rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3192/1:b..l (detected by 0, t=10502 jiffies, g=234965, q=54) task:kworker/u4:19 state:R running task stack:26312 pid: 3192 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:4972 [inline] __schedule+0xa9a/0x4900 kernel/sched/core.c:6253 preempt_schedule_notrace+0x5b/0xd0 kernel/sched/core.c:6498 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:36 rcu_read_unlock_sched_notrace include/linux/rcupdate.h:810 [inline] trace_lock_acquire include/trace/events/lock.h:13 [inline] lock_acquire+0x458/0x510 kernel/locking/lockdep.c:5608 rcu_lock_acquire include/linux/rcupdate.h:268 [inline] rcu_read_lock include/linux/rcupdate.h:688 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x12d/0xfa0 net/batman-adv/network-coding.c:723 process_one_work+0x9b2/0x1660 kernel/workqueue.c:2298 worker_thread+0x65d/0x1130 kernel/workqueue.c:2445 kthread+0x405/0x4f0 kernel/kthread.c:327 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 10497 jiffies! g234965 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:28888 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: 12213 Comm: syz-executor.0 Not tainted 5.16.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__pvclock_read_cycles arch/x86/include/asm/pvclock.h:85 [inline] RIP: 0010:pvclock_clocksource_read+0x177/0x530 arch/x86/kernel/pvclock.c:76 Code: c1 ef 03 0f b6 3c 2f 89 d1 44 38 de 41 0f 9e c3 40 84 f6 40 0f 95 c6 41 84 f3 0f 85 38 03 00 00 48 8b 34 24 83 e6 07 40 38 f7 <40> 0f 9e c6 40 84 ff 40 0f 95 c7 40 84 fe 0f 85 1a 03 00 00 85 d2 RSP: 0018:ffffc90000fd8ee0 EFLAGS: 00000093 RAX: 00000370388b2164 RBX: ffffffff8f173040 RCX: 00000000ffffffff RDX: 00000000ffffffff RSI: 0000000000000003 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff8f173058 R09: ffffffff8f17304f R10: ffffffff8f173057 R11: 0000000000000001 R12: ffffffff8f173043 R13: fffffbfff1e2e609 R14: ffffffff8f17305d R15: ffffffff8f173050 FS: 00007fee7ccbc700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fe3b000 CR3: 000000001c9aa000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000001000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvm_clock_read arch/x86/kernel/kvmclock.c:79 [inline] kvm_sched_clock_read+0x14/0x40 arch/x86/kernel/kvmclock.c:91 sched_clock_cpu+0x15/0x1f0 kernel/sched/clock.c:371 irqtime_account_irq+0x73/0x2d0 kernel/sched/cputime.c:61 sysvec_apic_timer_interrupt+0x86/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:166 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:200 Code: 48 89 ef 5d e9 d1 c0 45 00 5d be 03 00 00 00 e9 b6 35 64 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 f9 a7 8b 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc9000b6374c0 EFLAGS: 00000246 RAX: 0000000000040000 RBX: 0000000000000200 RCX: ffffc90002b90000 RDX: 0000000000040000 RSI: ffffffff8166af7a RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffffffff8ff7aa9f R10: ffffffff8166af70 R11: 0000000000000001 R12: ffffc9000b637540 R13: fffff520016c6ea9 R14: fffff520016c6ea8 R15: ffffc9000b637860 __seqprop_raw_spinlock_sequence include/linux/seqlock.h:276 [inline] ktime_get_coarse_real_ts64+0xd0/0x200 kernel/time/timekeeping.c:2240 current_time+0x72/0x2c0 fs/inode.c:2324 file_update_time+0x119/0x520 fs/inode.c:1995 file_modified fs/inode.c:2035 [inline] file_modified+0x7d/0xa0 fs/inode.c:2020 ext4_write_checks fs/ext4/file.c:247 [inline] ext4_buffered_write_iter+0xff/0x3b0 fs/ext4/file.c:264 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: 0033:0x7fee7e346e99 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:00007fee7ccbc168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007fee7e459f60 RCX: 00007fee7e346e99 RDX: 0000000000000000 RSI: 000000000000000e RDI: 0000000000000005 RBP: 00007fee7e3a0ff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffa R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd056b7b8f R14: 00007fee7ccbc300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: c1 ef 03 shr $0x3,%edi 3: 0f b6 3c 2f movzbl (%rdi,%rbp,1),%edi 7: 89 d1 mov %edx,%ecx 9: 44 38 de cmp %r11b,%sil c: 41 0f 9e c3 setle %r11b 10: 40 84 f6 test %sil,%sil 13: 40 0f 95 c6 setne %sil 17: 41 84 f3 test %sil,%r11b 1a: 0f 85 38 03 00 00 jne 0x358 20: 48 8b 34 24 mov (%rsp),%rsi 24: 83 e6 07 and $0x7,%esi 27: 40 38 f7 cmp %sil,%dil * 2a: 40 0f 9e c6 setle %sil <-- trapping instruction 2e: 40 84 ff test %dil,%dil 31: 40 0f 95 c7 setne %dil 35: 40 84 fe test %dil,%sil 38: 0f 85 1a 03 00 00 jne 0x358 3e: 85 d2 test %edx,%edx