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UBSAN: shift-out-of-bounds in net/core/gen_estimator.c:83:38
shift exponent -2 is negative
CPU: 0 PID: 5712 Comm: kworker/u4:6 Not tainted 5.11.0-rc2-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
 est_timer.cold+0xbb/0x12d net/core/gen_estimator.c:83
 call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1417
 expire_timers kernel/time/timer.c:1462 [inline]
 __run_timers.part.0+0x67c/0xa50 kernel/time/timer.c:1731
 __run_timers kernel/time/timer.c:1712 [inline]
 run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1744
 __do_softirq+0x2bc/0xa29 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+0xaa/0xd0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:226 [inline]
 __irq_exit_rcu kernel/softirq.c:420 [inline]
 irq_exit_rcu+0x134/0x200 kernel/softirq.c:432
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1096
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:628
RIP: 0010:fpu__drop+0x0/0x4b0 arch/x86/kernel/fpu/core.c:322
Code: 02 84 c0 74 04 3c 03 7e 11 c7 03 ff ff ff ff 5b c3 e8 a4 88 49 00 0f 0b eb cd 48 89 df e8 f8 44 8c 00 eb e5 66 0f 1f 44 00 00 <55> 48 89 fd 53 e8 86 88 49 00 bf 01 00 00 00 e8 3c 51 24 00 65 48
RSP: 0018:ffffc9000334fde8 EFLAGS: 00000246
RAX: 0000000000004000 RBX: ffff888074850000 RCX: ffffffff8128dcb4
RDX: 1ffff1100e90a000 RSI: 0000000000000008 RDI: ffff888074851740
RBP: ffff888074850598 R08: 0000000000000000 R09: ffff888074850007
R10: ffffed100e90a000 R11: 0000000000000000 R12: ffff8880170bf500
R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000000
 do_exit+0xc64/0x2ae0 kernel/exit.c:826
 call_usermodehelper_exec_async+0x413/0x580 kernel/umh.c:123
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296
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