syzbot

usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
usb 1-1: config 0 descriptor??
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BUG: KASAN: slab-out-of-bounds in hex_string+0x439/0x4c0 lib/vsprintf.c:1137
Read of size 1 at addr ffff8881d4fa319b by task kworker/1:2/95

CPU: 1 PID: 95 Comm: kworker/1:2 Not tainted 5.6.0-rc3-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+0xef/0x16e lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x314 mm/kasan/report.c:374
 __kasan_report.cold+0x37/0x77 mm/kasan/report.c:506
 kasan_report+0xe/0x20 mm/kasan/common.c:641
 hex_string+0x439/0x4c0 lib/vsprintf.c:1137
 pointer+0x45b/0x680 lib/vsprintf.c:2193
 vsnprintf+0x5ac/0x14f0 lib/vsprintf.c:2578
 va_format.isra.0+0x129/0x1b0 lib/vsprintf.c:1652
 pointer+0x4bf/0x680 lib/vsprintf.c:2221
 vsnprintf+0x5ac/0x14f0 lib/vsprintf.c:2578
 vscnprintf+0x29/0x80 lib/vsprintf.c:2677
 vprintk_store+0x40/0x4b0 kernel/printk/printk.c:1917
 vprintk_emit+0xc8/0x3d0 kernel/printk/printk.c:1978
 dev_vprintk_emit+0x4fc/0x541 drivers/base/core.c:3603
 dev_printk_emit+0xba/0xf1 drivers/base/core.c:3614
 __dev_printk+0x1db/0x203 drivers/base/core.c:3626
 _dev_info+0xd7/0x109 drivers/base/core.c:3672
 dlfb_parse_vendor_descriptor drivers/video/fbdev/udlfb.c:1589 [inline]
 dlfb_usb_probe.cold+0xfd9/0x1ba3 drivers/video/fbdev/udlfb.c:1672
 usb_probe_interface+0x310/0x800 drivers/usb/core/driver.c:374
 really_probe+0x290/0xac0 drivers/base/dd.c:551
 driver_probe_device+0x223/0x350 drivers/base/dd.c:724
 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431
 __device_attach+0x217/0x390 drivers/base/dd.c:897
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
 device_add+0x1459/0x1bf0 drivers/base/core.c:2487
 usb_set_configuration+0xe47/0x17d0 drivers/usb/core/message.c:2023
 usb_generic_driver_probe+0x9d/0xe0 drivers/usb/core/generic.c:241
 usb_probe_device+0xd9/0x230 drivers/usb/core/driver.c:272
 really_probe+0x290/0xac0 drivers/base/dd.c:551
 driver_probe_device+0x223/0x350 drivers/base/dd.c:724
 __device_attach_driver+0x1d1/0x290 drivers/base/dd.c:831
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:431
 __device_attach+0x217/0x390 drivers/base/dd.c:897
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:491
 device_add+0x1459/0x1bf0 drivers/base/core.c:2487
 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2544
 hub_port_connect drivers/usb/core/hub.c:5191 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5331 [inline]
 port_event drivers/usb/core/hub.c:5477 [inline]
 hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5559
 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264
 worker_thread+0x96/0xe20 kernel/workqueue.c:2410
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Allocated by task 95:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:515 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:488
 kmalloc include/linux/slab.h:560 [inline]
 usb_get_configuration+0x311/0x3a20 drivers/usb/core/config.c:919
 usb_enumerate_device drivers/usb/core/hub.c:2377 [inline]
 usb_new_device+0x2f9/0x450 drivers/usb/core/hub.c:2513
 hub_port_connect drivers/usb/core/hub.c:5191 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5331 [inline]
 port_event drivers/usb/core/hub.c:5477 [inline]
 hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5559
 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264
 worker_thread+0x96/0xe20 kernel/workqueue.c:2410
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 1:
 save_stack+0x1b/0x80 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:337 [inline]
 __kasan_slab_free+0x117/0x160 mm/kasan/common.c:476
 slab_free_hook mm/slub.c:1444 [inline]
 slab_free_freelist_hook mm/slub.c:1477 [inline]
 slab_free mm/slub.c:3024 [inline]
 kfree+0xd5/0x300 mm/slub.c:3976
 kobject_uevent_env+0x2a3/0x1470 lib/kobject_uevent.c:624
 driver_register+0x27f/0x330 drivers/base/driver.c:179
 i2c_register_driver+0xd8/0x1a0 drivers/i2c/i2c-core-base.c:1693
 do_one_initcall+0x10a/0x6b0 init/main.c:1146
 do_initcall_level init/main.c:1219 [inline]
 do_initcalls init/main.c:1235 [inline]
 do_basic_setup init/main.c:1255 [inline]
 kernel_init_freeable+0x4e6/0x593 init/main.c:1439
 kernel_init+0xd/0x1b9 init/main.c:1346
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881d4fa3180
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 27 bytes inside of
 32-byte region [ffff8881d4fa3180, ffff8881d4fa31a0)
The buggy address belongs to the page:
page:ffffea000753e8c0 refcount:1 mapcount:0 mapping:ffff8881da003400 index:0x0
flags: 0x200000000000200(slab)
raw: 0200000000000200 ffffea000754d240 0000001000000010 ffff8881da003400
raw: 0000000000000000 0000000080400040 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d4fa3080: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8881d4fa3100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8881d4fa3180: 00 00 00 03 fc fc fc fc fb fb fb fb fc fc fc fc
                            ^
 ffff8881d4fa3200: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8881d4fa3280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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