rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=428c/1/0x4000000000000000 softirq=6157/6158 fqs=5 rcu: (detected by 1, t=10502 jiffies, g=6873, q=66 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 923 Comm: kworker/0:2 Not tainted 6.7.0-rc4-syzkaller-00838-g172db56d90d2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: events linkwatch_event RIP: 0010:constant_test_bit arch/x86/include/asm/bitops.h:206 [inline] RIP: 0010:arch_test_bit arch/x86/include/asm/bitops.h:238 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:142 [inline] RIP: 0010:netif_carrier_ok include/linux/netdevice.h:4249 [inline] RIP: 0010:linkwatch_urgent_event net/core/link_watch.c:116 [inline] RIP: 0010:linkwatch_urgent_event+0x1db/0x380 net/core/link_watch.c:105 Code: fe ff ff e8 e7 b4 10 f9 be 08 00 00 00 4c 89 ef e8 ba 98 67 f9 4c 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 <0f> 85 7e 01 00 00 4c 8b a3 48 01 00 00 31 ff 49 c1 ec 02 41 83 e4 RSP: 0018:ffffc90004287c10 EFLAGS: 00000046 RAX: dffffc0000000000 RBX: ffff888067d18000 RCX: ffffffff8876e0e6 RDX: 1ffff1100cfa3029 RSI: 0000000000000008 RDI: ffff888067d18148 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffed100cfa3029 R10: ffff888067d1814f R11: 0000000000000003 R12: 0000000000000000 R13: ffff888067d18148 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d619174000 CR3: 0000000068bee000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __linkwatch_run_queue+0xd8/0x460 net/core/link_watch.c:224 linkwatch_event+0x8f/0xc0 net/core/link_watch.c:273 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: rcu_preempt kthread starved for 10492 jiffies! g6873 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28752 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5376 [inline] __schedule+0xedb/0x5af0 kernel/sched/core.c:6688 __schedule_loop kernel/sched/core.c:6763 [inline] schedule+0xe9/0x270 kernel/sched/core.c:6778 schedule_timeout+0x137/0x290 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x1ec/0xb10 kernel/rcu/tree.c:1631 rcu_gp_kthread+0x24b/0x380 kernel/rcu/tree.c:1830 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 12 Comm: kworker/u4:1 Not tainted 6.7.0-rc4-syzkaller-00838-g172db56d90d2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x4e9/0x1550 kernel/smp.c:855 Code: 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 ae c0 0b 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 24 0e 00 00 8b 43 08 31 ff 83 e0 01 41 RSP: 0018:ffffc90000117930 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b98441a0 RCX: ffffffff817bd538 RDX: ffff888017e4d940 RSI: ffffffff817bd512 RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000006 R12: ffffed1017308835 R13: 0000000000000001 R14: ffff8880b98441a8 R15: ffff8880b993d8c0 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2c3d4a8440 CR3: 000000000cd77000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2006 [inline] text_poke_bp_batch+0x22b/0x750 arch/x86/kernel/alternative.c:2216 text_poke_flush arch/x86/kernel/alternative.c:2407 [inline] text_poke_flush arch/x86/kernel/alternative.c:2404 [inline] text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2414 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 jump_label_update+0x1d7/0x400 kernel/jump_label.c:829 static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:205 static_key_enable+0x1a/0x20 kernel/jump_label.c:218 toggle_allocation_gate mm/kfence/core.c:830 [inline] toggle_allocation_gate+0xf4/0x250 mm/kfence/core.c:822 process_one_work+0x886/0x15d0 kernel/workqueue.c:2627 process_scheduled_works kernel/workqueue.c:2700 [inline] worker_thread+0x8b9/0x1290 kernel/workqueue.c:2781 kthread+0x2c6/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:242