rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8201/1:b..l (detected by 1, t=10503 jiffies, g=32149, q=464) task:syz.7.1055 state:R running task stack:25928 pid: 8201 ppid: 6907 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc9000331ef60 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 4538d3ef945bac00 RDX: 0000000000000000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340 RBP: ffffc9000331f080 R08: dffffc0000000000 R09: fffffbfff1ff6e19 R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: ffffffff8c11c360 R13: 1ffff92000663df8 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 save_stack+0xf3/0x1e0 mm/page_owner.c:119 __set_page_owner+0x41/0x2d0 mm/page_owner.c:181 prep_new_page mm/page_alloc.c:2426 [inline] get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5474 __page_cache_alloc+0xd2/0x3f0 mm/filemap.c:1022 pagecache_get_page+0x986/0xef0 mm/filemap.c:1940 grab_cache_page_write_begin+0x5c/0xa0 mm/filemap.c:3739 block_write_begin fs/buffer.c:2118 [inline] cont_write_begin+0x56a/0x7b0 fs/buffer.c:2471 fat_write_begin+0xa2/0x170 fs/fat/inode.c:235 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f936b115be9 RSP: 002b:00007f936935c038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f936b33d090 RCX: 00007f936b115be9 RDX: 000000000208e24b RSI: 0000200000000040 RDI: 0000000000000005 RBP: 00007f936b198e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f936b33d128 R14: 00007f936b33d090 R15: 00007ffd1eecffd8 rcu: rcu_preempt kthread starved for 10432 jiffies! g32149 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:27904 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8195 Comm: syz.0.1058 Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__lock_acquire+0xf22/0x7c60 kernel/locking/lockdep.c:5002 Code: 06 b0 01 89 44 24 60 4c 89 b4 24 c8 00 00 00 48 8b 44 24 58 42 0f b6 04 00 84 c0 0f 85 5f 5a 00 00 45 8b 24 24 48 83 7d 10 00 <0f> 84 a3 00 00 00 48 8b 84 24 88 00 00 00 42 0f b6 04 00 84 c0 0f RSP: 0018:ffffc90000007560 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 00000000000600b7 RCX: ffff888020bc8af0 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8ffb70c0 RBP: ffffc900000077b0 R08: dffffc0000000000 R09: fffffbfff1ff6e19 R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: 00000000000a4015 R13: ffff888020bc8000 R14: 1ffff1100417915c R15: 1e40456c94acc51e FS: 00007f4a1e91b6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4a1e91ad00 CR3: 000000004d120000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x197/0x3f0 kernel/locking/lockdep.c:5623 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] is_bpf_text_address+0x1d/0x270 kernel/bpf/core.c:725 kernel_text_address kernel/extable.c:151 [inline] __kernel_text_address+0x9a/0x100 kernel/extable.c:105 unwind_get_return_address+0x49/0x80 arch/x86/kernel/unwind_orc.c:323 arch_stack_walk+0xf2/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:38 [inline] kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:254 [inline] slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519 slab_alloc_node mm/slub.c:3220 [inline] slab_alloc mm/slub.c:3228 [inline] kmem_cache_alloc+0x100/0x290 mm/slub.c:3233 __sigqueue_alloc+0x3a6/0x4b0 kernel/signal.c:435 __send_signal+0x203/0xdb0 kernel/signal.c:1116 do_send_sig_info kernel/signal.c:1294 [inline] group_send_sig_info+0x1c6/0x220 kernel/signal.c:1442 do_bpf_send_signal+0x7b/0x150 kernel/trace/bpf_trace.c:779 irq_work_single kernel/irq_work.c:155 [inline] irq_work_run_list+0x1bb/0x330 kernel/irq_work.c:177 irq_work_run+0x63/0xe0 kernel/irq_work.c:186 __sysvec_irq_work+0x98/0x240 arch/x86/kernel/irq_work.c:22 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x98/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:212 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:156 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:263 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:208 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 3f 5c c7 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc900040cfcb0 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: ffffffff8bbbea20 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed10172067a7 R10: ffffed10172067a7 R11: 1ffff110172067a6 R12: ffff8880b9033b01 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020 arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31 irq_work_queue+0x95/0x140 kernel/irq_work.c:75 bpf_send_signal_common+0x2b2/0x420 kernel/trace/bpf_trace.c:820 ____bpf_send_signal kernel/trace/bpf_trace.c:829 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:827 bpf_prog_7ba5217f62dcd359+0x38/0xa3c bpf_dispatcher_nop_func include/linux/bpf.h:790 [inline] __bpf_prog_run include/linux/filter.h:628 [inline] bpf_prog_run include/linux/filter.h:635 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:1878 [inline] bpf_trace_run2+0x15b/0x2d0 kernel/trace/bpf_trace.c:1915 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18 trace_sys_enter+0x65/0x80 include/trace/events/syscalls.h:18 syscall_trace_enter+0x115/0x180 kernel/entry/common.c:77 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4a20670dd9 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007f4a1e91ab40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f4a208fc098 RCX: 00007f4a20670dd9 RDX: 00007f4a1e91ab40 RSI: 00007f4a1e91ac70 RDI: 0000000000000011 RBP: 00007f4a208fc090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4a208fc128 R14: 00007ffd2d07aab0 R15: 00007ffd2d07ab98