From cb02ffc76a53b5ea751b79b8d4f4d180e5868475 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 9 Oct 2017 14:32:15 +0200 Subject: ALSA: line6: Fix missing initialization before error path The error path in podhd_init() tries to clear the pending timer, while the timer object is initialized at the end of init sequence, thus it may hit the uninitialized object, as spotted by syzkaller: INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 1 PID: 1845 Comm: kworker/1:2 Not tainted 4.14.0-rc2-42613-g1488251d1a98 #238 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: usb_hub_wq hub_event Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x292/0x395 lib/dump_stack.c:52 register_lock_class+0x6c4/0x1a00 kernel/locking/lockdep.c:769 __lock_acquire+0x27e/0x4550 kernel/locking/lockdep.c:3385 lock_acquire+0x259/0x620 kernel/locking/lockdep.c:4002 del_timer_sync+0x12c/0x280 kernel/time/timer.c:1237 podhd_disconnect+0x8c/0x160 sound/usb/line6/podhd.c:299 line6_probe+0x844/0x1310 sound/usb/line6/driver.c:783 podhd_probe+0x64/0x70 sound/usb/line6/podhd.c:474 .... For addressing it, assure the initializations of timer and work by moving them to the beginning of podhd_init(). Fixes: 790869dacc3d ("ALSA: line6: Add support for POD X3") Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Cc: Signed-off-by: Takashi Iwai --- sound/usb/line6/podhd.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) (limited to 'sound/usb') diff --git a/sound/usb/line6/podhd.c b/sound/usb/line6/podhd.c index 956f847a96e4..14ab82ea7e82 100644 --- a/sound/usb/line6/podhd.c +++ b/sound/usb/line6/podhd.c @@ -317,6 +317,9 @@ static int podhd_init(struct usb_line6 *line6, line6->disconnect = podhd_disconnect; + init_timer(&pod->startup_timer); + INIT_WORK(&pod->startup_work, podhd_startup_workqueue); + if (pod->line6.properties->capabilities & LINE6_CAP_CONTROL) { /* claim the data interface */ intf = usb_ifnum_to_if(line6->usbdev, @@ -358,8 +361,6 @@ static int podhd_init(struct usb_line6 *line6, } /* init device and delay registering */ - init_timer(&pod->startup_timer); - INIT_WORK(&pod->startup_work, podhd_startup_workqueue); podhd_startup(pod); return 0; } -- cgit v1.2.3 From 54a4b2b45817ea2365b40c923c098a26af0c0dbb Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 9 Oct 2017 14:26:27 +0200 Subject: ALSA: line6: Fix NULL dereference at podhd_disconnect() When podhd_init() failed with the acquiring a ctrl i/f, the line6 helper still calls the disconnect callback that eventually calls again usb_driver_release_interface() with the NULL intf. Put the proper NULL check before calling it for avoiding an Oops. Fixes: fc90172ba283 ("ALSA: line6: Claim pod x3 usb data interface") Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Cc: Signed-off-by: Takashi Iwai --- sound/usb/line6/podhd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'sound/usb') diff --git a/sound/usb/line6/podhd.c b/sound/usb/line6/podhd.c index 14ab82ea7e82..451007c27743 100644 --- a/sound/usb/line6/podhd.c +++ b/sound/usb/line6/podhd.c @@ -301,7 +301,8 @@ static void podhd_disconnect(struct usb_line6 *line6) intf = usb_ifnum_to_if(line6->usbdev, pod->line6.properties->ctrl_if); - usb_driver_release_interface(&podhd_driver, intf); + if (intf) + usb_driver_release_interface(&podhd_driver, intf); } } -- cgit v1.2.3 From c95072b3d88fac4be295815f2b67df366c0c297f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Mon, 9 Oct 2017 14:51:23 +0200 Subject: ALSA: line6: Fix leftover URB at error-path during probe While line6_probe() may kick off URB for a control MIDI endpoint, the function doesn't clean up it properly at its error path. This results in a leftover URB action that is eventually triggered later and causes an Oops like: general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 0 Comm: swapper/1 Not tainted RIP: 0010:usb_fill_bulk_urb ./include/linux/usb.h:1619 RIP: 0010:line6_start_listen+0x3fe/0x9e0 sound/usb/line6/driver.c:76 Call Trace: line6_data_received+0x1f7/0x470 sound/usb/line6/driver.c:326 __usb_hcd_giveback_urb+0x2e0/0x650 drivers/usb/core/hcd.c:1779 usb_hcd_giveback_urb+0x337/0x420 drivers/usb/core/hcd.c:1845 dummy_timer+0xba9/0x39f0 drivers/usb/gadget/udc/dummy_hcd.c:1965 call_timer_fn+0x2a2/0x940 kernel/time/timer.c:1281 .... Since the whole clean-up procedure is done in line6_disconnect() callback, we can simply call it in the error path instead of open-coding the whole again. It'll fix such an issue automagically. The bug was spotted by syzkaller. Fixes: eedd0e95d355 ("ALSA: line6: Don't forget to call driver's destructor at error path") Reported-by: Andrey Konovalov Tested-by: Andrey Konovalov Cc: Signed-off-by: Takashi Iwai --- sound/usb/line6/driver.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) (limited to 'sound/usb') diff --git a/sound/usb/line6/driver.c b/sound/usb/line6/driver.c index 0ff5a7d2e19f..c8f723c3a033 100644 --- a/sound/usb/line6/driver.c +++ b/sound/usb/line6/driver.c @@ -779,9 +779,10 @@ int line6_probe(struct usb_interface *interface, return 0; error: - if (line6->disconnect) - line6->disconnect(line6); - snd_card_free(card); + /* we can call disconnect callback here because no close-sync is + * needed yet at this point + */ + line6_disconnect(interface); return ret; } EXPORT_SYMBOL_GPL(line6_probe); -- cgit v1.2.3 From 124751d5e63c823092060074bd0abaae61aaa9c4 Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Tue, 10 Oct 2017 14:10:32 +0200 Subject: ALSA: usb-audio: Kill stray URB at exiting 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 --- sound/usb/mixer.c | 12 ++++++++++-- sound/usb/mixer.h | 2 ++ 2 files changed, 12 insertions(+), 2 deletions(-) (limited to 'sound/usb') diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c index 9732edf77f86..91bc8f18791e 100644 --- a/sound/usb/mixer.c +++ b/sound/usb/mixer.c @@ -2234,6 +2234,9 @@ 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); @@ -2584,8 +2587,13 @@ _error: void snd_usb_mixer_disconnect(struct usb_mixer_interface *mixer) { - 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; } #ifdef CONFIG_PM diff --git a/sound/usb/mixer.h b/sound/usb/mixer.h index 2b4b067646ab..545d99b09706 100644 --- a/sound/usb/mixer.h +++ b/sound/usb/mixer.h @@ -22,6 +22,8 @@ struct usb_mixer_interface { struct urb *rc_urb; struct usb_ctrlrequest *rc_setup_packet; u8 rc_buffer[6]; + + bool disconnected; }; #define MAX_CHANNELS 16 /* max logical channels */ -- cgit v1.2.3 From 99fee508245825765ff60155fed43f970ff83a8f Mon Sep 17 00:00:00 2001 From: Takashi Iwai Date: Wed, 11 Oct 2017 16:39:02 +0200 Subject: ALSA: caiaq: Fix stray URB at probe error path caiaq driver doesn't kill the URB properly at its error path during the probe, which may lead to a use-after-free error later. This patch addresses it. Reported-by: Johan Hovold Reviewed-by: Johan Hovold Cc: Signed-off-by: Takashi Iwai --- sound/usb/caiaq/device.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) (limited to 'sound/usb') diff --git a/sound/usb/caiaq/device.c b/sound/usb/caiaq/device.c index 0fb6b1b79261..d8409d9ae55b 100644 --- a/sound/usb/caiaq/device.c +++ b/sound/usb/caiaq/device.c @@ -469,10 +469,12 @@ static int init_card(struct snd_usb_caiaqdev *cdev) err = snd_usb_caiaq_send_command(cdev, EP1_CMD_GET_DEVICE_INFO, NULL, 0); if (err) - return err; + goto err_kill_urb; - if (!wait_event_timeout(cdev->ep1_wait_queue, cdev->spec_received, HZ)) - return -ENODEV; + if (!wait_event_timeout(cdev->ep1_wait_queue, cdev->spec_received, HZ)) { + err = -ENODEV; + goto err_kill_urb; + } usb_string(usb_dev, usb_dev->descriptor.iManufacturer, cdev->vendor_name, CAIAQ_USB_STR_LEN); @@ -507,6 +509,10 @@ static int init_card(struct snd_usb_caiaqdev *cdev) setup_card(cdev); return 0; + + err_kill_urb: + usb_kill_urb(&cdev->ep1_in_urb); + return err; } static int snd_probe(struct usb_interface *intf, -- cgit v1.2.3