* usb/sound: use-after-free in snd_usb_mixer_interrupt
@ 2017-10-09 17:50 Andrey Konovalov
2017-10-09 22:10 ` Takashi Iwai
0 siblings, 1 reply; 6+ messages in thread
From: Andrey Konovalov @ 2017-10-09 17:50 UTC (permalink / raw)
To: Jaroslav Kysela, Takashi Iwai, Bhumika Goyal, Con Kolivas,
Stephen Barber, alsa-devel, LKML
Cc: Dmitry Vyukov, Kostya Serebryany, syzkaller
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
==================================================================
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: usb/sound: use-after-free in snd_usb_mixer_interrupt
2017-10-09 17:50 usb/sound: use-after-free in snd_usb_mixer_interrupt Andrey Konovalov
@ 2017-10-09 22:10 ` Takashi Iwai
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2017-10-09 22:10 UTC (permalink / raw)
To: Andrey Konovalov
Cc: alsa-devel, Stephen Barber, Bhumika Goyal, Con Kolivas,
Jaroslav Kysela, LKML, Dmitry Vyukov, Kostya Serebryany,
syzkaller
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 */
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: usb/sound: use-after-free in snd_usb_mixer_interrupt
@ 2017-10-09 22:10 ` Takashi Iwai
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2017-10-09 22:10 UTC (permalink / raw)
To: Andrey Konovalov
Cc: alsa-devel, Con Kolivas, LKML, Kostya Serebryany, syzkaller,
Dmitry Vyukov, Stephen Barber, Bhumika Goyal
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 */
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: usb/sound: use-after-free in snd_usb_mixer_interrupt
2017-10-09 22:10 ` Takashi Iwai
(?)
@ 2017-10-10 11:20 ` Andrey Konovalov
2017-10-10 12:19 ` Takashi Iwai
-1 siblings, 1 reply; 6+ messages in thread
From: Andrey Konovalov @ 2017-10-10 11:20 UTC (permalink / raw)
To: Takashi Iwai
Cc: alsa-devel, Stephen Barber, Bhumika Goyal, Con Kolivas,
Jaroslav Kysela, LKML, Dmitry Vyukov, Kostya Serebryany,
syzkaller
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 */
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: usb/sound: use-after-free in snd_usb_mixer_interrupt
2017-10-10 11:20 ` Andrey Konovalov
@ 2017-10-10 12:19 ` Takashi Iwai
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2017-10-10 12:19 UTC (permalink / raw)
To: Andrey Konovalov
Cc: alsa-devel, Stephen Barber, Bhumika Goyal, Con Kolivas,
Jaroslav Kysela, LKML, Dmitry Vyukov, Kostya Serebryany,
syzkaller
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 */
--
2.14.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: usb/sound: use-after-free in snd_usb_mixer_interrupt
@ 2017-10-10 12:19 ` Takashi Iwai
0 siblings, 0 replies; 6+ messages in thread
From: Takashi Iwai @ 2017-10-10 12:19 UTC (permalink / raw)
To: Andrey Konovalov
Cc: alsa-devel, Con Kolivas, LKML, Kostya Serebryany, syzkaller,
Dmitry Vyukov, Stephen Barber, Bhumika Goyal
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 */
--
2.14.2
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2017-10-10 12:19 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2017-10-09 17:50 usb/sound: use-after-free in snd_usb_mixer_interrupt Andrey Konovalov
2017-10-09 22:10 ` Takashi Iwai
2017-10-09 22:10 ` Takashi Iwai
2017-10-10 11:20 ` Andrey Konovalov
2017-10-10 12:19 ` Takashi Iwai
2017-10-10 12:19 ` Takashi Iwai
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