rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=def/1/0x4000000000000000 softirq=56564/56565 fqs=5247 (t=10502 jiffies g=91145 q=1007) NMI backtrace for cpu 0 CPU: 0 PID: 14483 Comm: syz-executor.4 Not tainted 5.16.0-next-20220118-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:604 [inline] check_cpu_stall kernel/rcu/tree_stall.h:688 [inline] rcu_pending kernel/rcu/tree.c:3919 [inline] rcu_sched_clock_irq.cold+0x5c/0x759 kernel/rcu/tree.c:2617 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:__sanitizer_cov_trace_pc+0x5c/0x60 kernel/kcov.c:210 Code: 82 88 15 00 00 83 f8 02 75 20 48 8b 8a 90 15 00 00 8b 92 8c 15 00 00 48 8b 01 48 83 c0 01 48 39 c2 76 07 48 89 34 c1 48 89 01 0f 1f 00 41 55 41 54 49 89 fc 55 48 bd eb 83 b5 80 46 86 c8 61 RSP: 0018:ffffc90004447110 EFLAGS: 00000246 RAX: 0000000000040000 RBX: ffffc90004447460 RCX: ffffc900108ea000 RDX: 0000000000040000 RSI: ffffffff8197c86b RDI: ffff888013db4c70 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff8880197b4f6f R10: ffffffff8197cb04 R11: 0000000000000001 R12: ffffc90004447260 R13: dffffc0000000000 R14: ffff888013db4c60 R15: 0000000000000010 perf_output_read_group kernel/events/core.c:6942 [inline] perf_output_read+0xbcb/0x1310 kernel/events/core.c:6982 perf_output_sample+0xd12/0x1d80 kernel/events/core.c:7029 __perf_event_output kernel/events/core.c:7514 [inline] perf_event_output_forward+0x119/0x280 kernel/events/core.c:7528 __perf_event_overflow+0x13c/0x3d0 kernel/events/core.c:9228 perf_swevent_overflow kernel/events/core.c:9304 [inline] perf_swevent_event+0x347/0x550 kernel/events/core.c:9332 do_perf_sw_event kernel/events/core.c:9445 [inline] ___perf_sw_event+0x31a/0x570 kernel/events/core.c:9476 __perf_sw_event+0x54/0x130 kernel/events/core.c:9488 perf_sw_event include/linux/perf_event.h:1187 [inline] mm_account_fault mm/memory.c:4766 [inline] handle_mm_fault+0x5ef/0x790 mm/memory.c:4817 do_user_addr_fault+0x489/0x11c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1484 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1540 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x40 arch/x86/lib/copy_user_64.S:196 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 8d 0c ca 89 ca eb 20 0f 01 cb 83 fa 40 0f 82 60 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 89 ca eb 06 66 0f 1f 44 00 00 83 f8 12 74 RSP: 0018:ffffc90004447998 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000005fcb RDX: 0000000000008000 RSI: 0000000020ea7000 RDI: ffff88804b1ba035 RBP: ffff88804b1b8000 R08: 0000000000000001 R09: ffff88804b1bffff R10: ffffed1009637fff R11: 0000000000000000 R12: 0000000020ea4fcb R13: 0000000020eacfcb R14: 0000000000000000 R15: ffffc90004447d70 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline] raw_copy_from_user arch/x86/include/asm/uaccess_64.h:52 [inline] copyin.part.0+0xe4/0x110 lib/iov_iter.c:166 copyin lib/iov_iter.c:765 [inline] _copy_from_iter+0x2a3/0x15b0 lib/iov_iter.c:765 copy_from_iter include/linux/uio.h:171 [inline] copy_from_iter_full include/linux/uio.h:177 [inline] skb_do_copy_data_nocache include/net/sock.h:2189 [inline] skb_copy_to_page_nocache include/net/sock.h:2215 [inline] tcp_sendmsg_locked+0x12e9/0x3190 net/ipv4/tcp.c:1334 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1440 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:819 sock_sendmsg_nosec net/socket.c:705 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:725 __sys_sendto+0x21c/0x320 net/socket.c:2040 __do_sys_sendto net/socket.c:2052 [inline] __se_sys_sendto net/socket.c:2048 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2048 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: 0033:0x7f064e69dfe9 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:00007f064d013168 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f064e7b0f60 RCX: 00007f064e69dfe9 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000017 RBP: 00007f064e6f808d R08: 0000000000000000 R09: 0000000000000053 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff88ea9acf R14: 00007f064d013300 R15: 0000000000022000 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 88 15 00 00 83 f8 mov %dl,-0x77d0000(%rip) # 0xf8830006 6: 02 75 20 add 0x20(%rbp),%dh 9: 48 8b 8a 90 15 00 00 mov 0x1590(%rdx),%rcx 10: 8b 92 8c 15 00 00 mov 0x158c(%rdx),%edx 16: 48 8b 01 mov (%rcx),%rax 19: 48 83 c0 01 add $0x1,%rax 1d: 48 39 c2 cmp %rax,%rdx 20: 76 07 jbe 0x29 22: 48 89 34 c1 mov %rsi,(%rcx,%rax,8) 26: 48 89 01 mov %rax,(%rcx) * 29: c3 retq <-- trapping instruction 2a: 0f 1f 00 nopl (%rax) 2d: 41 55 push %r13 2f: 41 54 push %r12 31: 49 89 fc mov %rdi,%r12 34: 55 push %rbp 35: 48 bd eb 83 b5 80 46 movabs $0x61c8864680b583eb,%rbp 3c: 86 c8 61