============================= [ BUG: Invalid wait context ] 6.15.0-syzkaller-08297-ge0797d3b91de #0 Not tainted ----------------------------- swapper/0/0 is trying to lock: ffffc90005db2410 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x254/0xeb0 arch/x86/kvm/xen.c:1819 other info that might help us debug this: context-{2:2} 2 locks held by swapper/0/0: #0: ffffffff8e3c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c47c0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8e3c47c0 (rcu_read_lock){....}-{1:3}, at: sched_balance_domains+0x115/0xee0 kernel/sched/fair.c:12204 #1: ffffc90005db2960 (&kvm->srcu){.?.?}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffffc90005db2960 (&kvm->srcu){.?.?}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffffc90005db2960 (&kvm->srcu){.?.?}-{0:0}, at: kvm_xen_set_evtchn_fast+0x23a/0xeb0 arch/x86/kvm/xen.c:1817 stack backtrace: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.15.0-syzkaller-08297-ge0797d3b91de #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4833 [inline] check_wait_context kernel/locking/lockdep.c:4905 [inline] __lock_acquire+0xa12/0x1c90 kernel/locking/lockdep.c:5190 lock_acquire kernel/locking/lockdep.c:5871 [inline] lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5828 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:236 kvm_xen_set_evtchn_fast+0x254/0xeb0 arch/x86/kvm/xen.c:1819 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x5ed/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0x52/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:update_sd_pick_busiest kernel/sched/fair.c:10583 [inline] RIP: 0010:update_sd_lb_stats.constprop.0+0x1bc1/0x2d70 kernel/sched/fair.c:11054 Code: ba 00 00 00 00 00 fc ff df 48 89 f9 48 c1 e9 03 80 3c 11 00 0f 85 8d 0b 00 00 4d 3b 67 30 0f 82 59 ee ff ff 0f 84 5a 03 00 00 <83> f8 01 0f 87 22 f4 ff ff 45 84 d2 0f 84 19 f4 ff ff 48 b8 00 00 RSP: 0018:ffffc90000007870 EFLAGS: 00000286 RAX: 0000000000000000 RBX: ffff88801e2eec80 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 1ffff92000000f5f RDI: ffffc90000007af8 RBP: dffffc0000000000 R08: ffffc900000079b0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffc90000007988 R14: ffffc90000007998 R15: ffffc90000007a98 sched_balance_find_src_group+0x92/0xc90 kernel/sched/fair.c:11311 sched_balance_rq+0x851/0x3110 kernel/sched/fair.c:11773 sched_balance_domains+0x6ff/0xee0 kernel/sched/fair.c:12233 handle_softirqs+0x219/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 93 55 02 e9 53 fb 02 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d f3 50 0e 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffffff8e007e08 EFLAGS: 00000286 RAX: 000000000016d021 RBX: 0000000000000000 RCX: ffffffff8b7bb449 RDX: 0000000000000000 RSI: ffffffff8dc0590b RDI: ffffffff8bf52e80 RBP: fffffbfff1c12ee8 R08: 0000000000000001 R09: ffffed100d48663d R10: ffff88806a4331eb R11: 0000000000000001 R12: 0000000000000000 R13: ffffffff8e097740 R14: ffffffff90878750 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:743 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 rest_init+0x16b/0x2b0 init/main.c:743 start_kernel+0x3e9/0x4d0 init/main.c:1099 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x148 IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available IPVS: lc: UDP 224.0.0.2:0 - no destination available ---------------- Code disassembly (best guess): 0: ba 00 00 00 00 mov $0x0,%edx 5: 00 fc add %bh,%ah 7: ff (bad) 8: df 48 89 fisttps -0x77(%rax) b: f9 stc c: 48 c1 e9 03 shr $0x3,%rcx 10: 80 3c 11 00 cmpb $0x0,(%rcx,%rdx,1) 14: 0f 85 8d 0b 00 00 jne 0xba7 1a: 4d 3b 67 30 cmp 0x30(%r15),%r12 1e: 0f 82 59 ee ff ff jb 0xffffee7d 24: 0f 84 5a 03 00 00 je 0x384 * 2a: 83 f8 01 cmp $0x1,%eax <-- trapping instruction 2d: 0f 87 22 f4 ff ff ja 0xfffff455 33: 45 84 d2 test %r10b,%r10b 36: 0f 84 19 f4 ff ff je 0xfffff455 3c: 48 rex.W 3d: b8 .byte 0xb8