rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (10276 ticks this GP) idle=73f/1/0x4000000000000000 softirq=8936/8939 fqs=3830 (t=10501 jiffies g=8457 q=4130) NMI backtrace for cpu 0 CPU: 0 PID: 8686 Comm: syz-executor159 Not tainted 5.14.0-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:105 nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1ae/0x220 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:3880 [inline] rcu_sched_clock_irq.cold+0x9d/0x746 kernel/rcu/tree.c:2599 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+0x40/0xc0 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:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:197 Code: 01 f0 4d 89 03 e9 63 fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 <65> 8b 05 39 d2 8b 7e 89 c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b RSP: 0018:ffffc90000007cc8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000000100 RDX: ffff888026c01c80 RSI: ffffffff8166647f RDI: 0000000000000003 RBP: 0000000000010406 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff81666475 R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8b99ee08 R15: ffff88807eb31450 __seqprop_raw_spinlock_sequence include/linux/seqlock.h:276 [inline] timekeeping_get_delta kernel/time/timekeeping.c:252 [inline] timekeeping_get_ns kernel/time/timekeeping.c:386 [inline] ktime_get_with_offset+0x1f5/0x500 kernel/time/timekeeping.c:872 ktime_get_real include/linux/timekeeping.h:79 [inline] mac80211_hwsim_get_tsf_raw drivers/net/wireless/mac80211_hwsim.c:977 [inline] mac80211_hwsim_beacon_tx+0x2e6/0x930 drivers/net/wireless/mac80211_hwsim.c:1823 __iterate_interfaces+0x1e5/0x520 net/mac80211/util.c:793 ieee80211_iterate_active_interfaces_atomic+0x70/0x180 net/mac80211/util.c:829 mac80211_hwsim_beacon+0xd5/0x1a0 drivers/net/wireless/mac80211_hwsim.c:1861 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x609/0xe50 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x17b/0x360 kernel/time/hrtimer.c:1766 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558 invoke_softirq kernel/softirq.c:432 [inline] __irq_exit_rcu+0x123/0x180 kernel/softirq.c:636 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638 RIP: 0010:check_kcov_mode kernel/kcov.c:163 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x7/0x60 kernel/kcov.c:197 Code: fd ff ff b9 ff ff ff ff ba 08 00 00 00 4d 8b 03 48 0f bd ca 49 8b 45 00 48 63 c9 e9 64 ff ff ff 0f 1f 00 65 8b 05 39 d2 8b 7e <89> c1 48 8b 34 24 81 e1 00 01 00 00 65 48 8b 14 25 40 f0 01 00 a9 RSP: 0018:ffffc9000209f670 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff888026c01c80 RDI: 0000000000000003 RBP: ffffea0001bfbd80 R08: 0000000000000000 R09: ffffea0001bfbd87 R10: ffffffff81a015d3 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffea0001bfbd88 R15: ffff888071089a90 _compound_head include/linux/page-flags.h:189 [inline] get_page include/linux/mm.h:1209 [inline] lru_cache_add+0x241/0xa70 mm/swap.c:449 do_anonymous_page mm/memory.c:3807 [inline] handle_pte_fault mm/memory.c:4556 [inline] __handle_mm_fault+0x35e6/0x5320 mm/memory.c:4693 handle_mm_fault+0x1c8/0x790 mm/memory.c:4791 do_user_addr_fault+0x48b/0x11c0 arch/x86/mm/fault.c:1390 handle_page_fault arch/x86/mm/fault.c:1475 [inline] exc_page_fault+0x9e/0x180 arch/x86/mm/fault.c:1531 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:568 RIP: 0010:__clear_user+0x40/0x70 arch/x86/lib/usercopy_64.c:24 Code: c5 e7 89 e8 d2 ad b2 fd 0f 01 cb 48 89 d8 48 c1 eb 03 48 89 ef 83 e0 07 48 89 d9 48 85 c9 74 19 66 2e 0f 1f 84 00 00 00 00 00 <48> c7 07 00 00 00 00 48 83 c7 08 ff c9 75 f1 48 89 c1 85 c9 74 0a RSP: 0018:ffffc9000209f9b0 EFLAGS: 00050206 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 000000000000008b RDX: ffff888026c01c80 RSI: ffffffff83f80a6e RDI: 0000000020f6cfff RBP: 0000000020f6c457 R08: 0000000000000000 R09: ffffffff8d6e6ad7 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000020f6d457 R13: 0000000020f6c457 R14: dffffc0000000000 R15: 0000000000000000 clear_user+0xd3/0x110 arch/x86/lib/usercopy_64.c:54 iov_iter_zero+0x1bf/0x14a0 lib/iov_iter.c:896 read_iter_zero+0x10f/0x250 drivers/char/mem.c:492 call_read_iter include/linux/fs.h:2157 [inline] do_iter_readv_writev+0x56d/0x750 fs/read_write.c:727 do_iter_read+0x2f8/0x760 fs/read_write.c:790 vfs_readv+0xe5/0x150 fs/read_write.c:910 do_readv+0x139/0x300 fs/read_write.c:947 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: 0033:0x4411e9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffe1efc0218 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000004411e9 RDX: 000000000000000a RSI: 0000000020001900 RDI: 0000000000000005 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000c00000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 00007ffe1efc0280 R14: 00007ffe1efc0270 R15: 00000000004b83f0 ---------------- Code disassembly (best guess): 0: 01 f0 add %esi,%eax 2: 4d 89 03 mov %r8,(%r11) 5: e9 63 fd ff ff jmpq 0xfffffd6d a: b9 ff ff ff ff mov $0xffffffff,%ecx f: ba 08 00 00 00 mov $0x8,%edx 14: 4d 8b 03 mov (%r11),%r8 17: 48 0f bd ca bsr %rdx,%rcx 1b: 49 8b 45 00 mov 0x0(%r13),%rax 1f: 48 63 c9 movslq %ecx,%rcx 22: e9 64 ff ff ff jmpq 0xffffff8b 27: 0f 1f 00 nopl (%rax) * 2a: 65 8b 05 39 d2 8b 7e mov %gs:0x7e8bd239(%rip),%eax # 0x7e8bd26a <-- trapping instruction 31: 89 c1 mov %eax,%ecx 33: 48 8b 34 24 mov (%rsp),%rsi 37: 81 e1 00 01 00 00 and $0x100,%ecx 3d: 65 gs 3e: 48 rex.W 3f: 8b .byte 0x8b