rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=a17/1/0x4000000000000000 softirq=9578/9579 fqs=8 (t=10500 jiffies g=12621 q=301) rcu: rcu_preempt kthread starved for 10450 jiffies! g12621 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:28720 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 4007 Comm: syz-executor.4 Not tainted 5.16.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_acquire+0x233/0x54a0 kernel/locking/lockdep.c:4961 Code: 75 0c 48 83 7c 24 20 00 0f 85 d4 0c 00 00 4c 03 64 24 28 0f b7 4c 24 10 49 8d 44 24 20 48 89 c2 48 89 44 24 38 66 81 e1 ff 1f <48> b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 84 d2 74 09 RSP: 0018:ffffc90000fd89c0 EFLAGS: 00000006 RAX: ffff888029814bb8 RBX: ffffffff8bba06c8 RCX: 0000000000000042 RDX: ffff888029814bb8 RSI: 000000000000002d RDI: ffff888029814b90 RBP: 0000000000000000 R08: 1ffff11005302972 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888029814b98 R13: ffff8880298140c0 R14: 0000000000000002 R15: 0000000000000001 FS: 00007f62b83e9700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2d03d000 CR3: 0000000078b1f000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire kernel/locking/lockdep.c:5637 [inline] lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602 seqcount_lockdep_reader_access include/linux/seqlock.h:103 [inline] ktime_get+0x7c/0x470 kernel/time/timekeeping.c:827 hrtimer_forward_now include/linux/hrtimer.h:506 [inline] perf_swevent_hrtimer+0x246/0x3f0 kernel/events/core.c:10605 __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_load+0x106/0x140 lib/xarray.c:241 Code: de 48 89 ef e8 eb dc ff ff 49 89 c4 48 89 d8 48 c1 e8 03 42 0f b6 04 28 84 c0 74 02 7e 25 0f b6 1b 31 ff 89 de e8 2a 2f 74 fd <84> db 0f 85 35 ff ff ff e9 4e ff ff ff 48 8b 7c 24 08 e8 03 6d ba RSP: 0018:ffffc90005fcf300 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000006 RCX: ffff8880298140c0 RDX: 0000000000000000 RSI: ffff8880298140c0 RDI: 0000000000000003 RBP: ffffc90005fcf3c0 R08: 0000000000000002 R09: 0000000000000006 R10: ffffffff8402acc6 R11: 0000000000000000 R12: ffff88803c6211c2 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000006 mapping_get_entry mm/filemap.c:1843 [inline] __filemap_get_folio+0x160/0xe10 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:3754 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: 0033:0x7f62b9a73e99 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:00007f62b83e9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f62b9b86f60 RCX: 00007f62b9a73e99 RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000000005 RBP: 00007f62b9acdff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffa R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd45d887ef R14: 00007f62b83e9300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 3995 Comm: syz-executor.1 Not tainted 5.16.0-rc6-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:unwind_next_frame+0x27/0x1ce0 arch/x86/kernel/unwind_orc.c:418 Code: 0f 1f 00 48 b8 00 00 00 00 00 fc ff df 41 57 41 56 49 89 fe 41 55 41 54 55 53 48 81 ec a0 00 00 00 48 c7 44 24 40 b3 8a b5 41 <48> 8d 5c 24 40 48 c7 44 24 48 b9 34 36 8b 48 c1 eb 03 48 c7 44 24 RSP: 0018:ffffc90005ed6e50 EFLAGS: 00000286 RAX: dffffc0000000000 RBX: ffffffff8164e1b0 RCX: 0000000000000000 RDX: 1ffff92000bdae1a RSI: ffffffff81d6be0b RDI: ffffc90005ed6f28 RBP: ffffc90005ed6fb0 R08: 0000000000000001 R09: 0000000000000001 R10: fffff52000bdadf0 R11: 000000000008808a R12: ffffc90005ed6fe0 R13: 0000000000000000 R14: ffffc90005ed6f28 R15: ffff88803c5f7828 arch_stack_walk+0x7d/0xe0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8c/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x1e/0x50 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:434 [inline] __kasan_slab_alloc+0x85/0xb0 mm/kasan/common.c:467 kasan_slab_alloc include/linux/kasan.h:259 [inline] slab_post_alloc_hook mm/slab.h:519 [inline] slab_alloc mm/slab.c:3323 [inline] kmem_cache_alloc+0x265/0x560 mm/slab.c:3507 kmem_cache_zalloc include/linux/slab.h:714 [inline] alloc_buffer_head+0x20/0x140 fs/buffer.c:3309 alloc_page_buffers+0x268/0x5f0 fs/buffer.c:832 create_empty_buffers+0x2c/0x800 fs/buffer.c:1560 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:3754 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: 0033:0x7faa265bde99 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:00007faa24f33168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007faa266d0f60 RCX: 00007faa265bde99 RDX: 0000000000000000 RSI: 000000000000000c RDI: 0000000000000005 RBP: 00007faa26617ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffa R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd36cc851f R14: 00007faa24f33300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 75 0c jne 0xe 2: 48 83 7c 24 20 00 cmpq $0x0,0x20(%rsp) 8: 0f 85 d4 0c 00 00 jne 0xce2 e: 4c 03 64 24 28 add 0x28(%rsp),%r12 13: 0f b7 4c 24 10 movzwl 0x10(%rsp),%ecx 18: 49 8d 44 24 20 lea 0x20(%r12),%rax 1d: 48 89 c2 mov %rax,%rdx 20: 48 89 44 24 38 mov %rax,0x38(%rsp) 25: 66 81 e1 ff 1f and $0x1fff,%cx * 2a: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax <-- trapping instruction 31: fc ff df 34: 48 c1 ea 03 shr $0x3,%rdx 38: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 3c: 84 d2 test %dl,%dl 3e: 74 09 je 0x49