syzbot


INFO: rcu detected stall in syscall_enter_from_user_mode

Status: closed as invalid on 2022/02/08 10:10
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 322d, last: 308d

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=106577, q=124)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295027725-4295017223), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g106577 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:28736 pid:   14 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:4986 [inline]
 __schedule+0xab2/0x4db0 kernel/sched/core.c:6295
 schedule+0xd2/0x260 kernel/sched/core.c:6368
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881
 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1963
 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2136
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </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: 8123 Comm: syz-executor.1 Not tainted 5.17.0-rc1-syzkaller-00316-gdf0001545b27 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:hlock_class kernel/locking/lockdep.c:199 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4700 [inline]
RIP: 0010:__lock_acquire+0x3f1/0x5470 kernel/locking/lockdep.c:4977
Code: 6c 24 18 be 08 00 00 00 81 e5 ff 1f 00 00 48 89 e8 48 c1 f8 06 48 8d 3c c5 40 39 fd 8f e8 77 bc 62 00 48 0f a3 2d ff 41 a0 0e <0f> 83 eb 0c 00 00 48 8d 6c 6d 00 48 c1 e5 06 48 81 c5 60 3d fd 8f
RSP: 0018:ffffc90000007b88 EFLAGS: 00000047
RAX: 0000000000000001 RBX: ffff88803648e160 RCX: ffffffff815cf739
RDX: fffffbfff1ffa754 RSI: 0000000000000008 RDI: ffffffff8ffd3a98
RBP: 0000000000000aef R08: 0000000000000000 R09: ffffffff8ffd3a9f
R10: fffffbfff1ffa753 R11: 0000000000000000 R12: ffff88803648e160
R13: ffff88803648d700 R14: ffff88801e929300 R15: 0000000000044000
FS:  0000555556df8400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000140 CR3: 0000000019071000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 lock_acquire kernel/locking/lockdep.c:5639 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5604
 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:349 [inline]
 advance_sched+0x53/0x9a0 net/sched/sch_taprio.c:714
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:87 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x2b/0x70 kernel/entry/common.c:108
Code: 54 49 89 f4 55 48 89 fd 48 8b 7c 24 10 e8 ed f5 ff ff eb 27 eb 2b e8 24 95 30 f8 e8 5f 93 30 f8 fb 65 48 8b 04 25 00 70 02 00 <48> 8b 70 08 40 f6 c6 3f 75 19 4c 89 e0 5d 41 5c c3 eb 1b 0f 0b eb
RSP: 0018:ffffc9000a7cff28 EFLAGS: 00000202
RAX: ffff88803648d700 RBX: 0000000000000000 RCX: 1ffffffff1b29379
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9000a7cff58 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817eb498 R11: 0000000000000000 R12: 0000000000000003
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 do_syscall_64+0x16/0xb0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f56c3379c9b
Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44
RSP: 002b:00007ffc4e14a470 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 0000000000000011 RCX: 00007f56c3379c9b
RDX: ffffffffffffffb8 RSI: ffffffffffffffff RDI: 0000000000000010
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f56c34de1c0
R10: 00007ffc4e14a390 R11: 0000000000000293 R12: 0000000000000001
R13: 0000000000000000 R14: 0000000000000001 R15: 00007ffc4e14a550
 </TASK>
----------------
Code disassembly (best guess):
   0:	6c                   	insb   (%dx),%es:(%rdi)
   1:	24 18                	and    $0x18,%al
   3:	be 08 00 00 00       	mov    $0x8,%esi
   8:	81 e5 ff 1f 00 00    	and    $0x1fff,%ebp
   e:	48 89 e8             	mov    %rbp,%rax
  11:	48 c1 f8 06          	sar    $0x6,%rax
  15:	48 8d 3c c5 40 39 fd 	lea    -0x7002c6c0(,%rax,8),%rdi
  1c:	8f
  1d:	e8 77 bc 62 00       	callq  0x62bc99
  22:	48 0f a3 2d ff 41 a0 	bt     %rbp,0xea041ff(%rip)        # 0xea04229
  29:	0e
* 2a:	0f 83 eb 0c 00 00    	jae    0xd1b <-- trapping instruction
  30:	48 8d 6c 6d 00       	lea    0x0(%rbp,%rbp,2),%rbp
  35:	48 c1 e5 06          	shl    $0x6,%rbp
  39:	48 81 c5 60 3d fd 8f 	add    $0xffffffff8ffd3d60,%rbp

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2022/01/29 05:48 upstream df0001545b27 495e00c5 .config log report info INFO: rcu detected stall in syscall_enter_from_user_mode
ci-upstream-kasan-gce-selinux-root 2022/01/15 11:26 upstream 112450df61b7 723cfaf0 .config log report info INFO: rcu detected stall in syscall_enter_from_user_mode
* Struck through repros no longer work on HEAD.