rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1 GPs behind) idle=499/1/0x4000000000000000 softirq=16056/16058 fqs=17 (t=10502 jiffies g=20749 q=260) rcu: rcu_preempt kthread starved for 10445 jiffies! g20749 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:28944 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4940 kernel/sched/core.c:6253 schedule+0xd2/0x260 kernel/sched/core.c:6326 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1955 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2128 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 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: 10424 Comm: syz-executor.4 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:xas_descend+0x2/0x3b0 lib/xarray.c:202 Code: e8 23 85 bb fd e9 74 fa ff ff 48 8b 7c 24 08 e8 14 85 bb fd e9 ea f6 ff ff e9 7b 8d 0f 05 66 2e 0f 1f 84 00 00 00 00 00 41 57 <41> 56 41 55 41 54 49 89 f4 55 53 48 89 fb e8 cb 49 75 fd 48 8d 7b RSP: 0018:ffffc90002a172f0 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffff88803ef6a140 RCX: ffffc9000449a000 RDX: 0000000000040000 RSI: ffff88803ef6a140 RDI: ffffc90002a173c0 RBP: ffffc90002a173c0 R08: 0000000000001000 R09: 0000000000000006 R10: ffffffff8401bd90 R11: 0000000000000000 R12: ffff88803ef6a142 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000006 FS: 00007f161bb45700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2c43c000 CR3: 000000001999a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: xas_load+0xe5/0x140 lib/xarray.c:240 mapping_get_entry mm/filemap.c:1843 [inline] __filemap_get_folio+0x160/0xd60 mm/filemap.c:1905 pagecache_get_page+0x2c/0x1a0 mm/folio-compat.c:125 ext4_da_write_begin+0x3bc/0xad0 fs/ext4/inode.c:2958 generic_perform_write+0x205/0x510 mm/filemap.c:3756 ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x472/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_iter_write+0x70/0xa0 fs/read_write.c:892 iter_file_splice_write+0x6fa/0xc10 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f161cbcfaf9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f161bb45188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f161cce2f60 RCX: 00007f161cbcfaf9 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 000000000000000d RBP: 00007f161cc29ff7 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff99d3c67f R14: 00007f161bb45300 R15: 0000000000022000 NMI backtrace for cpu 1 CPU: 1 PID: 10423 Comm: syz-executor.0 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x25e/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:627 [inline] check_cpu_stall kernel/rcu/tree_stall.h:711 [inline] rcu_pending kernel/rcu/tree.c:3878 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2597 update_process_times+0x16d/0x200 kernel/time/timer.c:1785 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:226 tick_sched_timer+0x1b0/0x2d0 kernel/time/tick-sched.c:1428 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x1c0/0xe50 kernel/time/hrtimer.c:1749 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1086 [inline] __sysvec_apic_timer_interrupt+0x146/0x530 arch/x86/kernel/apic/apic.c:1103 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:do_raw_spin_lock+0x0/0x2b0 kernel/locking/spinlock_debug.c:113 Code: b2 b4 07 48 89 74 24 08 4c 89 0c 24 e8 09 ba 60 00 48 8b 74 24 08 4c 8b 0c 24 eb b3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 <48> b8 00 00 00 00 00 fc ff df 41 56 41 55 41 54 55 48 89 fd 48 83 RSP: 0018:ffffc90003627340 EFLAGS: 00000282 RAX: ffffffff81d88a6c RBX: ffff88808349c5b0 RCX: ffffffff815ba8bf RDX: 1ffff1100f920153 RSI: 0000000000000001 RDI: ffff88803b8597d8 RBP: ffffea00020fc700 R08: 0000000000000000 R09: ffffffff8ff76a5f R10: fffffbfff1feed4b R11: 000000000008808a R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: ffffea00020fc700 spin_lock include/linux/spinlock.h:349 [inline] create_empty_buffers+0xbc/0x800 fs/buffer.c:1569 ext4_block_write_begin+0xd1d/0x1140 fs/ext4/inode.c:1060 ext4_da_write_begin+0x3eb/0xad0 fs/ext4/inode.c:2966 generic_perform_write+0x205/0x510 mm/filemap.c:3756 ext4_buffered_write_iter+0x1ac/0x3b0 fs/ext4/file.c:269 ext4_file_write_iter+0x423/0x14e0 fs/ext4/file.c:681 call_write_iter include/linux/fs.h:2162 [inline] do_iter_readv_writev+0x472/0x750 fs/read_write.c:725 do_iter_write+0x188/0x710 fs/read_write.c:851 vfs_iter_write+0x70/0xa0 fs/read_write.c:892 iter_file_splice_write+0x6fa/0xc10 fs/splice.c:689 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0xaf2/0x1250 fs/read_write.c:1245 __do_sys_sendfile64 fs/read_write.c:1310 [inline] __se_sys_sendfile64 fs/read_write.c:1296 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1296 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f8642c38af9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8641bae188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f8642d4bf60 RCX: 00007f8642c38af9 RDX: 0000000000000000 RSI: 0000000000000010 RDI: 000000000000000e RBP: 00007f8642c92ff7 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd33afcaef R14: 00007f8641bae300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: e8 23 85 bb fd callq 0xfdbb8528 5: e9 74 fa ff ff jmpq 0xfffffa7e a: 48 8b 7c 24 08 mov 0x8(%rsp),%rdi f: e8 14 85 bb fd callq 0xfdbb8528 14: e9 ea f6 ff ff jmpq 0xfffff703 19: e9 7b 8d 0f 05 jmpq 0x50f8d99 1e: 66 2e 0f 1f 84 00 00 nopw %cs:0x0(%rax,%rax,1) 25: 00 00 00 28: 41 57 push %r15 * 2a: 41 56 push %r14 <-- trapping instruction 2c: 41 55 push %r13 2e: 41 54 push %r12 30: 49 89 f4 mov %rsi,%r12 33: 55 push %rbp 34: 53 push %rbx 35: 48 89 fb mov %rdi,%rbx 38: e8 cb 49 75 fd callq 0xfd754a08 3d: 48 rex.W 3e: 8d .byte 0x8d 3f: 7b .byte 0x7b