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MIME-Version: 1.0
Date:   Fri, 07 Jun 2019 14:53:05 -0700
Message-ID: <000000000000f8c953058ac2dae4@google.com>
Subject: KMSAN: uninit-value in read_sensor_register
From:   syzbot <syzbot+06ddf1788cfd048c5e82@syzkaller.appspotmail.com>
To:     glider@google.com, hverkuil@xs4all.nl,
        linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
        mchehab@kernel.org, syzkaller-bugs@googlegroups.com
Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes
Sender: linux-kernel-owner@vger.kernel.org
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Hello,

syzbot found the following crash on:

HEAD commit:    f75e4cfe kmsan: use kmsan_handle_urb() in urb.c
git tree:       kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=1454b01ea00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=602468164ccdc30a
dashboard link: https://syzkaller.appspot.com/bug?extid=06ddf1788cfd048c5e82
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
06d00afa61eef8f7f501ebdb4e8612ea43ec2d78)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=12cbead2a00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1683b761a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+06ddf1788cfd048c5e82@syzkaller.appspotmail.com

usb 1-1: config 0 has an invalid interface number: 110 but max is 0
usb 1-1: config 0 has no interface number 0
usb 1-1: New USB device found, idVendor=0ac8, idProduct=c301, bcdDevice=  
1.4a
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
gspca_main: vc032x-2.14.0 probing 0ac8:c301
gspca_vc032x: reg_w err -71
==================================================================
BUG: KMSAN: uninit-value in read_sensor_register+0x732/0x26a0  
drivers/media/usb/gspca/vc032x.c:2975
CPU: 1 PID: 33 Comm: kworker/1:1 Not tainted 5.1.0+ #1
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+0x130/0x2a0 mm/kmsan/kmsan.c:622
  __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
  read_sensor_register+0x732/0x26a0 drivers/media/usb/gspca/vc032x.c:2975
  vc032x_probe_sensor drivers/media/usb/gspca/vc032x.c:3036 [inline]
  sd_init+0x2f94/0x5330 drivers/media/usb/gspca/vc032x.c:3167
  gspca_dev_probe2+0xee0/0x2240 drivers/media/usb/gspca/gspca.c:1546
  gspca_dev_probe+0x346/0x3b0 drivers/media/usb/gspca/gspca.c:1619
  sd_probe+0x8d/0xa0 drivers/media/usb/gspca/gl860/gl860.c:523
  usb_probe_interface+0xd66/0x1320 drivers/usb/core/driver.c:361
  really_probe+0xdae/0x1d80 drivers/base/dd.c:513
  driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x454/0x730 drivers/base/dd.c:844
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
  bus_probe_device+0x137/0x390 drivers/base/bus.c:514
  device_add+0x288d/0x30e0 drivers/base/core.c:2106
  usb_set_configuration+0x30dc/0x3750 drivers/usb/core/message.c:2027
  generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
  usb_probe_device+0x14c/0x200 drivers/usb/core/driver.c:266
  really_probe+0xdae/0x1d80 drivers/base/dd.c:513
  driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x454/0x730 drivers/base/dd.c:844
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
  bus_probe_device+0x137/0x390 drivers/base/bus.c:514
  device_add+0x288d/0x30e0 drivers/base/core.c:2106
  usb_new_device+0x23e5/0x2ff0 drivers/usb/core/hub.c:2534
  hub_port_connect drivers/usb/core/hub.c:5089 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0x48d1/0x7290 drivers/usb/core/hub.c:5432
  process_one_work+0x1572/0x1f00 kernel/workqueue.c:2269
  worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
  kthread+0x4b5/0x4f0 kernel/kthread.c:254
  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:208 [inline]
  kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:162
  kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:175
  kmem_cache_alloc_trace+0x503/0xae0 mm/slub.c:2801
  kmalloc include/linux/slab.h:547 [inline]
  gspca_dev_probe2+0x30c/0x2240 drivers/media/usb/gspca/gspca.c:1480
  gspca_dev_probe+0x346/0x3b0 drivers/media/usb/gspca/gspca.c:1619
  sd_probe+0x8d/0xa0 drivers/media/usb/gspca/gl860/gl860.c:523
  usb_probe_interface+0xd66/0x1320 drivers/usb/core/driver.c:361
  really_probe+0xdae/0x1d80 drivers/base/dd.c:513
  driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x454/0x730 drivers/base/dd.c:844
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
  bus_probe_device+0x137/0x390 drivers/base/bus.c:514
  device_add+0x288d/0x30e0 drivers/base/core.c:2106
  usb_set_configuration+0x30dc/0x3750 drivers/usb/core/message.c:2027
  generic_probe+0xe7/0x280 drivers/usb/core/generic.c:210
  usb_probe_device+0x14c/0x200 drivers/usb/core/driver.c:266
  really_probe+0xdae/0x1d80 drivers/base/dd.c:513
  driver_probe_device+0x1b3/0x4f0 drivers/base/dd.c:671
  __device_attach_driver+0x5b8/0x790 drivers/base/dd.c:778
  bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
  __device_attach+0x454/0x730 drivers/base/dd.c:844
  device_initial_probe+0x4a/0x60 drivers/base/dd.c:891
  bus_probe_device+0x137/0x390 drivers/base/bus.c:514
  device_add+0x288d/0x30e0 drivers/base/core.c:2106
  usb_new_device+0x23e5/0x2ff0 drivers/usb/core/hub.c:2534
  hub_port_connect drivers/usb/core/hub.c:5089 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0x48d1/0x7290 drivers/usb/core/hub.c:5432
  process_one_work+0x1572/0x1f00 kernel/workqueue.c:2269
  worker_thread+0x111b/0x2460 kernel/workqueue.c:2415
  kthread+0x4b5/0x4f0 kernel/kthread.c:254
  ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
==================================================================


---
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