INFO: rcu detected stall in io_uring_enter (4)

Status: auto-obsoleted due to no activity on 2025/04/03 10:23
Subsystems: io-uring
[Documentation on labels]
First crash: 601d, last: 601d
▶ ▼ Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in io_uring_enter fs 1 23 1669d 1797d 0/29 closed as invalid on 2022/02/08 10:00
linux-6.6 INFO: rcu detected stall in io_uring_enter 1 2 199d 270d 0/2 auto-obsoleted due to no activity on 2026/05/20 01:03
upstream INFO: rcu detected stall in io_uring_enter (2) io-uring 1 1 843d 843d 0/29 auto-obsoleted due to no activity on 2024/08/04 08:24
upstream INFO: rcu detected stall in sys_io_uring_enter (3) mm prio:low 1 55 13d 250d 0/29 upstream: reported on 2025/12/19 15:15
upstream INFO: rcu detected stall in io_uring_enter (3) io-uring 1 1 718d 718d 0/29 auto-obsoleted due to no activity on 2024/12/07 05:42

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P25472/1:b..l P31481/1:b..l
rcu: 	(detected by 0, t=10506 jiffies, g=138349, q=157 ncpus=2)
task:syz.4.6766      state:R  running task     stack:26336 pid:31481 tgid:31480 ppid:26302  flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6935
 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12
 class_preempt_destructor include/linux/preempt.h:480 [inline]
 class_preempt_destructor include/linux/preempt.h:480 [inline]
 migrate_enable+0x203/0x260 kernel/sched/core.c:2403
 bpf_test_timer_leave+0xc8/0x170 net/bpf/test_run.c:57
 bpf_test_timer_continue+0x32e/0x3d0 net/bpf/test_run.c:84
 bpf_test_run+0x3c6/0xa90 net/bpf/test_run.c:438
 bpf_prog_test_run_xdp+0xcca/0x1580 net/bpf/test_run.c:1320
 bpf_prog_test_run kernel/bpf/syscall.c:4402 [inline]
 __sys_bpf+0xfc6/0x49c0 kernel/bpf/syscall.c:5808
 __do_sys_bpf kernel/bpf/syscall.c:5897 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5895 [inline]
 __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5895
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f89a8185d29
RSP: 002b:00007f89a8fb9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f89a8375fa0 RCX: 00007f89a8185d29
RDX: 0000000000000050 RSI: 00000000200011c0 RDI: 000000000000000a
RBP: 00007f89a8201b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f89a8375fa0 R15: 00007ffdec56afc8
 </TASK>
task:syz.0.5253      state:R  running task     stack:26064 pid:25472 tgid:25471 ppid:21121  flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7078
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:122 [inline]
RIP: 0010:lock_is_held_type+0x45/0x150 kernel/locking/lockdep.c:5914
Code: b1 35 05 85 c9 0f 84 dd 00 00 00 65 8b 05 0b d3 d8 74 85 c0 0f 85 ce 00 00 00 65 4c 8b 25 33 20 da 74 41 8b 94 24 dc 0a 00 00 <85> d2 0f 85 b6 00 00 00 48 89 fd 41 89 f6 9c 8f 04 24 fa 48 c7 c7
RSP: 0018:ffffc9000be4f9f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8e1bb900
RBP: 1ffff920017c9f47 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff8880a6452440
R13: 00000000ffffffff R14: 0000000000000000 R15: 0000000000000000
 io_eventfd_grab+0x3a5/0x5e0 io_uring/eventfd.c:103
 io_eventfd_flush_signal+0x1a/0x1b0 io_uring/eventfd.c:130
 __io_commit_cqring_flush+0x163/0x5b0 io_uring/io_uring.c:579
 io_commit_cqring_flush io_uring/io_uring.h:384 [inline]
 io_cq_unlock_post+0x149/0x190 io_uring/io_uring.c:613
 __io_cqring_overflow_flush+0x480/0x680 io_uring/io_uring.c:665
 io_cqring_do_overflow_flush io_uring/io_uring.c:677 [inline]
 io_cqring_wait+0x1422/0x1800 io_uring/io_uring.c:2616
 __do_sys_io_uring_enter+0xf14/0x1620 io_uring/io_uring.c:3439
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7419385d29
RSP: 002b:00007f741a1d4038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007f7419575fa0 RCX: 00007f7419385d29
RDX: 0000000000000003 RSI: 0000000000000001 RDI: 0000000000000003
RBP: 00007f7419401b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7419575fa0 R15: 00007ffe48491288
 </TASK>
rcu: rcu_preempt kthread starved for 10475 jiffies! g138349 f0x0 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:26336 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5369 [inline]
 __schedule+0xe58/0x5ad0 kernel/sched/core.c:6756
 __schedule_loop kernel/sched/core.c:6833 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6848
 schedule_timeout+0x124/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2045
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2247
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 31488 Comm: syz.2.6767 Not tainted 6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x458/0x1300 kernel/smp.c:884
Code: 0c 00 85 ed 74 4d 48 b8 00 00 00 00 00 fc ff df 4d 89 f4 4c 89 f5 49 c1 ec 03 83 e5 07 49 01 c4 83 c5 03 e8 ba 0e 0c 00 f3 90 <41> 0f b6 04 24 40 38 c5 7c 08 84 c0 0f 85 a7 0c 00 00 8b 43 08 31
RSP: 0018:ffffc90012287b88 EFLAGS: 00000246
RAX: 0000000000080000 RBX: ffff8880b8744a40 RCX: ffffc900171a3000
RDX: 0000000000080000 RSI: ffffffff818e0766 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000003 R12: ffffed10170e8949
R13: 0000000000000001 R14: ffff8880b8744a48 R15: ffff8880b863fe40
FS:  00007fa365bd36c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3b7a1a CR3: 0000000035188000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 00000000872c9164 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1051
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:939 [inline]
 flush_tlb_mm_range+0x289/0x330 arch/x86/mm/tlb.c:1025
 tlb_flush arch/x86/include/asm/tlb.h:20 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:465 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:455 [inline]
 tlb_flush_mmu mm/mmu_gather.c:372 [inline]
 tlb_finish_mmu+0x3c9/0x7b0 mm/mmu_gather.c:465
 do_mprotect_pkey+0xa9c/0xcf0 mm/mprotect.c:848
 __do_sys_mprotect mm/mprotect.c:861 [inline]
 __se_sys_mprotect mm/mprotect.c:858 [inline]
 __x64_sys_mprotect+0x78/0xc0 mm/mprotect.c:858
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa368185d29
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa365bd3038 EFLAGS: 00000246 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007fa368376240 RCX: 00007fa368185d29
RDX: 000000000000000c RSI: 0000000000002000 RDI: 0000000020000000
RBP: 00007fa368201b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fa368376240 R15: 00007ffef6e74258
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/01/03 10:19 upstream 0bc21e701a6f d3ccff63 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in io_uring_enter
* Struck through repros no longer work on HEAD.