Re: KMSAN: uninit-value in dvb_usb_adapter_dvb_init (2)

syzbot
2020-12-05T10:16:20Z

syzbot has found a reproducer for 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=170babf7500000
kernel config: https://syzkaller.appspot.com/x/.config?x=eef728deea880383
dashboard link: https://syzkaller.appspot.com/bug?extid=e27b4fd589762b0b9329
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=158833f7500000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=102a3437500000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e27b4fd589762b0b9329@syzkaller.appspotmail.com

dvb-usb: bulk message failed: -22 (5/0)
dvb-usb: bulk message failed: -22 (5/0)
dvb-usb: bulk message failed: -22 (5/0)
=====================================================
BUG: KMSAN: uninit-value in mac_address_string+0x1040/0x1170 lib/vsprintf.c:1281
CPU: 1 PID: 3485 Comm: kworker/1:2 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
__msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
mac_address_string+0x1040/0x1170 lib/vsprintf.c:1281
pointer+0x9fe/0x1ca0 lib/vsprintf.c:2241
vsnprintf+0x1a4f/0x3610 lib/vsprintf.c:2622
vscnprintf+0xbe/0x1c0 lib/vsprintf.c:2721
vprintk_store+0xff/0x14a0 kernel/printk/printk.c:1954
vprintk_emit+0x2ae/0x820 kernel/printk/printk.c:2018
vprintk_default+0x86/0xa0 kernel/printk/printk.c:2052
vprintk_func+0x2ed/0x2f0 kernel/printk/printk_safe.c:393
printk+0x180/0x1cd kernel/printk/printk.c:2083
dvb_usb_adapter_dvb_init+0x818/0x1300 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:166
dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:83 [inline]
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:173 [inline]
dvb_usb_device_init+0x27fd/0x3350 drivers/media/usb/dvb-usb/dvb-usb-init.c:287
nova_t_probe+0x73/0x80 drivers/media/usb/dvb-usb/nova-t-usb2.c:156
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
nova_t_read_mac_address+0x2d4/0x2f0 drivers/media/usb/dvb-usb/nova-t-usb2.c:144
dvb_usb_adapter_dvb_init+0x774/0x1300 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:165
dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:83 [inline]
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:173 [inline]
dvb_usb_device_init+0x27fd/0x3350 drivers/media/usb/dvb-usb/dvb-usb-init.c:287
nova_t_probe+0x73/0x80 drivers/media/usb/dvb-usb/nova-t-usb2.c:156
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
dibusb_read_eeprom_byte+0x513/0x540 drivers/media/usb/dvb-usb/dibusb-common.c:233
nova_t_read_mac_address+0x1e3/0x2f0 drivers/media/usb/dvb-usb/nova-t-usb2.c:142
dvb_usb_adapter_dvb_init+0x774/0x1300 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:165
dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:83 [inline]
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:173 [inline]
dvb_usb_device_init+0x27fd/0x3350 drivers/media/usb/dvb-usb/dvb-usb-init.c:287
nova_t_probe+0x73/0x80 drivers/media/usb/dvb-usb/nova-t-usb2.c:156
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 created at:
kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76
slab_alloc_node mm/slub.c:2906 [inline]
slab_alloc mm/slub.c:2915 [inline]
kmem_cache_alloc_trace+0x869/0x1020 mm/slub.c:2932
kmalloc include/linux/slab.h:552 [inline]
dibusb_read_eeprom_byte+0xad/0x540 drivers/media/usb/dvb-usb/dibusb-common.c:226
nova_t_read_mac_address+0x1e3/0x2f0 drivers/media/usb/dvb-usb/nova-t-usb2.c:142
dvb_usb_adapter_dvb_init+0x774/0x1300 drivers/media/usb/dvb-usb/dvb-usb-dvb.c:165
dvb_usb_adapter_init drivers/media/usb/dvb-usb/dvb-usb-init.c:83 [inline]
dvb_usb_init drivers/media/usb/dvb-usb/dvb-usb-init.c:173 [inline]
dvb_usb_device_init+0x27fd/0x3350 drivers/media/usb/dvb-usb/dvb-usb-init.c:287
nova_t_probe+0x73/0x80 drivers/media/usb/dvb-usb/nova-t-usb2.c:156
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
=====================================================