syzbot


INFO: rcu detected stall in hrtimer_nanosleep_restart

Status: auto-obsoleted due to no activity on 2024/09/16 21:59
Reported-by: syzbot+fe10d1668fb1534e397e@syzkaller.appspotmail.com
First crash: 178d, last: 178d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=40397, q=41 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294978066-4294967564), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g40397 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26680 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5245 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6558
 schedule+0xbf/0x180 kernel/sched/core.c:6634
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 6568 Comm: syz-executor.2 Not tainted 6.1.92-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124
Code: 37 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 7b 20 36 09 e8 36 26 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28
RSP: 0018:ffffc90005b6f948 EFLAGS: 00000286
RAX: ae7d611cc4645400 RBX: ffff88802057d974 RCX: ffffffff91c94103
RDX: dffffc0000000000 RSI: ffffffff8aec01c0 RDI: ffff888020306f38
RBP: ffffc90005b6f990 R08: dffffc0000000000 R09: ffffed1017307541
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888020305940
R13: 1ffff110173076eb R14: ffff8880b983aa00 R15: ffff8880b983b758
FS:  00005555569fa480(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fbd0c38af00 CR3: 00000000214a5000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 context_switch kernel/sched/core.c:5248 [inline]
 __schedule+0x1435/0x4550 kernel/sched/core.c:6558
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
 irqentry_exit+0x53/0x80 kernel/entry/common.c:439
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:207 [inline]
RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:239 [inline]
RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline]
RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:118 [inline]
RIP: 0010:need_resched include/linux/sched.h:2231 [inline]
RIP: 0010:schedule+0xdb/0x180 kernel/sched/core.c:6636
Code: 00 00 e8 48 c9 ca f6 31 ff e8 f1 b9 ff ff bf 01 00 00 00 e8 b7 ca ca f6 4c 89 e7 be 08 00 00 00 e8 3a 85 4e f7 42 80 3c 3b 00 <74> c7 4c 89 e7 e8 9b 83 4e f7 eb bd 4d 89 e6 49 83 c6 2c 4c 89 f0
RSP: 0018:ffffc90005b6fcd8 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 1ffff11004060b28 RCX: ffffffff8a938926
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888020305940
RBP: ffffc90005b6fdf0 R08: dffffc0000000000 R09: ffffed1004060b29
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888020305940
R13: ffffc90005b6fe80 R14: ffff888020306bb8 R15: dffffc0000000000
 do_nanosleep+0x192/0x5f0 kernel/time/hrtimer.c:2045
 hrtimer_nanosleep_restart+0x2f4/0x420 kernel/time/hrtimer.c:2079
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fbd0b6a8375
Code: 24 0c 89 3c 24 48 89 4c 24 18 e8 f6 b9 ff ff 4c 8b 54 24 18 48 8b 54 24 10 41 89 c0 8b 74 24 0c 8b 3c 24 b8 e6 00 00 00 0f 05 <44> 89 c7 48 89 04 24 e8 4f ba ff ff 48 8b 04 24 48 83 c4 28 f7 d8
RSP: 002b:00007ffc844a9330 EFLAGS: 00000293 ORIG_RAX: 00000000000000db
RAX: ffffffffffffffda RBX: 00007fbd0b7b3f80 RCX: 00007fbd0b6a8375
RDX: 00007ffc844a9370 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fbd0b7b5980 R08: 0000000000000000 R09: 0000000000000010
R10: 0000000000000000 R11: 0000000000000293 R12: 000000000004acc2
R13: 00007fbd0b7b412c R14: 0000000000000032 R15: 00007fbd0b7b5980
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/08 21:59 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in hrtimer_nanosleep_restart
* Struck through repros no longer work on HEAD.