Hello, syzbot found the following crash on: HEAD commit: e17994d1 usb: core: kcov: collect coverage from usb comple.. git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=12d170ade00000 kernel config: https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60 dashboard link: https://syzkaller.appspot.com/bug?extid=df767d588771697b0433 compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14ac8b91e00000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1010e223e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+df767d588771697b0433@xxxxxxxxxxxxxxxxxxxxxxxxx pl2303 1-1:31.37: required endpoints missing hwa-hc 1-1:31.37: Wire Adapter v219.213 newer than groked v1.0 hwa-hc 1-1:31.37: FIXME: USB_MAXCHILDREN too low for WUSB adapter (62 ports) ------------[ cut here ]------------ WARNING: CPU: 0 PID: 95 at lib/vsprintf.c:2512 vsnprintf+0xf46/0x14f0 lib/vsprintf.c:2512 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 95 Comm: kworker/0:2 Not tainted 5.6.0-rc5-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 panic+0x2aa/0x6e1 kernel/panic.c:221 __warn.cold+0x2f/0x30 kernel/panic.c:582 report_bug+0x27b/0x2f0 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:267 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:vsnprintf+0xf46/0x14f0 lib/vsprintf.c:2512 Code: 10 83 c5 08 41 89 2f e8 f8 34 b3 fb 4c 89 f0 48 c1 e8 03 80 3c 18 00 0f 85 38 04 00 00 4d 8b 36 e9 bb f2 ff ff e8 da 34 b3 fb <0f> 0b 45 31 ed e9 71 f3 ff ff e8 cb 34 b3 fb 4c 89 e8 4c 89 ea 48 RSP: 0018:ffff8881d58c6fc8 EFLAGS: 00010293 RAX: ffff8881d7976200 RBX: fffffffffffffff7 RCX: ffffffff858c1258 RDX: 0000000000000000 RSI: ffffffff858c2106 RDI: 0000000000000007 RBP: ffffffff86881480 R08: ffff8881d7976200 R09: ffffed103ab18e4e R10: ffffed103ab18e4d R11: ffff8881d58c7269 R12: ffff8881d58c7279 R13: fffffffffffffff7 R14: ffffffff86881480 R15: ffff8881d58c70c8 snprintf+0xbb/0xf0 lib/vsprintf.c:2707 hwahc_security_create drivers/staging/wusbcore/host/hwa-hc.c:683 [inline] hwahc_create drivers/staging/wusbcore/host/hwa-hc.c:738 [inline] hwahc_probe+0xfd6/0x1490 drivers/staging/wusbcore/host/hwa-hc.c:805 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:2500 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:2500 usb_new_device.cold+0x540/0xcd0 drivers/usb/core/hub.c:2548 hub_port_connect drivers/usb/core/hub.c:5195 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x21cb/0x4300 drivers/usb/core/hub.c:5563 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 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches