============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G L ----------------------------- syz.4.2890/16559 is trying to lock: ffff88802ca7dbb0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1822 other info that might help us debug this: context-{2:2} locks held by syz.4.2890/16559: 3, last CPU#2: #0: ffff8880276fd038 (&mm->mmap_lock){++++}-{4:4}, at: mmap_write_lock include/linux/mmap_lock.h:544 [inline] #0: ffff8880276fd038 (&mm->mmap_lock){++++}-{4:4}, at: mmu_notifier_register+0x37/0x1c0 mm/mmu_notifier.c:750 #1: ffffffff8efc2e00 (mm_all_locks_mutex){+.+.}-{4:4}, at: mm_take_all_locks+0x103/0xb70 mm/vma.c:2286 #2: ffff88802ca7e110 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #2: ffff88802ca7e110 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #2: ffff88802ca7e110 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x245/0xe80 arch/x86/kvm/xen.c:1820 stack backtrace: CPU: 2 UID: 0 PID: 16559 Comm: syz.4.2890 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_lock_invalid_wait_context kernel/locking/lockdep.c:4846 [inline] check_wait_context kernel/locking/lockdep.c:4918 [inline] __lock_acquire+0x104c/0x1ec0 kernel/locking/lockdep.c:5203 lock_acquire kernel/locking/lockdep.c:5886 [inline] lock_acquire+0x1b9/0x370 kernel/locking/lockdep.c:5843 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:174 [inline] _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:271 kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1822 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:2067 [inline] __hrtimer_run_queues+0x13f/0x9c0 kernel/time/hrtimer.c:2124 hrtimer_interrupt+0x441/0xaa0 kernel/time/hrtimer.c:2243 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_is_held_type+0xa/0x140 kernel/locking/lockdep.c:5952 Code: c6 6f dd 3a 8e 67 48 0f b9 3a eb c7 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 8b 0d 6a ab 7c 05 ff ff ff ff 85 c9 0f 84 ed 00 00 00 65 8b 15 aa 47 c1 08 85 d2 RSP: 0018:ffffc90004067ab0 EFLAGS: 00000283 RAX: 0000000000002051 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000080000 RSI: 00000000ffffffff RDI: ffff8880276fd038 RBP: ffff8880276fd038 R08: 0000000000000005 R09: 0000000000000300 R10: 0000000000000300 R11: 0000000000000000 R12: ffff8880276fccc0 R13: dffffc0000000000 R14: 0000000000000000 R15: 000000110c22ffff lock_is_held include/linux/lockdep.h:249 [inline] mt_locked lib/maple_tree.c:708 [inline] mt_slot lib/maple_tree.c:715 [inline] mtree_range_walk+0x30b/0xb70 lib/maple_tree.c:2050 mas_state_walk lib/maple_tree.c:2952 [inline] mas_walk+0x533/0x9b0 lib/maple_tree.c:4366 mas_find_setup lib/maple_tree.c:5345 [inline] mas_find+0x4e6/0x740 lib/maple_tree.c:5385 vma_next include/linux/mm.h:1676 [inline] mm_take_all_locks+0x133/0xb70 mm/vma.c:2294 __mmu_notifier_register+0x5b3/0x780 mm/mmu_notifier.c:680 mmu_notifier_register+0x74/0x1c0 mm/mmu_notifier.c:751 kvm_init_mmu_notifier virt/kvm/kvm_main.c:890 [inline] kvm_create_vm virt/kvm/kvm_main.c:1188 [inline] kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:5493 [inline] kvm_dev_ioctl+0xe9f/0x1b50 virt/kvm/kvm_main.c:5535 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f064ab9e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f064b9e1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f064ae25fa0 RCX: 00007f064ab9e0d9 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000004 RBP: 00007f064ac35024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f064ae26038 R14: 00007f064ae25fa0 R15: 00007fff2b373188 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: 6f outsl %ds:(%rsi),(%dx) 1: dd 3a fnstsw (%rdx) 3: 8e 67 48 mov 0x48(%rdi),%fs 6: 0f b9 3a ud1 (%rdx),%edi 9: eb c7 jmp 0xffffffd2 b: 0f 1f 40 00 nopl 0x0(%rax) f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: f3 0f 1e fa endbr64 23: 8b 0d 6a ab 7c 05 mov 0x57cab6a(%rip),%ecx # 0x57cab93 * 29: b8 ff ff ff ff mov $0xffffffff,%eax <-- trapping instruction 2e: 85 c9 test %ecx,%ecx 30: 0f 84 ed 00 00 00 je 0x123 36: 65 8b 15 aa 47 c1 08 mov %gs:0x8c147aa(%rip),%edx # 0x8c147e7 3d: 85 d2 test %edx,%edx