KMSAN: uninit-value in get_term_name

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: d86c1556 kmsan: add printk_test()
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=16c4ef54e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=c07a3d4f8a59e198
dashboard link: https://syzkaller.appspot.com/bug?extid=8f2612936028bfd28f28
compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11b96c4ce00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11a51ca8e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+8f2612...@syzkaller.appspotmail.com

usb 1-1: New USB device found, idVendor=1d6b, idProduct=0101, bcdDevice=
0.40
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
=====================================================
BUG: KMSAN: uninit-value in get_term_name+0x1b7/0xad0 sound/usb/mixer.c:652
CPU: 1 PID: 30 Comm: kworker/1:1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x191/0x1f0 lib/dump_stack.c:113
kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108
__msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:245
get_term_name+0x1b7/0xad0 sound/usb/mixer.c:652
__build_feature_ctl+0x11f1/0x29e0 sound/usb/mixer.c:1628
build_feature_ctl sound/usb/mixer.c:1709 [inline]
parse_audio_feature_unit sound/usb/mixer.c:1921 [inline]
parse_audio_unit+0x2308/0x7490 sound/usb/mixer.c:2753
snd_usb_mixer_controls sound/usb/mixer.c:3095 [inline]
snd_usb_create_mixer+0x1d7c/0x4070 sound/usb/mixer.c:3445
usb_audio_probe+0x286b/0x3eb0 sound/usb/card.c:653
usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
really_probe+0xd91/0x1f90 drivers/base/dd.c:552
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:721
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:828
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:430
__device_attach+0x489/0x750 drivers/base/dd.c:894
device_initial_probe+0x4a/0x60 drivers/base/dd.c:941
bus_probe_device+0x131/0x390 drivers/base/bus.c:490
device_add+0x25b5/0x2df0 drivers/base/core.c:2201
usb_set_configuration+0x309f/0x3710 drivers/usb/core/message.c:2027
generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
usb_probe_device+0x146/0x200 drivers/usb/core/driver.c:266
really_probe+0xd91/0x1f90 drivers/base/dd.c:552
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:721
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:828
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:430
__device_attach+0x489/0x750 drivers/base/dd.c:894
device_initial_probe+0x4a/0x60 drivers/base/dd.c:941
bus_probe_device+0x131/0x390 drivers/base/bus.c:490
device_add+0x25b5/0x2df0 drivers/base/core.c:2201
usb_new_device+0x23e5/0x2fb0 drivers/usb/core/hub.c:2536
hub_port_connect drivers/usb/core/hub.c:5098 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
port_event drivers/usb/core/hub.c:5359 [inline]
hub_event+0x581d/0x72f0 drivers/usb/core/hub.c:5441
process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269
worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
kthread+0x4b5/0x4f0 kernel/kthread.c:256
ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline]
kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:319
__msan_chain_origin+0x6b/0xd0 mm/kmsan/kmsan_instr.c:179
parse_term_proc_unit+0x73d/0x7e0 sound/usb/mixer.c:896
__check_input_term+0x13ef/0x2360 sound/usb/mixer.c:989
check_input_term sound/usb/mixer.c:1008 [inline]
parse_audio_feature_unit sound/usb/mixer.c:1875 [inline]
parse_audio_unit+0x1478/0x7490 sound/usb/mixer.c:2753
snd_usb_mixer_controls sound/usb/mixer.c:3095 [inline]
snd_usb_create_mixer+0x1d7c/0x4070 sound/usb/mixer.c:3445
usb_audio_probe+0x286b/0x3eb0 sound/usb/card.c:653
usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
really_probe+0xd91/0x1f90 drivers/base/dd.c:552
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:721
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:828
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:430
__device_attach+0x489/0x750 drivers/base/dd.c:894
device_initial_probe+0x4a/0x60 drivers/base/dd.c:941
bus_probe_device+0x131/0x390 drivers/base/bus.c:490
device_add+0x25b5/0x2df0 drivers/base/core.c:2201
usb_set_configuration+0x309f/0x3710 drivers/usb/core/message.c:2027
generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
usb_probe_device+0x146/0x200 drivers/usb/core/driver.c:266
really_probe+0xd91/0x1f90 drivers/base/dd.c:552
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:721
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:828
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:430
__device_attach+0x489/0x750 drivers/base/dd.c:894
device_initial_probe+0x4a/0x60 drivers/base/dd.c:941
bus_probe_device+0x131/0x390 drivers/base/bus.c:490
device_add+0x25b5/0x2df0 drivers/base/core.c:2201
usb_new_device+0x23e5/0x2fb0 drivers/usb/core/hub.c:2536
hub_port_connect drivers/usb/core/hub.c:5098 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
port_event drivers/usb/core/hub.c:5359 [inline]
hub_event+0x581d/0x72f0 drivers/usb/core/hub.c:5441
process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269
worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
kthread+0x4b5/0x4f0 kernel/kthread.c:256
ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Uninit was created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline]
kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:134
kmsan_slab_alloc+0xaa/0x120 mm/kmsan/kmsan_hooks.c:88
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2801 [inline]
__kmalloc+0x28e/0x430 mm/slub.c:3832
kmalloc include/linux/slab.h:561 [inline]
usb_get_configuration+0x50d/0x76a0 drivers/usb/core/config.c:857
usb_enumerate_device drivers/usb/core/hub.c:2369 [inline]
usb_new_device+0x224/0x2fb0 drivers/usb/core/hub.c:2505
hub_port_connect drivers/usb/core/hub.c:5098 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
port_event drivers/usb/core/hub.c:5359 [inline]
hub_event+0x581d/0x72f0 drivers/usb/core/hub.c:5441
process_one_work+0x1572/0x1ef0 kernel/workqueue.c:2269
worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
kthread+0x4b5/0x4f0 kernel/kthread.c:256
ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
=====================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches

[Takashi Iwai]

On Mon, 28 Oct 2019 11:32:07 +0100,
syzbot wrote:
>
> Uninit was stored to memory at:
> kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline]
> kmsan_internal_chain_origin+0xbd/0x180 mm/kmsan/kmsan.c:319
> __msan_chain_origin+0x6b/0xd0 mm/kmsan/kmsan_instr.c:179
> parse_term_proc_unit+0x73d/0x7e0 sound/usb/mixer.c:896
> __check_input_term+0x13ef/0x2360 sound/usb/mixer.c:989

So this comes from the invalid descriptor for a processing unit, and
it's very likely the same issue as already spotted -- the validator up
to 5.3-rc4 had a bug that passed the invalid descriptor falsely.
This should have been covered by 5.3-rc5, commit ba8bf0967a15 ("ALSA:
usb-audio: Fix copy&paste error in the validator").


thanks,

Takashi

[Alexander Potapenko]

Ah, thanks. Looks like I need to rebase the KMSAN tree.
>
> thanks,
>
> Takashi



--
Alexander Potapenko
Software Engineer

Google Germany GmbH
Erika-Mann-Straße, 33
80636 München

Geschäftsführer: Paul Manicle, Halimah DeLaine Prado
Registergericht und -nummer: Hamburg, HRB 86891
Sitz der Gesellschaft: Hamburg

[Greg KH]

SHould we be backporting the validator to any older kernels as well?

thanks,

greg k-h

[Andrey Konovalov]

On Mon, Oct 28, 2019 at 2:13 PM Takashi Iwai <ti...@suse.de> wrote:
>

#syz dup: KASAN: slab-out-of-bounds Read in build_audio_procunit

[Takashi Iwai]

Yes, that would be nice. I didn't mark them for stable just because
they are a bit largish and wanted to let them tested for 5.4 for a
while.

The following commits are relevant (from top/old to bottom/new).

57f8770620e9b51c61089751f0b5ad3dbe376ff2
ALSA: usb-audio: More validations of descriptor units
68e9fde245591d18200f8a9054cac22339437adb
ALSA: usb-audio: Simplify parse_audio_unit()
52c3e317a857091fd746e15179a637f32be4d337
ALSA: usb-audio: Unify the release of usb_mixer_elem_info objects
b8e4f1fdfa422398c2d6c47bfb7d1feb3046d70a
ALSA: usb-audio: Remove superfluous bLength checks
e0ccdef92653f8867e2d1667facfd3c23699f540
ALSA: usb-audio: Clean up check_input_term()
60849562a5db4a1eee2160167e4dce4590d3eafe
ALSA: usb-audio: Fix possible NULL dereference at create_yamaha_midi_quirk()
b39e077fcb283dd96dd251a3abeba585402c61fe
ALSA: usb-audio: remove some dead code
ba8bf0967a154796be15c4983603aad0b05c3138

ALSA: usb-audio: Fix copy&paste error in the validator

thanks,

Takashi

[Greg KH]

Thanks, I'll look at these for the next round of kernels.

greg k-h

[Greg KH]

Thanks, I've queued this series up for 5.3.y and 4.19.y

greg k-h