[alsa-devel] usb/sound: use-after-free in snd_usb_mixer_interrupt
Hi!
I've got the following report while fuzzing the kernel with syzkaller.
On commit 8a5776a5f49812d29fe4b2d0a2d71675c3facf3f (4.14-rc4).
gadgetfs: bound to dummy_udc driver usb 1-1: new full-speed USB device number 2 using dummy_hcd gadgetfs: connected gadgetfs: disconnected gadgetfs: connected usb 1-1: config 1 has an invalid interface number: 1 but max is 0 usb 1-1: config 1 has 2 interfaces, different from the descriptor's value: 1 usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 0, changing to 10 usb 1-1: too many endpoints for config 1 interface 1 altsetting 174: 131, using maximum allowed: 30 usb 1-1: config 1 interface 1 altsetting 174 has 0 endpoint descriptors, different from the interface de scriptor's value: 131 usb 1-1: config 1 interface 1 has no altsetting 0 usb 1-1: New USB device found, idVendor=0dba, idProduct=1000 usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=252 usb 1-1: SerialNumber: a gadgetfs: configuration #1 hub 1-1:1.0: USB hub found hub 1-1:1.0: config failed, can't read hub descriptor (err -22) snd-usb-audio: probe of 1-1:1.0 failed with error -22 ================================================================== BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 Read of size 8 at addr ffff8800636f8900 by task swapper/1/0
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0-rc4-43418-g43a3f84d2109-dirty #391 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: <IRQ> __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 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 expire_timers kernel/time/timer.c:1320 __run_timers+0x87f/0xd40 kernel/time/timer.c:1620 run_timer_softirq+0x83/0x140 kernel/time/timer.c:1646 __do_softirq+0x2ee/0xc0f kernel/softirq.c:284 invoke_softirq kernel/softirq.c:364 irq_exit+0x171/0x1a0 kernel/softirq.c:405 exiting_irq ./arch/x86/include/asm/apic.h:638 smp_apic_timer_interrupt+0x2b9/0x8d0 arch/x86/kernel/apic/apic.c:1048 apic_timer_interrupt+0x9d/0xb0 </IRQ> RIP: 0010:native_safe_halt+0x6/0x10 ./arch/x86/include/asm/irqflags.h:53 RSP: 0018:ffff88006bac7b90 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff10 RAX: dffffc0000000020 RBX: 1ffff1000d758f76 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff88006baa3a64 RBP: ffff88006bac7b90 R08: ffffffff813d5301 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff1000d758f82 R13: ffff88006bac7cd0 R14: ffffffff8881ecc8 R15: 0000000000000000 arch_safe_halt ./arch/x86/include/asm/paravirt.h:93 default_idle+0x127/0x690 arch/x86/kernel/process.c:341 arch_cpu_idle+0xf/0x20 arch/x86/kernel/process.c:332 default_idle_call+0x3b/0x60 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 do_idle+0x33a/0x410 kernel/sched/idle.c:246 cpu_startup_entry+0x1d/0x20 kernel/sched/idle.c:351 start_secondary+0x3de/0x500 arch/x86/kernel/smpboot.c:278 secondary_startup_64+0xa5/0xa5 arch/x86/kernel/head_64.S:235
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 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
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 kobject_cleanup lib/kobject.c:648 kobject_release lib/kobject.c:677 kref_put ./include/linux/kref.h:70 kobject_put+0x145/0x240 lib/kobject.c:694 put_device+0x25/0x30 drivers/base/core.c:1931 snd_card_free_when_closed sound/core/init.c:489 snd_card_free+0x156/0x220 sound/core/init.c:514 usb_audio_probe+0x1e36/0x2c10 sound/usb/card.c:648 usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932 generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174 usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266 really_probe drivers/base/dd.c:413 driver_probe_device+0x610/0xa00 drivers/base/dd.c:557 __device_attach_driver+0x230/0x290 drivers/base/dd.c:653 bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463 __device_attach+0x26e/0x3d0 drivers/base/dd.c:710 device_initial_probe+0x1f/0x30 drivers/base/dd.c:757 bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523 device_add+0xd0b/0x1660 drivers/base/core.c:1835 usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457 hub_port_connect drivers/usb/core/hub.c:4903 hub_port_connect_change drivers/usb/core/hub.c:5009 port_event drivers/usb/core/hub.c:5115 hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195 process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119 worker_thread+0x221/0x1850 kernel/workqueue.c:2253 kthread+0x3a1/0x470 kernel/kthread.c:231 ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431
The buggy address belongs to the object at ffff8800636f8900 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 0 bytes inside of 192-byte region [ffff8800636f8900, ffff8800636f89c0) The buggy address belongs to the page: page:ffffea00018dbe00 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x100000000000100(slab) raw: 0100000000000100 0000000000000000 0000000000000000 0000000180100010 raw: ffffea00018dbc00 0000000400000004 ffff88006c003380 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff8800636f8800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8800636f8880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
ffff8800636f8900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff8800636f8980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8800636f8a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================
On Mon, 09 Oct 2017 19:50:39 +0200, Andrey Konovalov wrote:
Hi!
I've got the following report while fuzzing the kernel with syzkaller.
On commit 8a5776a5f49812d29fe4b2d0a2d71675c3facf3f (4.14-rc4).
gadgetfs: bound to dummy_udc driver usb 1-1: new full-speed USB device number 2 using dummy_hcd gadgetfs: connected gadgetfs: disconnected gadgetfs: connected usb 1-1: config 1 has an invalid interface number: 1 but max is 0 usb 1-1: config 1 has 2 interfaces, different from the descriptor's value: 1 usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 0, changing to 10 usb 1-1: too many endpoints for config 1 interface 1 altsetting 174: 131, using maximum allowed: 30 usb 1-1: config 1 interface 1 altsetting 174 has 0 endpoint descriptors, different from the interface de scriptor's value: 131 usb 1-1: config 1 interface 1 has no altsetting 0 usb 1-1: New USB device found, idVendor=0dba, idProduct=1000 usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=252 usb 1-1: SerialNumber: a gadgetfs: configuration #1 hub 1-1:1.0: USB hub found hub 1-1:1.0: config failed, can't read hub descriptor (err -22) snd-usb-audio: probe of 1-1:1.0 failed with error -22 ================================================================== BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 Read of size 8 at addr ffff8800636f8900 by task swapper/1/0
A bad news for a sleepless night...
It's a stray URB that isn't properly killed when the usb-audio mixer interface gets the error at probe. The patch below should fix it. I'm going to wrap up with a proper description later.
thanks,
Takashi
--- 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 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
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 */
On Tue, Oct 10, 2017 at 12:10 AM, Takashi Iwai tiwai@suse.de wrote:
On Mon, 09 Oct 2017 19:50:39 +0200, Andrey Konovalov wrote:
Hi!
I've got the following report while fuzzing the kernel with syzkaller.
On commit 8a5776a5f49812d29fe4b2d0a2d71675c3facf3f (4.14-rc4).
gadgetfs: bound to dummy_udc driver usb 1-1: new full-speed USB device number 2 using dummy_hcd gadgetfs: connected gadgetfs: disconnected gadgetfs: connected usb 1-1: config 1 has an invalid interface number: 1 but max is 0 usb 1-1: config 1 has 2 interfaces, different from the descriptor's value: 1 usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 0, changing to 10 usb 1-1: too many endpoints for config 1 interface 1 altsetting 174: 131, using maximum allowed: 30 usb 1-1: config 1 interface 1 altsetting 174 has 0 endpoint descriptors, different from the interface de scriptor's value: 131 usb 1-1: config 1 interface 1 has no altsetting 0 usb 1-1: New USB device found, idVendor=0dba, idProduct=1000 usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=252 usb 1-1: SerialNumber: a gadgetfs: configuration #1 hub 1-1:1.0: USB hub found hub 1-1:1.0: config failed, can't read hub descriptor (err -22) snd-usb-audio: probe of 1-1:1.0 failed with error -22 ================================================================== BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 Read of size 8 at addr ffff8800636f8900 by task swapper/1/0
A bad news for a sleepless night...
It's a stray URB that isn't properly killed when the usb-audio mixer interface gets the error at probe. The patch below should fix it. I'm going to wrap up with a proper description later.
This fixes the crash.
Thanks!
Tested-by: Andrey Konovalov andreyknvl@google.com
thanks,
Takashi
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 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
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 */
On Tue, 10 Oct 2017 13:20:14 +0200, Andrey Konovalov wrote:
On Tue, Oct 10, 2017 at 12:10 AM, Takashi Iwai tiwai@suse.de wrote:
On Mon, 09 Oct 2017 19:50:39 +0200, Andrey Konovalov wrote:
Hi!
I've got the following report while fuzzing the kernel with syzkaller.
On commit 8a5776a5f49812d29fe4b2d0a2d71675c3facf3f (4.14-rc4).
gadgetfs: bound to dummy_udc driver usb 1-1: new full-speed USB device number 2 using dummy_hcd gadgetfs: connected gadgetfs: disconnected gadgetfs: connected usb 1-1: config 1 has an invalid interface number: 1 but max is 0 usb 1-1: config 1 has 2 interfaces, different from the descriptor's value: 1 usb 1-1: config 1 interface 0 altsetting 0 endpoint 0x81 has an invalid bInterval 0, changing to 10 usb 1-1: too many endpoints for config 1 interface 1 altsetting 174: 131, using maximum allowed: 30 usb 1-1: config 1 interface 1 altsetting 174 has 0 endpoint descriptors, different from the interface de scriptor's value: 131 usb 1-1: config 1 interface 1 has no altsetting 0 usb 1-1: New USB device found, idVendor=0dba, idProduct=1000 usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=252 usb 1-1: SerialNumber: a gadgetfs: configuration #1 hub 1-1:1.0: USB hub found hub 1-1:1.0: config failed, can't read hub descriptor (err -22) snd-usb-audio: probe of 1-1:1.0 failed with error -22 ================================================================== BUG: KASAN: use-after-free in snd_usb_mixer_interrupt+0x604/0x6f0 Read of size 8 at addr ffff8800636f8900 by task swapper/1/0
A bad news for a sleepless night...
It's a stray URB that isn't properly killed when the usb-audio mixer interface gets the error at probe. The patch below should fix it. I'm going to wrap up with a proper description later.
This fixes the crash.
Thanks!
Tested-by: Andrey Konovalov andreyknvl@google.com
Thanks, I'll queue the fix to for-linus branch. FWIW, below is the patch with the description.
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] 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: <IRQ> __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 andreyknvl@google.com Tested-by: Andrey Konovalov andreyknvl@google.com Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/usb/mixer.c | 12 ++++++++++-- sound/usb/mixer.h | 2 ++ 2 files changed, 12 insertions(+), 2 deletions(-)
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 @@ int snd_usb_create_mixer(struct snd_usb_audio *chip, int ctrlif,
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 */
participants (2)
-
Andrey Konovalov -
Takashi Iwai