rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10498 ticks this GP) idle=8fb/1/0x4000000000000000 softirq=11390/11390 fqs=30 (t=10500 jiffies g=15909 q=116) rcu: rcu_preempt kthread timer wakeup didn't happen for 10428 jiffies! g15909 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=9766 rcu: rcu_preempt kthread starved for 10429 jiffies! g15909 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: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: 4445 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:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x13/0x60 kernel/kcov.c:199 Code: 02 66 0f 1f 44 00 00 48 8b be b0 01 00 00 e8 b4 ff ff ff 31 c0 c3 90 65 8b 05 69 97 8b 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 <65> 48 8b 14 25 40 70 02 00 a9 00 01 ff 00 74 0e 85 c9 74 35 8b 82 RSP: 0018:ffffc90003e77180 EFLAGS: 00000246 RAX: 0000000080000000 RBX: ffff888031438808 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff819cf055 RDI: 0000000000000003 RBP: ffffea0000edbf80 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff819cf542 R11: 0000000000000000 R12: 0000000001101cca R13: 000000000000365e R14: 0000000000000000 R15: 0000000000000000 FS: 00007feb07440700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e63a000 CR3: 000000001cb0b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __filemap_add_folio+0x315/0xe20 mm/filemap.c:913 filemap_add_folio+0xab/0x1d0 mm/filemap.c:999 __filemap_get_folio+0x3bc/0xe10 mm/filemap.c:1962 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: 0033:0x7feb08acae99 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:00007feb07440168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007feb08bddf60 RCX: 00007feb08acae99 RDX: 0000000000000000 RSI: 0000000000000014 RDI: 0000000000000006 RBP: 00007feb08b24ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd41fa773f R14: 00007feb07440300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 4441 Comm: syz-executor.0 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:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline] RIP: 0010:queued_spin_is_locked include/asm-generic/qspinlock.h:28 [inline] RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline] RIP: 0010:do_raw_spin_unlock+0x50/0x230 kernel/locking/spinlock_debug.c:140 Code: 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 bc 01 00 00 81 7d 04 ad 4e ad de 0f 85 74 01 00 00 be 04 00 00 00 48 89 ef e8 00 c3 60 00 <48> 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 0f b6 14 02 48 RSP: 0018:ffffc90003e370a8 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffffff82107fe0 RCX: ffffffff815c5af0 RDX: ffffed10062f1ca6 RSI: 0000000000000004 RDI: ffff88803178e528 RBP: ffff88803178e528 R08: 0000000000000000 R09: ffff88803178e52b R10: ffffed10062f1ca5 R11: 000000000000003f R12: ffff88803178e4a0 R13: ffff88803178e56a R14: 0000000000000002 R15: 000000000000000c __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:389 [inline] __dquot_alloc_space+0x6ed/0xb60 fs/quota/dquot.c:1659 dquot_reserve_block include/linux/quotaops.h:354 [inline] ext4_da_reserve_space+0x123/0x550 fs/ext4/inode.c:1468 ext4_insert_delayed_block fs/ext4/inode.c:1658 [inline] ext4_da_map_blocks fs/ext4/inode.c:1763 [inline] ext4_da_get_block_prep+0xc18/0x11f0 fs/ext4/inode.c:1827 ext4_block_write_begin+0x539/0x1140 fs/ext4/inode.c:1078 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: 0033:0x7f6f8c4dae99 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:00007f6f8ae50168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f6f8c5edf60 RCX: 00007f6f8c4dae99 RDX: 0000000000000000 RSI: 0000000000000014 RDI: 0000000000000006 RBP: 00007f6f8c534ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffe4723254f R14: 00007f6f8ae50300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 6: 48 8b be b0 01 00 00 mov 0x1b0(%rsi),%rdi d: e8 b4 ff ff ff callq 0xffffffc6 12: 31 c0 xor %eax,%eax 14: c3 retq 15: 90 nop 16: 65 8b 05 69 97 8b 7e mov %gs:0x7e8b9769(%rip),%eax # 0x7e8b9786 1d: 89 c1 mov %eax,%ecx 1f: 48 8b 34 24 mov (%rsp),%rsi 23: 81 e1 00 01 00 00 and $0x100,%ecx * 29: 65 48 8b 14 25 40 70 mov %gs:0x27040,%rdx <-- trapping instruction 30: 02 00 32: a9 00 01 ff 00 test $0xff0100,%eax 37: 74 0e je 0x47 39: 85 c9 test %ecx,%ecx 3b: 74 35 je 0x72 3d: 8b .byte 0x8b 3e: 82 .byte 0x82