rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=333/1/0x4000000000000000 softirq=7004/7005 fqs=5 (t=10500 jiffies g=7625 q=419) rcu: rcu_preempt kthread timer wakeup didn't happen for 10487 jiffies! g7625 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=5643 rcu: rcu_preempt kthread starved for 10488 jiffies! g7625 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:28648 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4986 [inline] __schedule+0xab2/0x4e90 kernel/sched/core.c:6296 schedule+0xd2/0x260 kernel/sched/core.c:6369 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1881 rcu_gp_fqs_loop+0x186/0x810 kernel/rcu/tree.c:1971 rcu_gp_kthread+0x1de/0x320 kernel/rcu/tree.c:2144 kthread+0x2e9/0x3a0 kernel/kthread.c:377 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4046 Comm: syz-executor.4 Not tainted 5.16.0-rc6-next-20211224-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:asm_sysvec_apic_timer_interrupt+0x0/0x20 arch/x86/include/asm/idtentry.h:637 Code: 00 66 0f 1f 84 00 00 00 00 00 0f 01 ca 6a ff e8 86 03 00 00 48 89 e7 e8 4e 84 f5 ff e9 29 04 00 00 66 0f 1f 84 00 00 00 00 00 <0f> 01 ca 6a ff e8 66 03 00 00 48 89 e7 e8 ae 82 f5 ff e9 09 04 00 RSP: 0018:ffffc9000b6eef88 EFLAGS: 00000086 RAX: 00000000a42c90b8 RBX: 00000000710a7f13 RCX: ffffc9000b6ef0b0 RDX: 000000000000001a RSI: 0000000000000010 RDI: 00000000e86bde5a RBP: ffff88803432c000 R08: 0000000025b53be6 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000800 R14: ffffc9000b6ef020 R15: 000000000000001a FS: 00007f3218515700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b3303a000 CR3: 000000007649c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: RIP: 0010:jhash2 include/linux/jhash.h:129 [inline] RIP: 0010:hash_stack lib/stackdepot.c:203 [inline] RIP: 0010:__stack_depot_save+0xaa/0x500 lib/stackdepot.c:365 Code: 00 00 89 fb 89 f8 4c 89 f1 03 59 08 83 ee 03 48 83 c1 0c 44 8b 41 f4 03 41 f8 41 29 d8 41 01 f8 89 df 01 c3 c1 c7 04 44 31 c7 <29> f8 41 89 c0 89 f8 01 df c1 c0 06 44 31 c0 29 c3 41 89 d8 89 c3 RSP: 0018:ffffc9000b6eefb0 EFLAGS: 00000286 kasan_save_stack+0x2e/0x40 mm/kasan/common.c:39 kasan_set_track+0x21/0x30 mm/kasan/common.c:45 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:370 ____kasan_slab_free mm/kasan/common.c:366 [inline] ____kasan_slab_free+0x166/0x1a0 mm/kasan/common.c:328 kasan_slab_free include/linux/kasan.h:236 [inline] slab_free_hook mm/slub.c:1728 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1754 slab_free mm/slub.c:3509 [inline] kmem_cache_free+0xdb/0x3b0 mm/slub.c:3526 jbd2_free_handle include/linux/jbd2.h:1608 [inline] jbd2_journal_stop+0x656/0xf20 fs/jbd2/transaction.c:1937 __ext4_journal_stop+0xde/0x1f0 fs/ext4/ext4_jbd2.c:127 ext4_dirty_inode+0xe8/0x110 fs/ext4/inode.c:5927 __mark_inode_dirty+0x45b/0xfe0 fs/fs-writeback.c:2409 mark_inode_dirty include/linux/fs.h:2372 [inline] generic_write_end+0x3ea/0x6e0 fs/buffer.c:2240 ext4_da_write_end+0x1c2/0x990 fs/ext4/inode.c:3060 generic_perform_write+0x2c6/0x510 mm/filemap.c:3820 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:2079 [inline] do_iter_readv_writev+0x47a/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+0x723/0xc70 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: 0033:0x7f3219b9fe99 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:00007f3218515168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f3219cb2f60 RCX: 00007f3219b9fe99 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000005 RBP: 00007f3219bf9ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe2514c50f R14: 00007f3218515300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 4042 Comm: syz-executor.2 Not tainted 5.16.0-rc6-next-20211224-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+0x262/0x3f0 kernel/rcu/tree_stall.h:343 print_cpu_stall kernel/rcu/tree_stall.h:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3920 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2625 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:xas_invalid include/linux/xarray.h:1416 [inline] RIP: 0010:xas_valid include/linux/xarray.h:1427 [inline] RIP: 0010:xas_start+0x29/0x730 lib/xarray.c:183 Code: 90 41 56 41 55 41 54 55 53 48 89 fb e8 70 29 68 fd 4c 8d 6b 18 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 80 3c 02 00 <0f> 85 35 06 00 00 48 8b 6b 18 31 ff 49 89 ec 41 83 e4 03 4c 89 e6 RSP: 0018:ffffc9000b1a7518 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: ffffc9000b1a75e8 RCX: ffffc90003efa000 RDX: 1ffff92001634ec0 RSI: ffffffff840fdb10 RDI: ffffc9000b1a75e8 RBP: ffffc9000b1a75e8 R08: 0000000000000000 R09: 0000000000000001 R10: ffffffff819e4933 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc9000b1a7600 R14: dffffc0000000000 R15: ffffc9000b1a75e8 xas_load+0x28/0x140 lib/xarray.c:233 filemap_get_read_batch+0x10e/0x9b0 mm/filemap.c:2393 filemap_get_pages+0x1ef/0x17c0 mm/filemap.c:2598 filemap_read+0x323/0xc70 mm/filemap.c:2689 generic_file_read_iter+0x3b6/0x5a0 mm/filemap.c:2835 ext4_file_read_iter+0x1d4/0x5d0 fs/ext4/file.c:130 call_read_iter include/linux/fs.h:2073 [inline] generic_file_splice_read+0x45b/0x6d0 fs/splice.c:311 do_splice_to+0x1bf/0x250 fs/splice.c:796 splice_direct_to_actor+0x2c2/0x8c0 fs/splice.c:870 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: 0033:0x7f3c78b2de99 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:00007f3c774a3168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f3c78c40f60 RCX: 00007f3c78b2de99 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000005 RBP: 00007f3c78b87ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff092ef6ff R14: 00007f3c774a3300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 7: 00 00 9: 0f 01 ca clac c: 6a ff pushq $0xffffffffffffffff e: e8 86 03 00 00 callq 0x399 13: 48 89 e7 mov %rsp,%rdi 16: e8 4e 84 f5 ff callq 0xfff58469 1b: e9 29 04 00 00 jmpq 0x449 20: 66 0f 1f 84 00 00 00 nopw 0x0(%rax,%rax,1) 27: 00 00 * 29: 0f 01 ca clac <-- trapping instruction 2c: 6a ff pushq $0xffffffffffffffff 2e: e8 66 03 00 00 callq 0x399 33: 48 89 e7 mov %rsp,%rdi 36: e8 ae 82 f5 ff callq 0xfff582e9 3b: e9 .byte 0xe9 3c: 09 04 00 or %eax,(%rax,%rax,1)