rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P10951/1:b..l (detected by 0, t=10502 jiffies, g=66705, q=11 ncpus=2) task:syz.2.1961 state:R running task stack:26496 pid:10951 ppid:4276 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000e12f750 EFLAGS: 00000206 RAX: df4f760b8637b700 RBX: ffff88802b1b3b80 RCX: df4f760b8637b700 RDX: ffff88802b1b3b80 RSI: ffffffff8a8c15e0 RDI: ffffffff8adef320 RBP: 0000000000000001 R08: dffffc0000000000 R09: fffffbfff215ba49 R10: fffffbfff215ba49 R11: 1ffffffff215ba48 R12: 0000000000000002 R13: 0000000000000246 R14: ffffffff8cb2ae20 R15: ffff88802b1b46b0 xa_head include/linux/xarray.h:1182 [inline] xas_start+0x292/0x770 lib/xarray.c:188 xas_load+0x28/0x140 lib/xarray.c:235 mapping_get_entry mm/filemap.c:1881 [inline] __filemap_get_folio+0x1bb/0xdd0 mm/filemap.c:1943 shmem_get_folio_gfp+0x310/0x3400 mm/shmem.c:1881 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0xee/0x3f0 mm/shmem.c:2556 generic_perform_write+0x2db/0x560 mm/filemap.c:3846 __generic_file_write_iter+0x172/0x430 mm/filemap.c:3974 generic_file_write_iter+0xab/0x2e0 mm/filemap.c:4006 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x44c/0x960 fs/read_write.c:584 ksys_write+0x143/0x240 fs/read_write.c:637 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6cee18d69f RSP: 002b:00007f6cef04edf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f6cee18d69f RDX: 0000000001000000 RSI: 00007f6ce3ff7000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005e04 R10: 000020000000c742 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f6cef04eef0 R14: 00007f6cef04eeb0 R15: 00007f6ce3ff7000 rcu: rcu_preempt kthread timer wakeup didn't happen for 10537 jiffies! g66705 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=38450 rcu: rcu_preempt kthread starved for 10543 jiffies! g66705 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27464 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.147-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 c7 c9 b0 f7 e9 4c ff ff ff e8 ed 07 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d 67 85 66 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8c807d88 EFLAGS: 000002c6 RAX: c51ec83efc3d8900 RBX: ffffffff8a201e87 RCX: c51ec83efc3d8900 RDX: 0000000000000001 RSI: ffffffff8a8c0460 RDI: ffffffff8adef320 RBP: ffffffff8c807ec0 R08: dffffc0000000000 R09: ffffed10171c6af6 R10: ffffed10171c6af6 R11: 1ffff110171c6af5 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8c8bc680 R15: 1ffffffff1c3e9b6 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000ff7000 CR3: 000000001777d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1fc/0x570 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 rest_init+0x2dc/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x490/0x539 init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb