rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11557/1:b..l rcu: (detected by 1, t=10502 jiffies, g=35841, q=278 ncpus=2) task:syz.1.1515 state:R running task stack:25544 pid:11557 tgid:11556 ppid:5808 task_flags:0x20400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256 irqentry_exit+0x36/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pmd_none arch/x86/include/asm/pgtable.h:1018 [inline] RIP: 0010:___pte_offset_map+0xaa/0x4f0 mm/pgtable-generic.c:293 Code: 00 4d 85 e4 74 24 e8 75 71 ac ff 4c 89 e2 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02 00 0f 85 0e 04 00 00 49 89 1c 24 51 71 ac ff 49 89 dc 31 ff 49 83 e4 9f 4c 89 e6 e8 b0 6c ac ff RSP: 0018:ffffc9000fd2ef28 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000057c56067 RCX: ffffc9000c739000 RDX: 1ffff92001fa5df2 RSI: ffffffff8210765b RDI: 0000000000000001 RBP: 0000200000869000 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffc9000fd2ef90 R13: ffff88807bb65020 R14: ffffc9000fd2f058 R15: 1ffff92001fa5e07 __pte_offset_map include/linux/mm.h:3125 [inline] __pte_offset_map_lock+0x8d/0x310 mm/pgtable-generic.c:397 pte_offset_map_lock include/linux/mm.h:3140 [inline] follow_page_pte+0xab/0x1390 mm/gup.c:812 follow_pmd_mask mm/gup.c:928 [inline] follow_pud_mask mm/gup.c:967 [inline] follow_p4d_mask mm/gup.c:984 [inline] follow_page_mask mm/gup.c:1023 [inline] __get_user_pages+0x918/0x3530 mm/gup.c:1426 __get_user_pages_locked mm/gup.c:1692 [inline] __gup_longterm_locked+0xa92/0x17e0 mm/gup.c:2476 gup_fast_fallback+0xee2/0x22a0 mm/gup.c:3220 pin_user_pages_fast+0xa7/0xf0 mm/gup.c:3326 iov_iter_extract_user_pages lib/iov_iter.c:1751 [inline] iov_iter_extract_pages+0x3a2/0x1ed0 lib/iov_iter.c:1814 __bio_iov_iter_get_pages block/bio.c:1234 [inline] bio_iov_iter_get_pages+0x395/0x1300 block/bio.c:1356 blkdev_iov_iter_get_pages block/fops.c:49 [inline] __blkdev_direct_IO block/fops.c:222 [inline] blkdev_direct_IO+0x128f/0x2100 block/fops.c:441 blkdev_direct_write block/fops.c:726 [inline] blkdev_write_iter+0x703/0xe00 block/fops.c:794 aio_write+0x3b9/0x910 fs/aio.c:1634 __io_submit_one fs/aio.c:2006 [inline] io_submit_one+0x1243/0x1df0 fs/aio.c:2053 __do_sys_io_submit fs/aio.c:2112 [inline] __se_sys_io_submit fs/aio.c:2082 [inline] __x64_sys_io_submit+0x1a9/0x350 fs/aio.c:2082 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcfb198f749 RSP: 002b:00007fcfb282c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d1 RAX: ffffffffffffffda RBX: 00007fcfb1be5fa0 RCX: 00007fcfb198f749 RDX: 00002000000000c0 RSI: 00000000000000f3 RDI: 00007fcfb280b000 RBP: 00007fcfb1a13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fcfb1be6038 R14: 00007fcfb1be5fa0 R15: 00007ffe1c7f59a8 rcu: rcu_preempt kthread starved for 9557 jiffies! g35841 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:28552 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 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+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 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: a7 6c 02 c3 cc cc cc cc 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 83 55 29 00 fb f4 3c 0a 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197de8 EFLAGS: 000002c6 RAX: 0000000002b264ab RBX: 0000000000000001 RCX: ffffffff8b60d2a9 RDX: 0000000000000000 RSI: ffffffff8da2c59c RDI: ffffffff8bf073c0 RBP: ffffed1003ad6490 R08: 0000000000000001 R09: ffffed10170a6655 R10: ffff8880b85332ab R11: 0000000000000001 R12: 0000000000000001 R13: ffff88801d6b2480 R14: ffffffff908216d0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124b05000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9da4593d58 CR3: 00000000742de000 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:190 [inline] do_idle+0x38d/0x500 kernel/sched/idle.c:330 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148