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INFO: rcu detected stall in sys_io_uring_setup (3)

Status: auto-obsoleted due to no activity on 2026/03/26 06:52
Subsystems: mm
[Documentation on labels]
First crash: 172d, last: 108d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision Error
0f52da76-17ef-413f-9305-d4cc6ff1bac8 repro INFO: rcu detected stall in sys_io_uring_setup (3) 2026/03/07 04:10 2026/03/07 04:10 2026/03/07 04:28 31e9c887f7dc24e04b3ca70d0d54fc34141844b0
Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in sys_io_uring_setup cgroups mm 1 1 983d 983d 0/29 auto-obsoleted due to no activity on 2023/10/03 12:32
linux-5.15 INFO: rcu detected stall in io_uring_setup 1 1 99d 99d 0/3 upstream: reported on 2026/01/03 23:07
upstream INFO: rcu detected stall in sys_io_uring_setup (2) io-uring mm 1 2 489d 533d 0/29 auto-obsoleted due to no activity on 2025/03/10 01:00
upstream INFO: rcu detected stall in io_uring_setup bpf io-uring 1 2 270d 278d 0/29 auto-obsoleted due to no activity on 2025/10/14 19:03

Sample crash report:
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:ab:83:51:f8:e1, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P18797/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=87665, q=1493 ncpus=1)
task:syz.3.2883      state:R  running task     stack:27592 pid:18797 tgid:18792 ppid:17395  task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256
 irqentry_exit+0x36/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:write_comp_data+0x3/0x90 kernel/kcov.c:240
Code: bb 7c e4 11 48 8b 80 70 16 00 00 c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 <49> 89 f8 49 89 f1 65 48 8b 15 87 7c e4 11 65 8b 05 98 7c e4 11 a9
RSP: 0018:ffffc90019b6f708 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 000000000005dfd8 RCX: ffffffff822fbe88
RDX: 0000000000000006 RSI: 000000000000001f RDI: 0000000000000005
RBP: 0000000000000018 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000001 R12: ffff88801e1df380
R13: ffff88801e1df37c R14: 0000000000000006 R15: dffffc0000000000
 __page_table_check_zero+0x1e8/0x5d0 mm/page_table_check.c:139
 page_table_check_alloc include/linux/page_table_check.h:35 [inline]
 post_alloc_hook+0x1af/0x230 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2507
 io_mem_alloc_compound io_uring/memmap.c:30 [inline]
 io_region_allocate_pages io_uring/memmap.c:168 [inline]
 io_create_region+0x736/0xd50 io_uring/memmap.c:224
 io_allocate_scq_urings io_uring/io_uring.c:3617 [inline]
 io_uring_create io_uring/io_uring.c:3858 [inline]
 io_uring_setup+0x1126/0x20e0 io_uring/io_uring.c:3936
 __do_sys_io_uring_setup io_uring/io_uring.c:3970 [inline]
 __se_sys_io_uring_setup io_uring/io_uring.c:3961 [inline]
 __x64_sys_io_uring_setup+0xc2/0x170 io_uring/io_uring.c:3961
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e88b8efc9
RSP: 002b:00007f5e89a4c038 EFLAGS: 00000246 ORIG_RAX: 00000000000001a9
RAX: ffffffffffffffda RBX: 00007f5e88de6090 RCX: 00007f5e88b8efc9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000fff
RBP: 00007f5e88c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5e88de6128 R14: 00007f5e88de6090 R15: 00007ffdedcbf4a8
 </TASK>
rcu: rcu_preempt kthread starved for 1339 jiffies! g87665 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:28696 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7026
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 3410 Comm: kworker/R-bat_e Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: bat_events batadv_tt_purge
RIP: 0010:__local_bh_enable_ip+0xac/0x120 kernel/softirq.c:457
Code: 1d d9 e5 23 12 65 8b 05 d2 e5 23 12 a9 00 ff ff 00 74 4d bf 01 00 00 00 e8 01 c0 0b 00 e8 1c 70 47 00 fb 65 8b 05 b4 e5 23 12 <85> c0 74 52 5b 5d e9 19 0d e3 09 65 8b 05 fe 23 24 12 85 c0 75 9e
RSP: 0018:ffffc90000006e10 EFLAGS: 00000206
RAX: 0000000080000101 RBX: 00000000fffffe01 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff8da26dd3 RDI: ffffffff8bf071c0
RBP: ffffffff8a1f2195 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90822ad7 R11: ffff88815a88bbf8 R12: 1ffff92000000de6
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff88802f4281b8
FS:  0000000000000000(0000) GS:ffff888124a12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005577e7bd1240 CR3: 00000000282cc000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 ip6t_do_table+0xc02/0x1c30 net/ipv6/netfilter/ip6_tables.c:375
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
 nf_hook+0x471/0x7a0 include/linux/netfilter.h:273
 NF_HOOK include/linux/netfilter.h:316 [inline]
 br_nf_forward_ip.part.0+0x5de/0x810 net/bridge/br_netfilter_hooks.c:716
 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:676 [inline]
 br_nf_forward+0xf0f/0x1be0 net/bridge/br_netfilter_hooks.c:773
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
 nf_hook+0x45e/0x780 include/linux/netfilter.h:273
 NF_HOOK include/linux/netfilter.h:316 [inline]
 __br_forward+0x1be/0x5b0 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0xf1/0x180 net/bridge/br_forward.c:191
 br_flood+0x17c/0x650 net/bridge/br_forward.c:238
 br_handle_frame_finish+0x10e6/0x1ec0 net/bridge/br_input.c:229
 br_nf_hook_thresh+0x307/0x410 net/bridge/br_netfilter_hooks.c:1167
 br_nf_pre_routing_finish_ipv6+0x76a/0xfc0 net/bridge/br_netfilter_ipv6.c:154
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x3cd/0x8c0 net/bridge/br_netfilter_ipv6.c:184
 br_nf_pre_routing+0x860/0x15b0 net/bridge/br_netfilter_hooks.c:508
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0xad8/0x14b0 net/bridge/br_input.c:442
 __netif_receive_skb_core.constprop.0+0xa25/0x4bd0 net/core/dev.c:5966
 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6077
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192
 process_backlog+0x439/0x15e0 net/core/dev.c:6544
 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594
 napi_poll net/core/dev.c:7657 [inline]
 net_rx_action+0x97f/0xef0 net/core/dev.c:7784
 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622
 do_softirq kernel/softirq.c:523 [inline]
 do_softirq+0xb2/0xf0 kernel/softirq.c:510
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_tt_global_purge net/batman-adv/translation-table.c:2250 [inline]
 batadv_tt_purge+0x25f/0xb80 net/batman-adv/translation-table.c:3510
 process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3263
 process_scheduled_works kernel/workqueue.c:3346 [inline]
 rescuer_thread+0x620/0xea0 kernel/workqueue.c:3523
 kthread+0x3c5/0x780 kernel/kthread.c:463
 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
net_ratelimit: 13195 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:ab:83:51:f8:e1, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:ab:83:51:f8:e1, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
net_ratelimit: 10825 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:ab:83:51:f8:e1, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:ab:83:51:f8:e1, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:e6:ab:83:51:f8:e1, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/10/23 12:16 upstream 43e9ad0c55a3 c0460fcd .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in sys_io_uring_setup
2025/12/26 06:51 linux-next cc3aa43b44bd d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in io_uring_setup
* Struck through repros no longer work on HEAD.