syzbot


INFO: rcu detected stall in sys_unshare (6)

Status: auto-closed as invalid on 2022/05/15 15:21
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 291d, last: 291d
similar bugs (5):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_unshare (2) 1 1060d 1060d 0/24 closed as invalid on 2020/01/08 05:23
upstream INFO: rcu detected stall in sys_unshare (5) 1 322d 322d 0/24 closed as invalid on 2022/02/08 10:10
upstream INFO: rcu detected stall in sys_unshare (3) 1 546d 546d 0/24 auto-closed as invalid on 2021/09/03 04:28
upstream INFO: rcu detected stall in sys_unshare 3 1095d 1095d 0/24 closed as invalid on 2019/12/04 14:04
upstream INFO: rcu detected stall in sys_unshare (4) 1 454d 454d 0/24 auto-closed as invalid on 2021/12/03 09:38

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=2ad/1/0x4000000000000000 softirq=76884/76885 fqs=1 
	(t=13808 jiffies g=127321 q=587)
NMI backtrace for cpu 1
CPU: 1 PID: 19386 Comm: syz-executor.4 Not tainted 5.17.0-rc4-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:88 [inline]
 dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x1e6/0x230 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:688 [inline]
 rcu_pending kernel/rcu/tree.c:3919 [inline]
 rcu_sched_clock_irq.cold+0x402/0x755 kernel/rcu/tree.c:2617
 update_process_times+0x16d/0x200 kernel/time/timer.c:1785
 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226
 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x1c0/0xe50 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:unwind_next_frame+0xde3/0x1ce0 arch/x86/kernel/unwind_orc.c:593
Code: d2 0f 95 c2 40 84 d6 0f 85 75 0d 00 00 83 e1 07 38 c8 0f 9e c2 84 c0 0f 95 c0 84 c2 0f 85 60 0d 00 00 41 0f b6 40 04 c0 e8 04 <3c> 01 0f 84 98 05 00 00 3c 04 74 21 84 c0 0f 84 b6 00 00 00 80 3d
RSP: 0018:ffffc9000440f0a0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 1ffff92000881e1c RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffffc9000440f1d0
RBP: 0000000000000001 R08: ffffffff8e11245c R09: 0000000000000001
R10: fffff52000881e3a R11: 0000000000088078 R12: ffffc9000440fe58
R13: ffffc9000440f1ad R14: ffffc9000440f178 R15: ffffffff8e112460
 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x1e/0x40 mm/kasan/common.c:38
 kasan_set_track mm/kasan/common.c:45 [inline]
 set_alloc_info mm/kasan/common.c:436 [inline]
 ____kasan_kmalloc mm/kasan/common.c:515 [inline]
 ____kasan_kmalloc mm/kasan/common.c:474 [inline]
 __kasan_kmalloc+0xa6/0xd0 mm/kasan/common.c:524
 kasan_kmalloc include/linux/kasan.h:270 [inline]
 __do_kmalloc mm/slab.c:3694 [inline]
 __kmalloc_track_caller+0x206/0x4d0 mm/slab.c:3709
 kstrdup+0x36/0x70 mm/util.c:60
 kstrdup_const+0x53/0x80 mm/util.c:83
 __kernfs_new_node+0x9d/0x8b0 fs/kernfs/dir.c:581
 kernfs_new_node+0x93/0x120 fs/kernfs/dir.c:647
 __kernfs_create_file+0x51/0x350 fs/kernfs/file.c:987
 sysfs_add_file_mode_ns+0x20f/0x3f0 fs/sysfs/file.c:294
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x322/0xb10 fs/sysfs/group.c:148
 internal_create_groups.part.0+0x90/0x140 fs/sysfs/group.c:188
 internal_create_groups fs/sysfs/group.c:184 [inline]
 sysfs_create_groups+0x25/0x50 fs/sysfs/group.c:214
 setup_port+0x387/0x1580 drivers/infiniband/core/sysfs.c:1251
 ib_setup_port_attrs+0x1e7/0x5c0 drivers/infiniband/core/sysfs.c:1435
 add_one_compat_dev drivers/infiniband/core/device.c:968 [inline]
 add_one_compat_dev+0x517/0x7f0 drivers/infiniband/core/device.c:919
 rdma_dev_init_net+0x28b/0x480 drivers/infiniband/core/device.c:1184
 ops_init+0xaf/0x470 net/core/net_namespace.c:140
 setup_net+0x554/0xbb0 net/core/net_namespace.c:330
 copy_net_ns+0x318/0x760 net/core/net_namespace.c:474
 create_new_namespaces+0x3f6/0xb20 kernel/nsproxy.c:110
 unshare_nsproxy_namespaces+0xc1/0x1f0 kernel/nsproxy.c:226
 ksys_unshare+0x445/0x920 kernel/fork.c:3048
 __do_sys_unshare kernel/fork.c:3119 [inline]
 __se_sys_unshare kernel/fork.c:3117 [inline]
 __x64_sys_unshare+0x2d/0x40 kernel/fork.c:3117
 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+0x44/0xae
RIP: 0033:0x7f08b9a5c059
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f08b83d1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f08b9b6ef60 RCX: 00007f08b9a5c059
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000042000000
RBP: 00007f08b9ab608d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdb60c2b0f R14: 00007f08b83d1300 R15: 0000000000022000
 </TASK>
hrtimer: interrupt took 138827785636 ns
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	0f 95 c2             	setne  %dl
   3:	40 84 d6             	test   %dl,%sil
   6:	0f 85 75 0d 00 00    	jne    0xd81
   c:	83 e1 07             	and    $0x7,%ecx
   f:	38 c8                	cmp    %cl,%al
  11:	0f 9e c2             	setle  %dl
  14:	84 c0                	test   %al,%al
  16:	0f 95 c0             	setne  %al
  19:	84 c2                	test   %al,%dl
  1b:	0f 85 60 0d 00 00    	jne    0xd81
  21:	41 0f b6 40 04       	movzbl 0x4(%r8),%eax
  26:	c0 e8 04             	shr    $0x4,%al
* 29:	3c 01                	cmp    $0x1,%al <-- trapping instruction
  2b:	0f 84 98 05 00 00    	je     0x5c9
  31:	3c 04                	cmp    $0x4,%al
  33:	74 21                	je     0x56
  35:	84 c0                	test   %al,%al
  37:	0f 84 b6 00 00 00    	je     0xf3
  3d:	80                   	.byte 0x80
  3e:	3d                   	.byte 0x3d

Crashes (1):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-selinux-root 2022/02/14 15:17 upstream 754e0b0e3560 8b9ca619 .config log report info INFO: rcu detected stall in sys_unshare
* Struck through repros no longer work on HEAD.