Hello, syzbot found the following issue on: HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing console output: https://syzkaller.appspot.com/x/log.txt?x=11b1a46b500000 kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 dashboard link: https://syzkaller.appspot.com/bug?extid=6d31bf169a8265204b8d compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13727b7f500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1565f123500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+6d31bf169a8265204b8d@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================================ UBSAN: shift-out-of-bounds in drivers/media/rc/mceusb.c:704:13 shift exponent 230 is too large for 32-bit type 'unsigned int' CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 ubsan_epilogue+0xb/0x5a lib/ubsan.c:148 __ubsan_handle_shift_out_of_bounds.cold+0xb1/0x181 lib/ubsan.c:395 mceusb_dev_printdata.cold+0x19/0x1e drivers/media/rc/mceusb.c:704 mceusb_process_ir_data drivers/media/rc/mceusb.c:1275 [inline] mceusb_dev_recv+0x3cb/0x1990 drivers/media/rc/mceusb.c:1376 __usb_hcd_giveback_urb+0x2b0/0x5c0 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x38c/0x430 drivers/usb/core/hcd.c:1728 dummy_timer+0x11f4/0x32a0 drivers/usb/gadget/udc/dummy_hcd.c:1971 call_timer_fn+0x1a5/0x690 kernel/time/timer.c:1417 expire_timers kernel/time/timer.c:1462 [inline] __run_timers.part.0+0x692/0xa50 kernel/time/timer.c:1731 __run_timers kernel/time/timer.c:1712 [inline] run_timer_softirq+0x80/0x120 kernel/time/timer.c:1744 __do_softirq+0x1b7/0x9c5 kernel/softirq.c:343 asm_call_irq_on_stack+0xf/0x20 </IRQ> __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x80/0xa0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:226 [inline] __irq_exit_rcu+0x119/0x1b0 kernel/softirq.c:420 irq_exit_rcu+0x5/0x10 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x43/0xa0 arch/x86/kernel/apic/apic.c:1096 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:79 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:169 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] RIP: 0010:acpi_idle_do_entry+0x1c9/0x250 drivers/acpi/processor_idle.c:516 Code: 8d 61 7f fb 84 db 75 ac e8 04 5b 7f fb e8 4f 0f 85 fb e9 0c 00 00 00 e8 f5 5a 7f fb 0f 00 2d ce 86 87 00 e8 e9 5a 7f fb fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 c4 62 7f fb 48 85 db RSP: 0018:ffffffff87407d60 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffffffff87431940 RSI: ffffffff85c0eb77 RDI: ffffffff85c0eb61 RBP: ffff8881037c3064 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff8145fae8 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8881037c3000 R14: ffff8881037c3064 R15: ffff888105c7d804 acpi_idle_enter+0x355/0x4f0 drivers/acpi/processor_idle.c:647 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351 call_cpuidle kernel/sched/idle.c:158 [inline] cpuidle_idle_call kernel/sched/idle.c:239 [inline] do_idle+0x3df/0x580 kernel/sched/idle.c:299 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:396 start_kernel+0x498/0x4b9 init/main.c:1061 secondary_startup_64_no_verify+0xb0/0xbb ================================================================================ --- This report 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 issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. syzbot can test patches for this issue, for details see: https://goo.gl/tpsmEJ#testing-patches