syzbot


INFO: rcu detected stall in preempt_schedule_thunk

Status: upstream: reported on 2024/05/17 23:34
Reported-by: syzbot+7736a03db8e990abb6bf@syzkaller.appspotmail.com
First crash: 38d, last: 38d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 0, t=10502 jiffies, g=7517, q=16 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10494 (4294957252-4294946758), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10494 jiffies! g7517 f0x2 RCU_GP_CLEANUP(7) ->state=0x0 ->cpu=1
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
 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:kasan_mem_to_shadow include/linux/kasan.h:59 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x33/0x290 mm/kasan/generic.c:189
Code: 85 f6 0f 84 9a 01 00 00 48 89 fd 48 01 f5 0f 82 5a 02 00 00 48 89 fd 48 c1 ed 2f 81 fd ff ff 01 00 0f 82 47 02 00 00 48 89 fb <48> c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4e 8d 0c 03 4c 8d 54 37
RSP: 0018:ffffc90000157b98 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff88813fee5940 RCX: ffffffff8a936c06
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88813fee5940
RBP: 000000000001ffff R08: dffffc0000000000 R09: ffffed1017327541
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200002af80
R13: ffffc90000067700 R14: ffffffff8a936b59 R15: dffffc0000000000
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 test_ti_thread_flag include/linux/thread_info.h:118 [inline]
 need_resched include/linux/sched.h:2231 [inline]
 preempt_schedule_common+0xa6/0xd0 kernel/sched/core.c:6735
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
 _raw_spin_unlock_irq+0x3c/0x40 kernel/locking/spinlock.c:202
 rcu_gp_cleanup+0x1ff/0xd80 kernel/rcu/tree.c:1788
 rcu_gp_kthread+0xb1/0x3b0 kernel/rcu/tree.c:1909
 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 3930 Comm: syz-executor.4 Not tainted 6.1.91-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024
RIP: 0010:debug_lockdep_rcu_enabled+0x28/0x30 kernel/rcu/update.c:280
Code: cc cc 31 c0 83 3d a7 9b e8 03 00 74 1d 83 3d 32 cf e8 03 00 74 14 65 48 8b 0d 44 81 77 75 31 c0 83 b9 dc 0a 00 00 00 0f 94 c0 <c3> cc cc cc cc cc cc cc 48 8b 3c 24 e8 57 fb ff ff 66 90 66 90 e9
RSP: 0018:ffffc900055a7c18 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff888075371dc0 RCX: ffff888075371dc0
RDX: 0000000000000000 RSI: ffffffff8aec1340 RDI: ffffffff8b3d4560
RBP: ffffc900055a7d40 R08: ffffffff81cdc9dc R09: ffffc900055a7e20
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000084 R15: 1ffff92000ab4f8c
FS:  00007f69186426c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32a33000 CR3: 000000001ea0b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <TASK>
 __might_resched+0xdb/0x780 kernel/sched/core.c:9904
 __might_fault+0x69/0x110 mm/memory.c:5832
 rseq_get_rseq_cs kernel/rseq.c:132 [inline]
 rseq_ip_fixup kernel/rseq.c:252 [inline]
 __rseq_handle_notify_resume+0x11e/0x1500 kernel/rseq.c:300
 rseq_handle_notify_resume include/linux/sched.h:2329 [inline]
 resume_user_mode_work include/linux/resume_user_mode.h:61 [inline]
 exit_to_user_mode_loop+0xb4/0x100 kernel/entry/common.c:177
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
 syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f69178a4670
Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 3a 9b 04 00 e8 25 78 fa ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48
RSP: 002b:00007f6918641bb8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: 0000000000000000 RBX: 00007f69179ac058 RCX: 00007f691787cee9
RDX: 00007f6918641bc0 RSI: 00007f6918641cf0 RDI: 0000000000000021
RBP: 00007f69179ac050 R08: 00007f69186426c0 R09: 00007f69186426c0
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f69179ac05c
R13: 000000000000006e R14: 00007ffea2d31490 R15: 00007ffea2d31578
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/05/17 23:33 linux-6.1.y 4078fa637fcd a12e99e7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in preempt_schedule_thunk
* Struck through repros no longer work on HEAD.