rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-...!: (1 GPs behind) idle=aef/1/0x4000000000000000 softirq=21126/21128 fqs=18 (t=10500 jiffies g=30741 q=1238) rcu: rcu_preempt kthread starved for 10453 jiffies! g30741 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:28904 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: 8115 Comm: syz-executor.1 Not tainted 5.16.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:55 Code: cc cc cc cc eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe RSP: 0018:ffffc90002e57448 EFLAGS: 00010202 RAX: ffff88803a42d201 RBX: 0000000000000dff RCX: 00000000000001bf RDX: 0000000000000dff RSI: ffff88803a429c41 RDI: ffff88803a42de41 RBP: ffff8880749f5a00 R08: 0000000000000001 R09: ffff88803a42dfff R10: ffffed1007485bff R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000dff R15: 0000000000000dff FS: 00007f7e312c9700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2ec37000 CR3: 000000007740a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memcpy include/linux/fortify-string.h:225 [inline] copy_page_from_iter_atomic+0xd01/0x16d0 lib/iov_iter.c:969 generic_perform_write+0x27a/0x510 mm/filemap.c:3762 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: 0033:0x7f7e32974e99 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:00007f7e312c9168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f7e32a88030 RCX: 00007f7e32974e99 RDX: 0000000000000000 RSI: 0000000000000014 RDI: 0000000000000006 RBP: 00007f7e329ceff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd50af844f R14: 00007f7e312c9300 R15: 0000000000022000 NMI backtrace for cpu 0 CPU: 0 PID: 8103 Comm: syz-executor.4 Not tainted 5.16.0-rc5-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:lock_acquire+0x1ef/0x510 kernel/locking/lockdep.c:5605 Code: 7e 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:ffffc90002dc70c8 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff920005b8e1b RCX: ffffffff815ba91f RDX: 1ffff1100565c563 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffff8ff77a9f R10: fffffbfff1feef53 R11: 0000000000000000 R12: 0000000000000001 R13: 0000000000000000 R14: ffff88806d77c538 R15: 0000000000000000 down_read+0x98/0x440 kernel/locking/rwsem.c:1470 ext4_da_map_blocks fs/ext4/inode.c:1709 [inline] ext4_da_get_block_prep+0x7af/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: 0033:0x7f1b0cedae99 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:00007f1b0b850168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f1b0cfedf60 RCX: 00007f1b0cedae99 RDX: 0000000000000000 RSI: 0000000000000014 RDI: 0000000000000006 RBP: 00007f1b0cf34ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffb R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc85ccc18f R14: 00007f1b0b850300 R15: 0000000000022000 BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 272s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 2: cpus=1 node=0 flags=0x0 nice=0 active=12/256 refcnt=13 in-flight: 3684:cache_reap pending: macvlan_process_broadcast, macvlan_process_broadcast, macvlan_process_broadcast, macvlan_process_broadcast, macvlan_process_broadcast, free_work, rht_deferred_worker, macvlan_process_broadcast, macvlan_process_broadcast, macvlan_process_broadcast, macvlan_process_broadcast pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=17/256 refcnt=18 pending: vmstat_shepherd, cache_reap, kfree_rcu_monitor, nsim_dev_trap_report_work, nsim_dev_trap_report_work, nsim_dev_trap_report_work, hci_cmd_timeout, ovs_dp_masks_rebalance, ovs_dp_masks_rebalance, psi_avgs_work, psi_avgs_work, psi_avgs_work, ovs_dp_masks_rebalance, switchdev_deferred_process_work, rht_deferred_worker, rht_deferred_worker, rht_deferred_worker workqueue events_long: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=17/256 refcnt=18 pending: defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, defense_work_handler, br_multicast_gc_work, br_multicast_gc_work, br_multicast_gc_work, br_multicast_gc_work, br_multicast_gc_work, br_fdb_cleanup, br_fdb_cleanup, br_fdb_cleanup, br_fdb_cleanup, br_multicast_gc_work workqueue events_unbound: flags=0x2 pwq 4: cpus=0-1 flags=0x4 nice=0 active=4/512 refcnt=7 ---------------- Code disassembly (best guess): 0: cc int3 1: cc int3 2: cc int3 3: cc int3 4: eb 1e jmp 0x24 6: 0f 1f 00 nopl (%rax) 9: 48 89 f8 mov %rdi,%rax c: 48 89 d1 mov %rdx,%rcx f: 48 c1 e9 03 shr $0x3,%rcx 13: 83 e2 07 and $0x7,%edx 16: f3 48 a5 rep movsq %ds:(%rsi),%es:(%rdi) 19: 89 d1 mov %edx,%ecx 1b: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) 1d: c3 retq 1e: 66 0f 1f 44 00 00 nopw 0x0(%rax,%rax,1) 24: 48 89 f8 mov %rdi,%rax 27: 48 89 d1 mov %rdx,%rcx * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: c3 retq 2d: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 34: 48 89 f8 mov %rdi,%rax 37: 48 83 fa 20 cmp $0x20,%rdx 3b: 72 7e jb 0xbb 3d: 40 38 fe cmp %dil,%sil