KMSAN: kernel-usb-infoleak in pcan_usb_wait_rsp

From: syzbot
Date: Wed Oct 16 2019 - 21:42:27 EST


Hello,

syzbot found the following crash on:

HEAD commit: c2453450 kmsan: kcov: prettify the code unpoisoning area->..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=11934730e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=3684f3c73f43899a
dashboard link: https://syzkaller.appspot.com/bug?extid=863724e7128e14b26732
compiler: clang version 9.0.0 (/home/glider/llvm/clang 80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12431287600000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1743306b600000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+863724e7128e14b26732@xxxxxxxxxxxxxxxxxxxxxxxxx

usb 1-1: config 0 interface 210 altsetting 0 endpoint 0x1 has an invalid bInterval 0, changing to 7
usb 1-1: New USB device found, idVendor=0c72, idProduct=000c, bcdDevice=7c.aa
usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0
usb 1-1: config 0 descriptor??
hub 1-1:0.210: ignoring external hub
=====================================================
BUG: KMSAN: kernel-usb-infoleak in kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:381
CPU: 0 PID: 2900 Comm: kworker/0:2 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:109
kmsan_internal_check_memory+0x3bb/0x4e0 mm/kmsan/kmsan.c:469
kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:381
usb_submit_urb+0x7ef/0x1f50 drivers/usb/core/urb.c:405
usb_start_wait_urb+0x143/0x410 drivers/usb/core/message.c:58
usb_bulk_msg+0x811/0x920 drivers/usb/core/message.c:257
pcan_usb_send_cmd drivers/net/can/usb/peak_usb/pcan_usb.c:127 [inline]
pcan_usb_wait_rsp+0x25c/0x6e0 drivers/net/can/usb/peak_usb/pcan_usb.c:151
pcan_usb_get_serial drivers/net/can/usb/peak_usb/pcan_usb.c:310 [inline]
pcan_usb_init+0xcc/0x450 drivers/net/can/usb/peak_usb/pcan_usb.c:801
peak_usb_create_dev drivers/net/can/usb/peak_usb/pcan_usb_core.c:809 [inline]
peak_usb_probe+0x1416/0x1b20 drivers/net/can/usb/peak_usb/pcan_usb_core.c:907
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:150 [inline]
kmsan_internal_poison_shadow+0x60/0x110 mm/kmsan/kmsan.c:133
kmsan_slab_alloc+0xaa/0x130 mm/kmsan/kmsan_hooks.c:101
slab_alloc_node mm/slub.c:2792 [inline]
slab_alloc mm/slub.c:2801 [inline]
kmem_cache_alloc_trace+0x8c5/0xd20 mm/slub.c:2818
kmalloc include/linux/slab.h:556 [inline]
peak_usb_create_dev drivers/net/can/usb/peak_usb/pcan_usb_core.c:753 [inline]
peak_usb_probe+0x544/0x1b20 drivers/net/can/usb/peak_usb/pcan_usb_core.c:907
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

Bytes 2-15 of 16 are uninitialized
Memory access of size 16 starts at ffff88810fa82fa0
=====================================================


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