syzbot


KMSAN: use-after-free in build_audio_procunit

Status: fixed on 2019/11/29 15:48
Subsystems: usb sound
[Documentation on labels]
Fix commit: 976a68f06b2e ALSA: usb-audio: Fix incorrect size check for processing/extension units
First crash: 1634d, last: 1634d

Sample crash report:
=====================================================
BUG: KMSAN: use-after-free in build_audio_procunit+0x1be8/0x2490 sound/usb/mixer.c:2438
CPU: 1 PID: 31 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+0x14a/0x2f0 mm/kmsan/kmsan_report.c:110
 __msan_warning+0x73/0xf0 mm/kmsan/kmsan_instr.c:245
 build_audio_procunit+0x1be8/0x2490 sound/usb/mixer.c:2438
 parse_audio_unit+0x115c/0x7490 sound/usb/mixer.c:2483
 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+0x60/0x110 mm/kmsan/kmsan.c:134
 kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:108
 slab_free_freelist_hook mm/slub.c:1473 [inline]
 slab_free mm/slub.c:3040 [inline]
 kfree+0x4c1/0x2e70 mm/slub.c:3990
 urb_destroy drivers/usb/core/urb.c:27 [inline]
 kref_put include/linux/kref.h:65 [inline]
 usb_free_urb+0x12b/0x160 drivers/usb/core/urb.c:96
 usb_start_wait_urb+0x3a4/0x410 drivers/usb/core/message.c:80
 usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
 usb_control_msg+0x49f/0x7f0 drivers/usb/core/message.c:156
 usb_get_descriptor+0x19e/0x6c0 drivers/usb/core/message.c:651
 usb_get_configuration+0x6ea/0x76a0 drivers/usb/core/config.c:866
 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
=====================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/10/22 20:51 https://github.com/google/kmsan.git master 3c8ca70889aa 5681358a .config console log report syz C ci-upstream-kmsan-gce
2019/10/22 18:48 https://github.com/google/kmsan.git master 3c8ca70889aa 5681358a .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.