rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (10500 ticks this GP) idle=21b/1/0x4000000000000000 softirq=63790/63792 fqs=12 (t=10502 jiffies g=97249 q=168) rcu: rcu_preempt kthread starved for 10460 jiffies! g97249 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:28712 pid: 14 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4900 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: 19581 Comm: syz-executor.5 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0xde/0x180 mm/kasan/generic.c:189 Code: 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 48 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 <74> f2 eb d4 41 bc 08 00 00 00 48 89 ea 45 29 dc 4d 8d 1c 2c eb 0c RSP: 0018:ffffc90000fd8c30 EFLAGS: 00000046 RAX: fffffbfff1fef541 RBX: fffffbfff1fef542 RCX: ffffffff815b8b77 RDX: fffffbfff1fef542 RSI: 0000000000000008 RDI: ffffffff8ff7aa08 RBP: fffffbfff1fef541 R08: 0000000000000000 R09: ffffffff8ff7aa0f R10: fffffbfff1fef541 R11: 0000000000000001 R12: ffff888023b76c58 R13: ffff888023b76180 R14: 0000000000000000 R15: 0000000000064000 FS: 00007f115870a700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000076db6000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:71 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline] __lock_acquire+0x1017/0x5470 kernel/locking/lockdep.c:4997 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 clockevents_program_event+0x141/0x370 kernel/time/clockevents.c:326 tick_program_event+0xac/0x140 kernel/time/tick-oneshot.c:44 hrtimer_interrupt+0x36e/0x790 kernel/time/hrtimer.c:1824 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:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605 Code: 96 a6 7e 83 f8 01 0f 85 b4 02 00 00 9c 58 f6 c4 02 0f 85 9f 02 00 00 48 83 7c 24 08 00 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc9000cbe7180 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200197ce32 RCX: 0000000000002cbb RDX: 1ffff1100476ed7b RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8ff7aa17 R10: fffffbfff1fef542 R11: 0000000000000001 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8bcc3760 R15: 0000000000000000 fs_reclaim_acquire mm/page_alloc.c:4552 [inline] fs_reclaim_acquire+0xd2/0x160 mm/page_alloc.c:4543 might_alloc include/linux/sched/mm.h:227 [inline] slab_pre_alloc_hook mm/slab.h:492 [inline] slab_alloc mm/slab.c:3306 [inline] kmem_cache_alloc+0x3d/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: 0033:0x7f1159d94e99 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:00007f115870a168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f1159ea7f60 RCX: 00007f1159d94e99 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004 RBP: 00007f1159deeff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd3ee0c02f R14: 00007f115870a300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 19569 Comm: syz-executor.1 Not tainted 5.16.0-rc7-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+0x5c/0x759 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+0x830/0x1ce0 arch/x86/kernel/unwind_orc.c:466 Code: 07 38 d0 7f 08 84 c0 0f 85 12 12 00 00 41 80 7e 34 00 0f 85 00 fc ff ff 80 3d 56 aa 48 0c 00 0f 85 f3 fb ff ff e9 a6 30 cc 07 <48> b8 00 00 00 00 00 fc ff df 48 8b 54 24 08 48 c1 ea 03 80 3c 02 RSP: 0018:ffffc9000e046f18 EFLAGS: 00000297 RAX: 0000000000000005 RBX: 1ffff92001c08deb RCX: ffffffff8e104e19 RDX: 0000000000000005 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffffffff8e104e14 R09: 0000000000000001 R10: fffff52001c08e09 R11: 000000000008808a R12: ffffc9000e047038 R13: ffffc9000e047025 R14: ffffc9000e046ff0 R15: ffffffff8e104e18 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] jbd2_alloc_handle include/linux/jbd2.h:1603 [inline] new_handle fs/jbd2/transaction.c:481 [inline] jbd2__journal_start+0x191/0x930 fs/jbd2/transaction.c:508 __ext4_journal_start_sb+0x227/0x4a0 fs/ext4/ext4_jbd2.c:105 __ext4_journal_start fs/ext4/ext4_jbd2.h:326 [inline] ext4_dirty_inode+0x9d/0x110 fs/ext4/inode.c:5916 __mark_inode_dirty+0x45b/0xfe0 fs/fs-writeback.c:2399 mark_inode_dirty include/linux/fs.h:2451 [inline] generic_write_end+0x31b/0x500 fs/buffer.c:2202 ext4_da_write_end+0x1c2/0x990 fs/ext4/inode.c:3059 generic_perform_write+0x2c6/0x510 mm/filemap.c:3765 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: 0033:0x7fb5a8f4be99 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:00007fb5a78c1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fb5a905ef60 RCX: 00007fb5a8f4be99 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000004 RBP: 00007fb5a8fa5ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007fffa5ec726f R14: 00007fb5a78c1300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 74 f2 je 0xfffffff4 2: 48 89 c2 mov %rax,%rdx 5: b8 01 00 00 00 mov $0x1,%eax a: 48 85 d2 test %rdx,%rdx d: 75 56 jne 0x65 f: 5b pop %rbx 10: 5d pop %rbp 11: 41 5c pop %r12 13: c3 retq 14: 48 85 d2 test %rdx,%rdx 17: 74 5e je 0x77 19: 48 01 ea add %rbp,%rdx 1c: eb 09 jmp 0x27 1e: 48 83 c0 01 add $0x1,%rax 22: 48 39 d0 cmp %rdx,%rax 25: 74 50 je 0x77 27: 80 38 00 cmpb $0x0,(%rax) * 2a: 74 f2 je 0x1e <-- trapping instruction 2c: eb d4 jmp 0x2 2e: 41 bc 08 00 00 00 mov $0x8,%r12d 34: 48 89 ea mov %rbp,%rdx 37: 45 29 dc sub %r11d,%r12d 3a: 4d 8d 1c 2c lea (%r12,%rbp,1),%r11 3e: eb 0c jmp 0x4c