rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=7ddc/1/0x4000000000000000 softirq=101780/101781 fqs=15 rcu: (detected by 0, t=10506 jiffies, g=156669, q=496 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 24859 Comm: syz-executor.2 Not tainted 6.9.0-rc6-syzkaller-00113-g49a73b1652c5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_dynticks_curr_cpu_in_eqs include/linux/context_tracking.h:122 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:700 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 8c 57 7e 00 48 c7 c3 c8 7c 03 00 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 22 8b 03 65 ff 0d d1 6f 87 7e 74 10 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc90000a08c70 EFLAGS: 00000016 RAX: 0000000000000000 RBX: ffff8880b9537cc8 RCX: ffff888028980000 RDX: ffff888028980000 RSI: ffffffff8c1f7ec0 RDI: ffffffff8c1f7e80 RBP: 0000000000000001 R08: ffffffff898a6d42 R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: dffffc0000000000 R13: 17d109b1a4000000 R14: ffffffff8dd4f9e8 R15: dffffc0000000000 FS: 000055555bbf8480(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000f7f4e4 CR3: 0000000064324000 CR4: 0000000000350ef0 Call Trace: rcu_read_lock include/linux/rcupdate.h:782 [inline] advance_sched+0xa3b/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1692 [inline] __hrtimer_run_queues+0x5a7/0xd50 kernel/time/hrtimer.c:1756 hrtimer_interrupt+0x396/0x990 kernel/time/hrtimer.c:1818 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1032 [inline] __sysvec_apic_timer_interrupt+0x112/0x3f0 arch/x86/kernel/apic/apic.c:1049 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1043 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1043 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x6b0/0x2a00 arch/x86/kernel/unwind_orc.c:505 Code: e8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 88 1b 00 00 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 93 1b 00 00 0f b6 5d 01 <83> e3 07 48 89 df 48 c7 c6 80 2f 1a 8e e8 0e c0 54 00 48 85 db 74 RSP: 0018:ffffc90011aa6f08 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000002 RCX: ffff888028980000 RDX: 0000000000000000 RSI: ffffffff8258dd99 RDI: ffffffff8258dba8 RBP: ffffffff903d73aa R08: ffffffff81415480 R09: ffffc90011aa70d0 R10: 0000000000000003 R11: ffffffff8181f000 R12: ffffffff8fc59298 R13: dffffc0000000000 R14: 1ffff92002354dfc R15: ffffffff903d73a6 arch_stack_walk+0x151/0x1b0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3966 [inline] __kmalloc+0x233/0x4a0 mm/slub.c:3979 kmalloc_array include/linux/slab.h:665 [inline] kcalloc include/linux/slab.h:696 [inline] ext4_find_extent+0x36c/0xde0 fs/ext4/extents.c:914 ext4_ext_map_blocks+0x2ec/0x77b0 fs/ext4/extents.c:4143 ext4_map_blocks+0xa5e/0x1d20 fs/ext4/inode.c:623 ext4_getblk+0x1fa/0x850 fs/ext4/inode.c:833 ext4_bread+0x2e/0x180 fs/ext4/inode.c:889 ext4_append+0x327/0x5c0 fs/ext4/namei.c:83 ext4_init_new_dir+0x33e/0xa30 fs/ext4/namei.c:2977 ext4_mkdir+0x4f7/0xcf0 fs/ext4/namei.c:3023 vfs_mkdir+0x2fb/0x4b0 fs/namei.c:4123 do_mkdirat+0x264/0x3a0 fs/namei.c:4146 __do_sys_mkdirat fs/namei.c:4161 [inline] __se_sys_mkdirat fs/namei.c:4159 [inline] __x64_sys_mkdirat+0x89/0xa0 fs/namei.c:4159 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f5c0b07c827 Code: 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 02 01 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fffb9717708 EFLAGS: 00000202 ORIG_RAX: 0000000000000102 RAX: ffffffffffffffda RBX: 00007fffb9717790 RCX: 00007f5c0b07c827 RDX: 00000000000001ff RSI: 00007fffb9717790 RDI: 00000000ffffff9c RBP: 00007fffb971776c R08: 0000000000000004 R09: 00007fffb97174a6 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000032 R13: 000000000010e17f R14: 000000000010e15c R15: 0000000000000002 rcu: rcu_preempt kthread starved for 10430 jiffies! g156669 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:24496 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0x17e8/0x4a50 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6838 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x2df/0x1370 kernel/rcu/tree.c:1663 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:1862 kthread+0x2f2/0x390 kernel/kthread.c:388 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 26925 Comm: syz-executor.0 Not tainted 6.9.0-rc6-syzkaller-00113-g49a73b1652c5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline] RIP: 0010:smp_call_function_many_cond+0x1899/0x2a00 kernel/smp.c:855 Code: 89 e6 83 e6 01 31 ff e8 15 db 0b 00 41 83 e4 01 49 bc 00 00 00 00 00 fc ff df 75 07 e8 c0 d6 0b 00 eb 38 f3 90 42 0f b6 04 23 <84> c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 a4 d6 0b 00 eb e4 44 RSP: 0018:ffffc900046e73e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 1ffff110172a8869 RCX: 0000000000040000 RDX: ffffc9000f8ae000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: ffffc900046e75e0 R08: ffffffff818a39eb R09: 1ffffffff25e6aa0 R10: dffffc0000000000 R11: fffffbfff25e6aa1 R12: dffffc0000000000 R13: ffff8880b9544348 R14: ffff8880b943f7c0 R15: 0000000000000001 FS: 00007f51a45856c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c822000 CR3: 00000000121fc000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2086 [inline] text_poke_bp_batch+0x352/0xb30 arch/x86/kernel/alternative.c:2296 text_poke_bp+0xb0/0x100 arch/x86/kernel/alternative.c:2523 __static_call_transform+0x51a/0x810 arch/x86/kernel/static_call.c:111 arch_static_call_transform+0x141/0x380 arch/x86/kernel/static_call.c:163 __static_call_update+0xd8/0x5e0 kernel/static_call_inline.c:147 tracepoint_update_call kernel/tracepoint.c:317 [inline] tracepoint_add_func+0x918/0x9e0 kernel/tracepoint.c:358 tracepoint_probe_register_prio_may_exist+0x122/0x190 kernel/tracepoint.c:482 bpf_raw_tp_link_attach+0x470/0x6d0 kernel/bpf/syscall.c:3865 bpf_raw_tracepoint_open+0x19d/0x210 kernel/bpf/syscall.c:3892 __sys_bpf+0x3c0/0x810 kernel/bpf/syscall.c:5702 __do_sys_bpf kernel/bpf/syscall.c:5767 [inline] __se_sys_bpf kernel/bpf/syscall.c:5765 [inline] __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5765 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f51a387dd29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f51a45850c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f51a39abf80 RCX: 00007f51a387dd29 RDX: 0000000000000010 RSI: 0000000020000200 RDI: 0000000000000011 RBP: 00007f51a38ca47e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f51a39abf80 R15: 00007ffecf6c0448