KMSAN: kernel-usb-infoleak in usbnet_write_cmd

From: syzbot
Date: Thu Aug 01 2019 - 11:28:19 EST


Hello,

syzbot found the following crash on:

HEAD commit: 41550654 [UPSTREAM] KVM: x86: degrade WARN to pr_warn_rate..
git tree: kmsan
console output: https://syzkaller.appspot.com/x/log.txt?x=13a0b07da00000
kernel config: https://syzkaller.appspot.com/x/.config?x=40511ad0c5945201
dashboard link: https://syzkaller.appspot.com/bug?extid=b33fff3d3de984c82064
compiler: clang version 9.0.0 (/home/glider/llvm/clang 80fee25776c2fb61e74c1ecb1a523375c2500b69)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+b33fff3d3de984c82064@xxxxxxxxxxxxxxxxxxxxxxxxx

ax88179_178a 3-1:0.239 (unnamed net_device) (uninitialized): Failed to write reg index 0x001f: -71
ax88179_178a 3-1:0.239 (unnamed net_device) (uninitialized): Failed to write reg index 0x001e: -71
ax88179_178a 3-1:0.239 (unnamed net_device) (uninitialized): Failed to read reg index 0x001a: -71
ax88179_178a 3-1:0.239 (unnamed net_device) (uninitialized): Failed to read reg index 0x001c: -71
==================================================================
BUG: KMSAN: kernel-usb-infoleak in usb_submit_urb+0x7ef/0x1f50 drivers/usb/core/urb.c:405
CPU: 0 PID: 12 Comm: kworker/0:1 Not tainted 5.2.0-rc4+ #7
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+0x162/0x2d0 mm/kmsan/kmsan.c:611
kmsan_internal_check_memory+0x974/0xa80 mm/kmsan/kmsan.c:705
kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:617
usb_submit_urb+0x7ef/0x1f50 drivers/usb/core/urb.c:405
usb_start_wait_urb+0x143/0x410 drivers/usb/core/message.c:58
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x49f/0x7f0 drivers/usb/core/message.c:156
__usbnet_write_cmd drivers/net/usb/usbnet.c:2020 [inline]
usbnet_write_cmd+0x386/0x430 drivers/net/usb/usbnet.c:2058
__ax88179_write_cmd drivers/net/usb/ax88179_178a.c:223 [inline]
ax88179_write_cmd drivers/net/usb/ax88179_178a.c:323 [inline]
ax88179_led_setting+0x1c76/0x2be0 drivers/net/usb/ax88179_178a.c:1184
ax88179_bind+0xe01/0x1a10 drivers/net/usb/ax88179_178a.c:1305
usbnet_probe+0x10d3/0x3950 drivers/net/usb/usbnet.c:1722
usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
really_probe+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890
bus_probe_device+0x131/0x390 drivers/base/bus.c:514
device_add+0x25b5/0x2df0 drivers/base/core.c:2111
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+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890
bus_probe_device+0x131/0x390 drivers/base/bus.c:514
device_add+0x25b5/0x2df0 drivers/base/core.c:2111
usb_new_device+0x23e5/0x2fb0 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+0x5853/0x7320 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: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:201 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:213 [inline]
kmsan_internal_chain_origin+0xcc/0x150 mm/kmsan/kmsan.c:414
kmsan_memcpy_memmove_metadata+0x9f9/0xe00 mm/kmsan/kmsan.c:297
kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:317
__msan_memcpy+0x56/0x70 mm/kmsan/kmsan_instr.c:139
kmemdup+0x107/0x140 mm/util.c:121
__usbnet_write_cmd drivers/net/usb/usbnet.c:2009 [inline]
usbnet_write_cmd+0x168/0x430 drivers/net/usb/usbnet.c:2058
__ax88179_write_cmd drivers/net/usb/ax88179_178a.c:223 [inline]
ax88179_write_cmd drivers/net/usb/ax88179_178a.c:323 [inline]
ax88179_led_setting+0x1c76/0x2be0 drivers/net/usb/ax88179_178a.c:1184
ax88179_bind+0xe01/0x1a10 drivers/net/usb/ax88179_178a.c:1305
usbnet_probe+0x10d3/0x3950 drivers/net/usb/usbnet.c:1722
usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
really_probe+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890
bus_probe_device+0x131/0x390 drivers/base/bus.c:514
device_add+0x25b5/0x2df0 drivers/base/core.c:2111
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+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890
bus_probe_device+0x131/0x390 drivers/base/bus.c:514
device_add+0x25b5/0x2df0 drivers/base/core.c:2111
usb_new_device+0x23e5/0x2fb0 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+0x5853/0x7320 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: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:201 [inline]
kmsan_save_stack mm/kmsan/kmsan.c:213 [inline]
kmsan_internal_chain_origin+0xcc/0x150 mm/kmsan/kmsan.c:414
__msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:200
ax88179_write_cmd drivers/net/usb/ax88179_178a.c:321 [inline]
ax88179_led_setting+0x20d3/0x2be0 drivers/net/usb/ax88179_178a.c:1184
ax88179_bind+0xe01/0x1a10 drivers/net/usb/ax88179_178a.c:1305
usbnet_probe+0x10d3/0x3950 drivers/net/usb/usbnet.c:1722
usb_probe_interface+0xd19/0x1310 drivers/usb/core/driver.c:361
really_probe+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890
bus_probe_device+0x131/0x390 drivers/base/bus.c:514
device_add+0x25b5/0x2df0 drivers/base/core.c:2111
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+0x1344/0x1d90 drivers/base/dd.c:513
driver_probe_device+0x1ba/0x510 drivers/base/dd.c:670
__device_attach_driver+0x5b8/0x790 drivers/base/dd.c:777
bus_for_each_drv+0x28e/0x3b0 drivers/base/bus.c:454
__device_attach+0x489/0x750 drivers/base/dd.c:843
device_initial_probe+0x4a/0x60 drivers/base/dd.c:890
bus_probe_device+0x131/0x390 drivers/base/bus.c:514
device_add+0x25b5/0x2df0 drivers/base/core.c:2111
usb_new_device+0x23e5/0x2fb0 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+0x5853/0x7320 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:256
ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355

Local variable description: ----buf.i129@ax88179_led_setting
Variable was created at:
__ax88179_read_cmd drivers/net/usb/ax88179_178a.c:226 [inline]
ax88179_read_cmd drivers/net/usb/ax88179_178a.c:299 [inline]
ax88179_led_setting+0x18ef/0x2be0 drivers/net/usb/ax88179_178a.c:1138
ax88179_bind+0xe01/0x1a10 drivers/net/usb/ax88179_178a.c:1305

Bytes 0-1 of 2 are uninitialized
Memory access of size 2 starts at ffff888039cbbad0
==================================================================


---
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