syzbot


INFO: rcu detected stall in sys_io_uring_enter

Status: closed as invalid on 2022/02/08 10:00
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 391d, last: 381d

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=653/1/0x4000000000000000 softirq=208885/208886 fqs=5238 
	(t=10502 jiffies g=349821 q=28361)
NMI backtrace for cpu 1
CPU: 1 PID: 11524 Comm: syz-executor.5 Not tainted 5.15.0-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+0x1dc/0x2d8 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x45f/0x490 lib/nmi_backtrace.c:105
 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x22d/0x390 kernel/rcu/tree_stall.h:343
 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:711 [inline]
 rcu_pending kernel/rcu/tree.c:3878 [inline]
 rcu_sched_clock_irq+0x1e33/0x2bc0 kernel/rcu/tree.c:2597
 update_process_times+0x197/0x200 kernel/time/timer.c:1785
 tick_sched_handle kernel/time/tick-sched.c:226 [inline]
 tick_sched_timer+0x27d/0x420 kernel/time/tick-sched.c:1421
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4cb/0xa60 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3b3/0x1040 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline]
 __sysvec_apic_timer_interrupt+0xf9/0x270 arch/x86/kernel/apic/apic.c:1103
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1097
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x12/0x20
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:rcu_read_lock_sched_held+0xc3/0x130 kernel/rcu/update.c:125
Code: e0 45 49 c7 04 1e 00 00 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 48 75 6d 44 89 f8 48 8d 65 e0 5b 41 5c 41 5e 41 5f 5d c3 <65> 8b 05 7e 88 94 7e 41 bf 01 00 00 00 a9 ff ff ff 7f 75 bc 4c 8d
RSP: 0018:ffffc90009a46b40 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 1ffff92001348d68 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90009a46bd0 R08: dffffc0000000000 R09: fffffbfff1bfcce6
R10: fffffbfff1bfcce6 R11: 0000000000000000 R12: dffffc0000000000
R13: 1ffff92001348d8c R14: dffffc0000000000 R15: 0000000000000000
 trace_lock_release+0x4f/0x150 include/trace/events/lock.h:58
 lock_release+0x82/0x810 kernel/locking/lockdep.c:5648
 rcu_read_unlock include/linux/rcupdate.h:721 [inline]
 is_bpf_text_address+0x253/0x270 kernel/bpf/core.c:717
 kernel_text_address+0x9e/0xd0 kernel/extable.c:124
 __kernel_text_address+0x9/0x40 kernel/extable.c:78
 unwind_get_return_address+0x48/0x80 arch/x86/kernel/unwind_orc.c:318
 arch_stack_walk+0xf8/0x140 arch/x86/kernel/stacktrace.c:26
 stack_trace_save+0x11b/0x1e0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc+0xdc/0x110 mm/kasan/common.c:513
 kasan_kmalloc include/linux/kasan.h:269 [inline]
 kmem_cache_alloc_trace+0x9d/0x330 mm/slub.c:3261
 kmalloc include/linux/slab.h:590 [inline]
 io_add_buffers fs/io_uring.c:4405 [inline]
 io_provide_buffers fs/io_uring.c:4439 [inline]
 io_issue_sqe+0x328e/0x9830 fs/io_uring.c:6705
 __io_queue_sqe+0x2d/0x780 fs/io_uring.c:6974
 io_queue_sqe fs/io_uring.c:7016 [inline]
 io_submit_sqe fs/io_uring.c:7219 [inline]
 io_submit_sqes+0xffc/0xa7c0 fs/io_uring.c:7325
 __do_sys_io_uring_enter fs/io_uring.c:10039 [inline]
 __se_sys_io_uring_enter+0x21f/0x1cb0 fs/io_uring.c:9981
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fe91ab4fae9
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 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe9180c5188 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fe91ac62f60 RCX: 00007fe91ab4fae9
RDX: 0000000000000000 RSI: 00000000000002ff RDI: 0000000000000003
RBP: 00007fe91aba9f6d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff97a1523f R14: 00007fe9180c5300 R15: 0000000000022000
 </TASK>
----------------
Code disassembly (best guess):
   0:	e0 45                	loopne 0x47
   2:	49 c7 04 1e 00 00 00 	movq   $0x0,(%r14,%rbx,1)
   9:	00
   a:	65 48 8b 04 25 28 00 	mov    %gs:0x28,%rax
  11:	00 00
  13:	48 3b 44 24 48       	cmp    0x48(%rsp),%rax
  18:	75 6d                	jne    0x87
  1a:	44 89 f8             	mov    %r15d,%eax
  1d:	48 8d 65 e0          	lea    -0x20(%rbp),%rsp
  21:	5b                   	pop    %rbx
  22:	41 5c                	pop    %r12
  24:	41 5e                	pop    %r14
  26:	41 5f                	pop    %r15
  28:	5d                   	pop    %rbp
  29:	c3                   	retq
* 2a:	65 8b 05 7e 88 94 7e 	mov    %gs:0x7e94887e(%rip),%eax        # 0x7e9488af <-- trapping instruction
  31:	41 bf 01 00 00 00    	mov    $0x1,%r15d
  37:	a9 ff ff ff 7f       	test   $0x7fffffff,%eax
  3c:	75 bc                	jne    0xfffffffa
  3e:	4c                   	rex.WR
  3f:	8d                   	.byte 0x8d

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-smack-root 2021/11/12 15:39 upstream 5833291ab6de 75b04091 .config log report info INFO: rcu detected stall in sys_io_uring_enter
ci-upstream-kasan-gce-smack-root 2021/11/03 07:06 upstream bfc484fe6abb 17f3edd2 .config log report info INFO: rcu detected stall in sys_io_uring_enter
* Struck through repros no longer work on HEAD.