rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (10500 ticks this GP) idle=1b5/1/0x4000000000000000 softirq=42866/42866 fqs=5245 (t=10502 jiffies g=68533 q=2296) NMI backtrace for cpu 1 CPU: 1 PID: 22670 Comm: syz-executor.1 Not tainted 5.15.0-next-20211115-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:1421 __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+0x37/0x60 kernel/kcov.c:200 Code: 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 ac 15 00 00 85 c0 74 2b 8b 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 RSP: 0018:ffffc9000499f110 EFLAGS: 00000246 RAX: 0000000000000002 RBX: ffffc9000499f460 RCX: 0000000000000000 RDX: ffff88807dd057c0 RSI: ffffffff81969fca RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: ffff888075f39457 R10: ffffffff81969f21 R11: 0000000000000001 R12: ffffc9000499f260 R13: dffffc0000000000 R14: 0000000000000ba8 R15: 0000000000000010 __output_copy kernel/events/internal.h:178 [inline] perf_output_read_group kernel/events/core.c:6928 [inline] perf_output_read+0xe5a/0x1310 kernel/events/core.c:6961 perf_output_sample+0xd12/0x1d80 kernel/events/core.c:7008 __perf_event_output kernel/events/core.c:7493 [inline] perf_event_output_forward+0x119/0x280 kernel/events/core.c:7507 __perf_event_overflow+0x13c/0x3d0 kernel/events/core.c:9207 perf_swevent_overflow kernel/events/core.c:9283 [inline] perf_swevent_event+0x347/0x550 kernel/events/core.c:9311 do_perf_sw_event kernel/events/core.c:9424 [inline] ___perf_sw_event+0x31a/0x570 kernel/events/core.c:9455 __perf_sw_event+0x54/0x130 kernel/events/core.c:9467 perf_sw_event include/linux/perf_event.h:1174 [inline] mm_account_fault mm/memory.c:4751 [inline] handle_mm_fault+0x5ef/0x790 mm/memory.c:4802 do_user_addr_fault+0x489/0x11c0 arch/x86/mm/fault.c:1397 handle_page_fault arch/x86/mm/fault.c:1485 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1541 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0010:copy_user_enhanced_fast_string+0xe/0x30 arch/x86/lib/copy_user_64.S:206 Code: 89 d1 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 31 c0 0f 01 ca c3 0f 1f 80 00 00 00 00 0f 01 cb 83 fa 40 0f 82 70 ff ff ff 89 d1 a4 31 c0 0f 01 ca c3 66 2e 0f 1f 84 00 00 00 00 00 89 d1 f3 a4 RSP: 0018:ffffc9000499f9b8 EFLAGS: 00050206 RAX: 0000000000000001 RBX: 0000000000008000 RCX: 0000000000002fcb RDX: 0000000000008000 RSI: 0000000020fd2000 RDI: ffff8880269c5035 RBP: ffff8880269c0000 R08: 0000000000000001 R09: ffff8880269c7fff R10: ffffed1004d38fff R11: 0000000000000000 R12: 0000000020fccfcb R13: 0000000020fd4fcb R14: 0000000000000000 R15: ffffc9000499fd70 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:168 copyin lib/iov_iter.c:767 [inline] _copy_from_iter+0x2a3/0x1320 lib/iov_iter.c:767 copy_from_iter include/linux/uio.h:164 [inline] copy_from_iter_full include/linux/uio.h:170 [inline] skb_do_copy_data_nocache include/net/sock.h:2145 [inline] skb_copy_to_page_nocache include/net/sock.h:2171 [inline] tcp_sendmsg_locked+0x12eb/0x3040 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:704 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:724 __sys_sendto+0x21c/0x320 net/socket.c:2036 __do_sys_sendto net/socket.c:2048 [inline] __se_sys_sendto net/socket.c:2044 [inline] __x64_sys_sendto+0xdd/0x1b0 net/socket.c:2044 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: 0033:0x7f78c91c0ae9 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:00007f78c6736188 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007f78c92d3f60 RCX: 00007f78c91c0ae9 RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000006 RBP: 00007f78c921af6d R08: 0000000000000000 R09: 0000000000000053 R10: 00000000fffffff1 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffd68e357af R14: 00007f78c6736300 R15: 0000000000022000 ---------------- Code disassembly (best guess): 0: 81 e1 00 01 00 00 and $0x100,%ecx 6: 65 48 8b 14 25 40 70 mov %gs:0x27040,%rdx d: 02 00 f: a9 00 01 ff 00 test $0xff0100,%eax 14: 74 0e je 0x24 16: 85 c9 test %ecx,%ecx 18: 74 35 je 0x4f 1a: 8b 82 ac 15 00 00 mov 0x15ac(%rdx),%eax 20: 85 c0 test %eax,%eax 22: 74 2b je 0x4f 24: 8b 82 88 15 00 00 mov 0x1588(%rdx),%eax * 2a: 83 f8 02 cmp $0x2,%eax <-- trapping instruction 2d: 75 20 jne 0x4f 2f: 48 8b 8a 90 15 00 00 mov 0x1590(%rdx),%rcx 36: 8b 92 8c 15 00 00 mov 0x158c(%rdx),%edx 3c: 48 8b 01 mov (%rcx),%rax 3f: 48 rex.W