UBSAN: undefined-behaviour in est_timer

Status: upstream: reported C repro on 2020/09/21 13:24
Reported-by: syzbot+5cd4ec077063ccba1fff@syzkaller.appspotmail.com
First crash: 2164d, last: 2134d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
================================================================================
UBSAN: Undefined behaviour in net/core/gen_estimator.c:87:38
shift exponent -23 is negative
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.150-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:77 [inline]
 dump_stack+0x22c/0x33e lib/dump_stack.c:118
 ubsan_epilogue+0xe/0x3a lib/ubsan.c:161
 __ubsan_handle_shift_out_of_bounds.cold+0x1c4/0x250 lib/ubsan.c:422
 est_timer.cold+0x96/0x126 net/core/gen_estimator.c:87
 call_timer_fn+0x177/0x760 kernel/time/timer.c:1338
 expire_timers+0x243/0x500 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1703 [inline]
 run_timer_softirq+0x259/0x730 kernel/time/timer.c:1716
 __do_softirq+0x27d/0xad2 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x22d/0x270 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:544 [inline]
 smp_apic_timer_interrupt+0x15f/0x5d0 arch/x86/kernel/apic/apic.c:1094
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: e9 73 fd ff ff 48 89 df e8 2f 15 fa f9 e9 59 ff ff ff 90 90 90 90 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d f4 4a 57 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d e4 4a 57 00 f4 c3 90 90 41 56 41 55
RSP: 0018:ffff8880a9a6fd58 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff12c7140 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880a9a60c44
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff896389f0
R13: 1ffff1101534dfb5 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x49/0x320 arch/x86/kernel/process.c:557
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2f8/0x500 kernel/sched/idle.c:263
 cpu_startup_entry+0xc5/0xd6 kernel/sched/idle.c:369
 start_secondary+0x44d/0x610 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
================================================================================
================================================================================
UBSAN: Undefined behaviour in net/core/gen_estimator.c:90:46
shift exponent -23 is negative
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.19.150-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:77 [inline]
 dump_stack+0x22c/0x33e lib/dump_stack.c:118
 ubsan_epilogue+0xe/0x3a lib/ubsan.c:161
 __ubsan_handle_shift_out_of_bounds.cold+0x1c4/0x250 lib/ubsan.c:422
 est_timer.cold+0x17/0x126 net/core/gen_estimator.c:90
 call_timer_fn+0x177/0x760 kernel/time/timer.c:1338
 expire_timers+0x243/0x500 kernel/time/timer.c:1375
 __run_timers kernel/time/timer.c:1703 [inline]
 run_timer_softirq+0x259/0x730 kernel/time/timer.c:1716
 __do_softirq+0x27d/0xad2 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x22d/0x270 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:544 [inline]
 smp_apic_timer_interrupt+0x15f/0x5d0 arch/x86/kernel/apic/apic.c:1094
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:894
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: e9 73 fd ff ff 48 89 df e8 2f 15 fa f9 e9 59 ff ff ff 90 90 90 90 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d f4 4a 57 00 fb f4 <c3> 90 e9 07 00 00 00 0f 00 2d e4 4a 57 00 f4 c3 90 90 41 56 41 55
RSP: 0018:ffff8880a9a6fd58 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff12c7140 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff8880a9a60c44
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff896389f0
R13: 1ffff1101534dfb5 R14: 0000000000000000 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x49/0x320 arch/x86/kernel/process.c:557
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2f8/0x500 kernel/sched/idle.c:263
 cpu_startup_entry+0xc5/0xd6 kernel/sched/idle.c:369
 start_secondary+0x44d/0x610 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243
================================================================================

Crashes (60):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/10/15 13:28 linux-4.19.y a1b977b49b66 63869021 .config console log report syz C ci2-linux-4-19
2020/09/24 01:22 linux-4.19.y d09b80172c22 54289b08 .config console log report syz C ci2-linux-4-19
2020/10/21 21:40 linux-4.19.y ad326970d25c 99c64d5c .config console log report info ci2-linux-4-19
2020/10/20 19:24 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/20 18:15 linux-4.19.y ad326970d25c ff4a3345 .config console log report info ci2-linux-4-19
2020/10/19 05:35 linux-4.19.y ad326970d25c fea47c01 .config console log report info ci2-linux-4-19
2020/10/16 05:45 linux-4.19.y a1b977b49b66 6e262c73 .config console log report info ci2-linux-4-19
2020/10/13 06:28 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/13 02:31 linux-4.19.y a1b977b49b66 d32b0bbf .config console log report info ci2-linux-4-19
2020/10/11 02:11 linux-4.19.y a1b977b49b66 4a77ae0b .config console log report info ci2-linux-4-19
2020/10/08 20:18 linux-4.19.y a1b977b49b66 92390980 .config console log report info ci2-linux-4-19
2020/10/07 00:33 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 15:35 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 13:13 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 09:54 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/06 01:42 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 23:23 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 18:51 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 15:51 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 15:50 linux-4.19.y b09c34517e1a 1880b4a9 .config console log report info ci2-linux-4-19
2020/10/05 09:33 linux-4.19.y b09c34517e1a 5ef9c291 .config console log report info ci2-linux-4-19
2020/10/04 08:30 linux-4.19.y b09c34517e1a 1a3f9408 .config console log report info ci2-linux-4-19
2020/10/03 07:57 linux-4.19.y b09c34517e1a 2653fa43 .config console log report info ci2-linux-4-19
2020/10/03 01:02 linux-4.19.y b09c34517e1a 062c9832 .config console log report info ci2-linux-4-19
2020/10/01 07:45 linux-4.19.y 10ad6cfd5736 a9767fb2 .config console log report info ci2-linux-4-19
2020/10/01 06:17 linux-4.19.y 10ad6cfd5736 a9767fb2 .config console log report info ci2-linux-4-19
2020/10/01 05:31 linux-4.19.y 10ad6cfd5736 a9767fb2 .config console log report info ci2-linux-4-19
2020/10/01 02:55 linux-4.19.y 10ad6cfd5736 a9767fb2 .config console log report info ci2-linux-4-19
2020/09/30 21:17 linux-4.19.y 10ad6cfd5736 a9767fb2 .config console log report info ci2-linux-4-19
2020/09/30 10:33 linux-4.19.y 10ad6cfd5736 8516f6d3 .config console log report info ci2-linux-4-19
2020/09/30 03:33 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/30 03:27 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/30 02:45 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/30 02:37 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/29 19:57 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/29 19:38 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/29 19:10 linux-4.19.y 10ad6cfd5736 5abc3f1a .config console log report info ci2-linux-4-19
2020/09/29 09:25 linux-4.19.y 10ad6cfd5736 1b88c6d5 .config console log report info ci2-linux-4-19
2020/09/29 07:08 linux-4.19.y 10ad6cfd5736 1b88c6d5 .config console log report info ci2-linux-4-19
2020/09/28 21:38 linux-4.19.y 10ad6cfd5736 6bfdbe89 .config console log report info ci2-linux-4-19
2020/09/28 20:49 linux-4.19.y 10ad6cfd5736 6bfdbe89 .config console log report info ci2-linux-4-19
2020/09/28 20:42 linux-4.19.y 10ad6cfd5736 6bfdbe89 .config console log report info ci2-linux-4-19
2020/09/28 20:34 linux-4.19.y 10ad6cfd5736 6bfdbe89 .config console log report info ci2-linux-4-19
2020/09/28 15:40 linux-4.19.y 10ad6cfd5736 6bfdbe89 .config console log report info ci2-linux-4-19
2020/09/28 06:26 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/28 06:13 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/28 06:10 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/27 21:21 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/27 21:21 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/27 21:04 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/27 08:35 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/27 02:20 linux-4.19.y 10ad6cfd5736 5dd8aee8 .config console log report info ci2-linux-4-19
2020/09/26 14:46 linux-4.19.y d09b80172c22 2d5ea0cb .config console log report info ci2-linux-4-19
2020/09/26 04:03 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/25 19:25 linux-4.19.y d09b80172c22 4a006f63 .config console log report info ci2-linux-4-19
2020/09/23 23:27 linux-4.19.y d09b80172c22 54289b08 .config console log report info ci2-linux-4-19
2020/09/21 13:23 linux-4.19.y 015e94d0e37b c81d99c8 .config console log report info ci2-linux-4-19
* Struck through repros no longer work on HEAD.