@ static int parse_audio_unit(struct mixer_build *state, int unitid) static void snd_usb_mixer_free(struct usb_mixer_interface *mixer) { + /* kill pending URBs */ + snd_usb_mixer_disconnect(mixer); + kfree(mixer->id_elems); if (mixer->urb) { kfree(mixer->urb->transfer_buffer); @@ -2412,11 +2415,13 @@ _error: return err; } -void snd_usb_mixer_disconnect(struct list_head *p) +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer) { - struct usb_mixer_interface *mixer; - - mixer = list_entry(p, struct usb_mixer_interface, list); - usb_kill_urb(mixer->urb); - usb_kill_urb(mixer->rc_urb); + if (mixer->disconnected) + return; + if (mixer->urb) + usb_kill_urb(mixer->urb); + if (mixer->rc_urb) + usb_kill_urb(mixer->rc_urb); + mixer->disconnected = true; } diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h index aab80df..f74a4d6 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -23,6 +23,8 @@ struct usb_mixer_interface { u8 audigy2nx_leds[3]; u8 xonar_u1_status; + + bool disconnected; }; #define MAX_CHANNELS 16 /* max logical channels */ @@ -57,7 +59,7 @@ struct usb_mixer_elem_info { int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif, int ignore_error); -void snd_usb_mixer_disconnect(struct list_head *p); +void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer); void snd_usb_mixer_notify_id(struct usb_mixer_interface *mixer, int unitid);