rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7242 P7213/1:b..l rcu: (detected by 1, t=10502 jiffies, g=14305, q=358 ncpus=2) task:syz.1.310 state:R running task stack:25528 pid:7213 tgid:7210 ppid:5818 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6855 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7182 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872 Code: f8 0e 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 92 7b ec 0e 0f 82 74 02 00 00 8b 35 0a ac ec 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 a9 f7 0e 12 0f 85 ad 02 00 00 48 83 c4 RSP: 0018:ffffc9000bef71d0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3c95a0 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8da7ce60 RDI: ffffffff8bf1cd00 RBP: 0000000000000002 R08: 000000009a88c1b9 R09: 0000000055087b41 R10: ffff8880342f0b30 R11: 00000000155087b4 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_noprof+0x250/0x720 mm/slub.c:5295 __kernfs_new_node+0xd2/0x8d0 fs/kernfs/dir.c:637 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:713 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1057 sysfs_add_file_mode_ns+0x207/0x3c0 fs/sysfs/file.c:313 create_files fs/sysfs/group.c:76 [inline] internal_create_group+0x578/0xf20 fs/sysfs/group.c:183 internal_create_groups+0x9d/0x150 fs/sysfs/group.c:223 setup_gid_attrs drivers/infiniband/core/sysfs.c:1162 [inline] ib_setup_port_attrs+0x41f/0x600 drivers/infiniband/core/sysfs.c:1439 add_one_compat_dev+0x558/0x7d0 drivers/infiniband/core/device.c:1005 rdma_dev_init_net+0x2b1/0x530 drivers/infiniband/core/device.c:1221 ops_init+0x1e2/0x5f0 net/core/net_namespace.c:137 setup_net+0x11d/0x3a0 net/core/net_namespace.c:445 copy_net_ns+0x351/0x5d0 net/core/net_namespace.c:580 create_new_namespaces+0x3ea/0xab0 kernel/nsproxy.c:130 unshare_nsproxy_namespaces+0xc0/0x1f0 kernel/nsproxy.c:226 ksys_unshare+0x45b/0xa40 kernel/fork.c:3129 __do_sys_unshare kernel/fork.c:3200 [inline] __se_sys_unshare kernel/fork.c:3198 [inline] __x64_sys_unshare+0x31/0x40 kernel/fork.c:3198 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f32f518f749 RSP: 002b:00007f32f5fef038 EFLAGS: 00000246 ORIG_RAX: 0000000000000110 RAX: ffffffffffffffda RBX: 00007f32f53e6180 RCX: 00007f32f518f749 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000066000080 RBP: 00007f32f5213f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f32f53e6218 R14: 00007f32f53e6180 R15: 00007fff08814ff8 task:syz.3.317 state:R running task stack:27016 pid:7242 tgid:7241 ppid:5826 task_flags:0x400140 flags:0x00080000 Call Trace: sched_show_task kernel/sched/core.c:7814 [inline] sched_show_task+0x423/0x630 kernel/sched/core.c:7789 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:681 [inline] check_cpu_stall kernel/rcu/tree_stall.h:856 [inline] rcu_pending kernel/rcu/tree.c:3667 [inline] rcu_sched_clock_irq+0x2435/0x2f60 kernel/rcu/tree.c:2704 update_process_times+0x178/0x2d0 kernel/time/timer.c:2474 tick_sched_handle kernel/time/tick-sched.c:298 [inline] tick_nohz_handler+0x506/0x720 kernel/time/tick-sched.c:319 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x64e/0xc40 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x0/0x20 kernel/kcov.c:313 Code: 0c 24 0f b7 d6 0f b7 f7 bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 89 f2 89 fe bf 05 00 00 00 e9 2a fe ff ff RSP: 0018:ffffc9000c17f7d8 EFLAGS: 00000246 RAX: 0000000000080000 RBX: 0000000000000008 RCX: ffffc9000d3a9000 RDX: 0000000000080000 RSI: 0000000000000008 RDI: 0000000000000060 RBP: 1ffff9200182fefe R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000ffffffff R12: ffffc9000c17f8b0 R13: 0000000000000000 R14: ffff88805887e200 R15: 0000000000000000 ____bpf_snprintf kernel/bpf/helpers.c:1057 [inline] bpf_snprintf+0xce/0x1e0 kernel/bpf/helpers.c:1049 bpf_prog_648d81472c51bdce+0x66/0x6e bpf_dispatcher_nop_func include/linux/bpf.h:1350 [inline] __bpf_prog_run include/linux/filter.h:721 [inline] bpf_prog_run include/linux/filter.h:728 [inline] bpf_test_run+0x3d3/0xa60 net/bpf/test_run.c:423 bpf_prog_test_run_skb+0xbae/0x2290 net/bpf/test_run.c:1091 bpf_prog_test_run kernel/bpf/syscall.c:4688 [inline] __sys_bpf+0x1035/0x4980 kernel/bpf/syscall.c:6167 __do_sys_bpf kernel/bpf/syscall.c:6259 [inline] __se_sys_bpf kernel/bpf/syscall.c:6257 [inline] __x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:6257 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7faf64d8f749 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:00007faf62ff6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007faf64fe5fa0 RCX: 00007faf64d8f749 RDX: 0000000000000050 RSI: 0000200000000480 RDI: 000000000000000a RBP: 00007faf64e13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007faf64fe6038 R14: 00007faf64fe5fa0 R15: 00007ffe65d44338 rcu: rcu_preempt kthread starved for 10597 jiffies! g14305 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:28296 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6855 __schedule_loop kernel/sched/core.c:6937 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6952 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+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 66 76 02 e9 d3 2f 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 d3 2b 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c2 RAX: 0000000000912131 RBX: 0000000000000000 RCX: ffffffff8b5e86f9 RDX: 0000000000000000 RSI: ffffffff8daa2b8e RDI: ffffffff8bf1cd00 RBP: fffffbfff1c12f50 R08: 0000000000000001 R09: ffffed101708672d R10: ffff8880b843396b R11: 00000000ffffffff R12: 0000000000000000 R13: ffffffff8e097a80 R14: ffffffff9085c3d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812499c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30901ff8 CR3: 00000000294d3000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x38d/0x510 kernel/sched/idle.c:332 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430 rest_init+0x16b/0x2b0 init/main.c:757 start_kernel+0x3f6/0x4d0 init/main.c:1111 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x148