rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=10502 jiffies, g=86133, q=43) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4295013342-4295002840), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g86133 f0x2 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:28648 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: 14046 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 RIP: 0010:__lock_release kernel/locking/lockdep.c:5323 [inline] RIP: 0010:lock_release+0x22c/0x720 kernel/locking/lockdep.c:5657 Code: 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 94 04 00 00 <8b> 73 24 85 f6 0f 85 28 04 00 00 48 8d 7b 22 48 b8 00 00 00 00 00 RSP: 0018:ffffc90000fd8b20 EFLAGS: 00000046 RAX: 0000000000000007 RBX: ffff88802a88ad70 RCX: ffffc90000fd8b70 RDX: 0000000000000000 RSI: ffffffff8bba0648 RDI: ffff88802a88ad94 RBP: 1ffff920001fb166 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff8bba0648 R13: 0000000000000003 R14: ffff88802a88ad18 R15: ffff88802a88a2c0 FS: 00007f9dd9528700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2be38000 CR3: 000000007f35c000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: seqcount_lockdep_reader_access include/linux/seqlock.h:104 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get+0x158/0x470 kernel/time/timekeeping.c:829 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: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 f9 a7 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:ffffc9000373f468 EFLAGS: 00000246 RAX: 0000000080000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff819f1ffa RDI: 0000000000000003 RBP: ffffea0002572d80 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff819f1feb R11: 0000000000000000 R12: ffffea0002572d48 R13: ffff888034846588 R14: 0000000005a33000 R15: ffff888034846110 wait_for_stable_page+0x4a/0x70 mm/folio-compat.c:37 ext4_da_write_begin+0x3d5/0xad0 fs/ext4/inode.c:2963 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: 0033:0x7f9ddabb2e99 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:00007f9dd9528168 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f9ddacc5f60 RCX: 00007f9ddabb2e99 RDX: 0000000000000000 RSI: 000000000000000d RDI: 0000000000000005 RBP: 00007f9ddac0cff1 R08: 0000000000000000 R09: 0000000000000000 R10: 00008400fffffffa R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc48ff980f R14: 00007f9dd9528300 R15: 0000000000022000 sched: RT throttling activated ---------------- Code disassembly (best guess): 0: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 7: fc ff df a: 48 89 fa mov %rdi,%rdx d: 48 c1 ea 03 shr $0x3,%rdx 11: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 15: 48 89 f8 mov %rdi,%rax 18: 83 e0 07 and $0x7,%eax 1b: 83 c0 03 add $0x3,%eax 1e: 38 d0 cmp %dl,%al 20: 7c 08 jl 0x2a 22: 84 d2 test %dl,%dl 24: 0f 85 94 04 00 00 jne 0x4be * 2a: 8b 73 24 mov 0x24(%rbx),%esi <-- trapping instruction 2d: 85 f6 test %esi,%esi 2f: 0f 85 28 04 00 00 jne 0x45d 35: 48 8d 7b 22 lea 0x22(%rbx),%rdi 39: 48 rex.W 3a: b8 00 00 00 00 mov $0x0,%eax