rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6671/1:b..l rcu: (detected by 0, t=10502 jiffies, g=13473, q=340 ncpus=2) task:syz.4.207 state:R running task stack:26760 pid:6671 tgid:6661 ppid:5831 task_flags:0x400040 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7108 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x25/0x3e0 kernel/locking/lockdep.c:5882 Code: 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 50 6e fb 10 48 89 44 24 28 <0f> 1f 44 00 00 65 8b 05 53 6e fb 10 83 f8 08 0f 83 9a 02 00 00 89 RSP: 0018:ffffc9000c06f410 EFLAGS: 00000282 RAX: fdaea370d23ac900 RBX: ffffffff90651d01 RCX: fdaea370d23ac900 RDX: ffffc9000c06f501 RSI: ffffffff81729af5 RDI: ffffffff8e13ed60 RBP: dffffc0000000000 R08: ffffc9000c06fee0 R09: 0000000000000000 R10: ffffc9000c06f598 R11: fffff5200180deb5 R12: ffffc9000c06fef0 R13: ffffffff81729af5 R14: ffffffff8e13ed60 R15: ffffffff81729af5 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] kmem_cache_alloc_bulk_noprof+0x4e0/0x790 mm/slub.c:5374 __io_alloc_req_refill+0x9d/0x280 io_uring/io_uring.c:972 io_alloc_req io_uring/io_uring.h:449 [inline] io_submit_sqes+0xc31/0x1c50 io_uring/io_uring.c:2326 __do_sys_io_uring_enter io_uring/io_uring.c:3404 [inline] __se_sys_io_uring_enter+0x2df/0x2b20 io_uring/io_uring.c:3338 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3b7158e929 RSP: 002b:00007f3b7239d038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa RAX: ffffffffffffffda RBX: 00007f3b717b6160 RCX: 00007f3b7158e929 RDX: 000000000000e475 RSI: 00000000000075fa RDI: 0000000000000005 RBP: 00007f3b71610b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3b717b6160 R15: 00007ffefd0da228 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g13473 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=10116 rcu: rcu_preempt kthread starved for 10502 jiffies! g13473 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16a2/0x4cb0 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6678 Comm: syz.0.212 Not tainted 6.16.0-rc1-syzkaller-00239-g08215f5486ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:advance_sched+0x3c3/0xc90 net/sched/sch_taprio.c:949 Code: 00 00 00 48 89 1c 24 31 db 4c 8b 6c 24 18 4d 85 ff 0f 85 90 fe ff ff e8 bb 74 41 f8 e9 28 08 00 00 e8 b1 74 41 f8 4c 8b 3c 24 <4c> 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 RSP: 0018:ffffc90000a08c70 EFLAGS: 00000006 RAX: ffffffff897ee68f RBX: 0000000000000000 RCX: ffff888026af5a00 RDX: 0000000000010000 RSI: 0000000000000000 RDI: 18521e1630878407 RBP: 0000000000000002 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200014117c R12: ffff888057636d10 R13: ffff88807bae0000 R14: 18521e1630878407 R15: ffff888057636c00 FS: 00007f71abfab6c0(0000) GS:ffff888125d85000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c34416c CR3: 00000000784b2000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:filemap_map_pages+0x1010/0x1740 mm/filemap.c:3755 Code: 84 db 74 0f e8 e1 f5 c7 ff 4c 89 e7 e8 09 cb 02 00 eb 05 e8 d2 f5 c7 ff 48 8b 74 24 30 44 8b 74 24 5c 8b 44 24 20 09 44 24 04 <48> 8d bc 24 20 01 00 00 48 8b 94 24 98 00 00 00 e8 2b 07 00 00 48 RSP: 0018:ffffc9000f3275e0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffea0001c08d00 RCX: 0000000000080000 RDX: ffffc90004832000 RSI: ffff8880315af930 RDI: 0000000000005d88 RBP: ffffc9000f3277b0 R08: ffffea0001c08d77 R09: 1ffffd40003811ae R10: dffffc0000000000 R11: fffff940003811af R12: ffffea0001c08d40 R13: dffffc0000000000 R14: 0000000000000003 R15: 0000000000001001 do_fault_around mm/memory.c:5568 [inline] do_read_fault mm/memory.c:5601 [inline] do_fault mm/memory.c:5744 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x368a/0x5620 mm/memory.c:6232 handle_mm_fault+0x2d5/0x7f0 mm/memory.c:6401 faultin_page mm/gup.c:1186 [inline] __get_user_pages+0x1af4/0x30b0 mm/gup.c:1488 populate_vma_page_range+0x26b/0x340 mm/gup.c:1926 __mm_populate+0x24c/0x380 mm/gup.c:2029 mm_populate include/linux/mm.h:3348 [inline] vm_mmap_pgoff+0x3f0/0x4c0 mm/util.c:584 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f71ab18e929 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:00007f71abfab038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f71ab3b5fa0 RCX: 00007f71ab18e929 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f71ab210b39 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f71ab3b5fa0 R15: 00007ffe403a0868