KMSAN: kernel-usb-infoleak in usbnet_write_cmd (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 73d62e81 kmsan: random: prevent boot-time reports in _mix_..
git tree: https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=13ff7703500000
kernel config: https://syzkaller.appspot.com/x/.config?x=eef728deea880383
dashboard link: https://syzkaller.appspot.com/bug?extid=11567dab5754ad6ee82a
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)

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

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+11567d...@syzkaller.appspotmail.com

smsc75xx 5-1:1.0 (unnamed net_device) (uninitialized): Error reading E2P_CMD
=====================================================
BUG: KMSAN: kernel-usb-infoleak in kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:303
CPU: 1 PID: 17 Comm: kworker/1:0 Not tainted 5.10.0-rc4-syzkaller #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+0x21c/0x280 lib/dump_stack.c:118
kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
kmsan_internal_check_memory+0x484/0x520 mm/kmsan/kmsan.c:437
kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:303
usb_submit_urb+0x87f/0x2530 drivers/usb/core/urb.c:421
usb_start_wait_urb+0x155/0x4c0 drivers/usb/core/message.c:58
usb_internal_control_msg drivers/usb/core/message.c:102 [inline]
usb_control_msg+0x495/0x7d0 drivers/usb/core/message.c:153
__usbnet_write_cmd drivers/net/usb/usbnet.c:2010 [inline]
usbnet_write_cmd+0x3d3/0x480 drivers/net/usb/usbnet.c:2048
__smsc75xx_write_reg drivers/net/usb/smsc75xx.c:122 [inline]
smsc75xx_write_reg drivers/net/usb/smsc75xx.c:153 [inline]
smsc75xx_reset+0x389/0x8030 drivers/net/usb/smsc75xx.c:1065
smsc75xx_bind+0xf5a/0x13f0 drivers/net/usb/smsc75xx.c:1492
usbnet_probe+0x1169/0x3e90 drivers/net/usb/usbnet.c:1712
usb_probe_interface+0xfcc/0x1520 drivers/usb/core/driver.c:396
really_probe+0xebd/0x2420 drivers/base/dd.c:558
driver_probe_device+0x293/0x390 drivers/base/dd.c:738
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x538/0x860 drivers/base/dd.c:912
device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x399e/0x3f20 drivers/base/core.c:2936
usb_set_configuration+0x39cf/0x4010 drivers/usb/core/message.c:2159
usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:238
usb_probe_device+0x317/0x570 drivers/usb/core/driver.c:293
really_probe+0xebd/0x2420 drivers/base/dd.c:558
driver_probe_device+0x293/0x390 drivers/base/dd.c:738
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x538/0x860 drivers/base/dd.c:912
device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x399e/0x3f20 drivers/base/core.c:2936
usb_new_device+0x1bd6/0x2a30 drivers/usb/core/hub.c:2554
hub_port_connect drivers/usb/core/hub.c:5222 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5362 [inline]
port_event drivers/usb/core/hub.c:5508 [inline]
hub_event+0x5bc9/0x8890 drivers/usb/core/hub.c:5590
process_one_work+0x121c/0x1fc0 kernel/workqueue.c:2272
worker_thread+0x10cc/0x2740 kernel/workqueue.c:2418
kthread+0x51c/0x560 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226
kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246
__msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110
kmemdup+0x107/0x140 mm/util.c:130
__usbnet_write_cmd drivers/net/usb/usbnet.c:1999 [inline]
usbnet_write_cmd+0x1a0/0x480 drivers/net/usb/usbnet.c:2048
__smsc75xx_write_reg drivers/net/usb/smsc75xx.c:122 [inline]
smsc75xx_write_reg drivers/net/usb/smsc75xx.c:153 [inline]
smsc75xx_reset+0x389/0x8030 drivers/net/usb/smsc75xx.c:1065
smsc75xx_bind+0xf5a/0x13f0 drivers/net/usb/smsc75xx.c:1492
usbnet_probe+0x1169/0x3e90 drivers/net/usb/usbnet.c:1712
usb_probe_interface+0xfcc/0x1520 drivers/usb/core/driver.c:396
really_probe+0xebd/0x2420 drivers/base/dd.c:558
driver_probe_device+0x293/0x390 drivers/base/dd.c:738
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x538/0x860 drivers/base/dd.c:912
device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x399e/0x3f20 drivers/base/core.c:2936
usb_set_configuration+0x39cf/0x4010 drivers/usb/core/message.c:2159
usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:238
usb_probe_device+0x317/0x570 drivers/usb/core/driver.c:293
really_probe+0xebd/0x2420 drivers/base/dd.c:558
driver_probe_device+0x293/0x390 drivers/base/dd.c:738
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x538/0x860 drivers/base/dd.c:912
device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x399e/0x3f20 drivers/base/core.c:2936
usb_new_device+0x1bd6/0x2a30 drivers/usb/core/hub.c:2554
hub_port_connect drivers/usb/core/hub.c:5222 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5362 [inline]
port_event drivers/usb/core/hub.c:5508 [inline]
hub_event+0x5bc9/0x8890 drivers/usb/core/hub.c:5590
process_one_work+0x121c/0x1fc0 kernel/workqueue.c:2272
worker_thread+0x10cc/0x2740 kernel/workqueue.c:2418
kthread+0x51c/0x560 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Uninit was stored to memory at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
__msan_chain_origin+0x57/0xa0 mm/kmsan/kmsan_instr.c:147
__smsc75xx_write_reg drivers/net/usb/smsc75xx.c:119 [inline]
smsc75xx_write_reg drivers/net/usb/smsc75xx.c:153 [inline]
smsc75xx_reset+0x18fa/0x8030 drivers/net/usb/smsc75xx.c:1065
smsc75xx_bind+0xf5a/0x13f0 drivers/net/usb/smsc75xx.c:1492
usbnet_probe+0x1169/0x3e90 drivers/net/usb/usbnet.c:1712
usb_probe_interface+0xfcc/0x1520 drivers/usb/core/driver.c:396
really_probe+0xebd/0x2420 drivers/base/dd.c:558
driver_probe_device+0x293/0x390 drivers/base/dd.c:738
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x538/0x860 drivers/base/dd.c:912
device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x399e/0x3f20 drivers/base/core.c:2936
usb_set_configuration+0x39cf/0x4010 drivers/usb/core/message.c:2159
usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:238
usb_probe_device+0x317/0x570 drivers/usb/core/driver.c:293
really_probe+0xebd/0x2420 drivers/base/dd.c:558
driver_probe_device+0x293/0x390 drivers/base/dd.c:738
__device_attach_driver+0x63f/0x830 drivers/base/dd.c:844
bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431
__device_attach+0x538/0x860 drivers/base/dd.c:912
device_initial_probe+0x4a/0x60 drivers/base/dd.c:959
bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491
device_add+0x399e/0x3f20 drivers/base/core.c:2936
usb_new_device+0x1bd6/0x2a30 drivers/usb/core/hub.c:2554
hub_port_connect drivers/usb/core/hub.c:5222 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5362 [inline]
port_event drivers/usb/core/hub.c:5508 [inline]
hub_event+0x5bc9/0x8890 drivers/usb/core/hub.c:5590
process_one_work+0x121c/0x1fc0 kernel/workqueue.c:2272
worker_thread+0x10cc/0x2740 kernel/workqueue.c:2418
kthread+0x51c/0x560 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Local variable ----buf.i.i@smsc75xx_reset created at:
__smsc75xx_read_reg drivers/net/usb/smsc75xx.c:976 [inline]
smsc75xx_read_reg drivers/net/usb/smsc75xx.c:147 [inline]
smsc75xx_reset+0x23a/0x8030 drivers/net/usb/smsc75xx.c:1057
__smsc75xx_read_reg drivers/net/usb/smsc75xx.c:976 [inline]
smsc75xx_read_reg drivers/net/usb/smsc75xx.c:147 [inline]
smsc75xx_reset+0x23a/0x8030 drivers/net/usb/smsc75xx.c:1057

Bytes 0-3 of 4 are uninitialized
Memory access of size 4 starts at ffff8880a7403e28
=====================================================


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.