syzbot


INFO: rcu detected stall in get_random_bytes

Status: auto-obsoleted due to no activity on 2022/12/04 13:33
Subsystems: kernel
[Documentation on labels]
First crash: 599d, last: 599d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P3636/1:b..l
	(detected by 1, t=10503 jiffies, g=258925, q=57 ncpus=2)
task:syz-executor.0  state:R  running task     stack:24624 pid: 3636 ppid:  3628 flags:0x00000000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5182 [inline]
 __schedule+0xadf/0x52b0 kernel/sched/core.c:6494
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:6806
 irqentry_exit+0x31/0x80 kernel/entry/common.c:428
 asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:654
RIP: 0010:__rcu_read_unlock+0xfe/0x570 kernel/rcu/tree_plugin.h:427
Code: 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 5e 01 00 00 <8b> 83 3c 04 00 00 3d ff ff ff 3f 0f 87 38 01 00 00 5b 5d 41 5c 41
RSP: 0018:ffffc9000313fce0 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff888073314100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8174a7ca RDI: ffff88807331453c
RBP: ffff888073314100 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888073314100
R13: ffff8880262c5000 R14: ffff888073314100 R15: 0000000000000001
 rcu_read_unlock include/linux/rcupdate.h:738 [inline]
 percpu_ref_get_many include/linux/percpu-refcount.h:209 [inline]
 percpu_ref_get include/linux/percpu-refcount.h:222 [inline]
 cgroup_bpf_get include/linux/cgroup.h:913 [inline]
 cgroup_sk_alloc+0x21f/0xa50 kernel/cgroup/cgroup.c:6759
 sk_alloc+0x2b4/0x770 net/core/sock.c:2049
 inet6_create net/ipv6/af_inet6.c:185 [inline]
 inet6_create+0x36f/0x1030 net/ipv6/af_inet6.c:112
 __sock_create+0x355/0x790 net/socket.c:1515
 sock_create net/socket.c:1566 [inline]
 __sys_socket_create net/socket.c:1603 [inline]
 __sys_socket_create net/socket.c:1588 [inline]
 __sys_socket+0x12f/0x240 net/socket.c:1636
 __do_sys_socket net/socket.c:1649 [inline]
 __se_sys_socket net/socket.c:1647 [inline]
 __x64_sys_socket+0x6f/0xb0 net/socket.c:1647
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f69dec8a8f7
RSP: 002b:00007ffc94bd4248 EFLAGS: 00000206 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 0000000000000029 RCX: 00007f69dec8a8f7
RDX: 0000000000000006 RSI: 0000000000000001 RDI: 000000000000000a
RBP: 00007ffc94bd4270 R08: 0000000000000000 R09: ffff000000000000
R10: 0000000000000010 R11: 0000000000000206 R12: 0000000000000032
R13: 00000000002daceb R14: 000000000000000d R15: 00007f69ded6bb60
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10500 jiffies! g258925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=230861
rcu: rcu_preempt kthread starved for 10501 jiffies! g258925 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28352 pid:   16 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5182 [inline]
 __schedule+0xadf/0x52b0 kernel/sched/core.c:6494
 schedule+0xda/0x1b0 kernel/sched/core.c:6570
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935
 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1657
 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1854
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6990 Comm: kworker/0:2 Not tainted 6.0.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/26/2022
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:debug_smp_processor_id+0x13/0x20 lib/smp_processor_id.c:60
Code: 28 48 c7 c7 00 e2 48 8a e8 67 86 bb ff e8 d5 d7 cb ff eb a2 0f 1f 00 0f 1f 44 00 00 48 c7 c6 40 e2 48 8a 48 c7 c7 80 e2 48 8a <e9> 78 fe ff ff 0f 1f 84 00 00 00 00 00 55 48 89 fd 0f 1f 44 00 00
RSP: 0018:ffffc90000007e10 EFLAGS: 00000086
RAX: 0000000000000001 RBX: ffff88807481d340 RCX: 0000000000000000
RDX: dffffc0000000000 RSI: ffffffff8a48e240 RDI: ffffffff8a48e280
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffff8880b9a2a640 R14: ffff8880b9a2a540 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555555d29808 CR3: 000000007638d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:121 [inline]
 rcu_is_watching+0xe/0xb0 kernel/rcu/tree.c:718
 rcu_read_lock_held_common kernel/rcu/update.c:108 [inline]
 rcu_read_lock_sched_held+0x1c/0x70 kernel/rcu/update.c:123
 trace_hrtimer_expire_exit include/trace/events/timer.h:282 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0xa1f/0xe40 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1106
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:crng_make_state+0x0/0x7a0 drivers/char/random.c:291
Code: eb 97 e8 d3 e3 16 fd e8 7e f6 ff ff 48 c7 c7 a0 a9 59 8a e8 7f 81 d6 04 e9 7c ff ff ff e8 f8 e1 1a 05 0f 1f 84 00 00 00 00 00 <41> 57 49 89 f7 41 56 49 89 fe 41 55 49 89 d5 41 54 55 53 48 83 ec
RSP: 0018:ffffc90003f0fb10 EFLAGS: 00000286
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000000000
RDX: 0000000000000006 RSI: ffff888074c0c000 RDI: ffffc90003f0fb38
RBP: ffff888074c0c006 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc90003f0fb38 R14: 1ffff920007e1f63 R15: ffff888074c0c000
 _get_random_bytes.part.0+0x95/0x1a0 drivers/char/random.c:364
 _get_random_bytes drivers/char/random.c:360 [inline]
 get_random_bytes+0x2d/0x40 drivers/char/random.c:396
 eth_random_addr include/linux/etherdevice.h:232 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:749 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:799 [inline]
 nsim_dev_trap_report_work+0x34d/0xc50 drivers/net/netdevsim/dev.c:844
 process_one_work+0x991/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/09/05 13:24 upstream 7e18e42e4b28 922294ab .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in get_random_bytes
* Struck through repros no longer work on HEAD.