============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G L ----------------------------- syz.4.1352/10702 is trying to lock: ffff888055b3d2e0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1820 other info that might help us debug this: context-{2:2} 4 locks held by syz.4.1352/10702: #0: ffff88801b883440 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock include/linux/mmap_lock.h:391 [inline] #0: ffff88801b883440 (&mm->mmap_lock){++++}-{4:4}, at: exit_mmap+0x106/0xae0 mm/mmap.c:1262 #1: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #1: ffffffff8e5e32e0 (rcu_read_lock){....}-{1:3}, at: ___pte_offset_map+0x2f/0x310 mm/pgtable-generic.c:288 #2: ffff8880365dcc18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: spin_lock include/linux/spinlock.h:351 [inline] #2: ffff8880365dcc18 (ptlock_ptr(ptdesc)#2){+.+.}-{3:3}, at: __pte_offset_map_lock+0x10f/0x320 mm/pgtable-generic.c:403 #3: ffff888055b3d838 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:185 [inline] #3: ffff888055b3d838 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:277 [inline] #3: ffff888055b3d838 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x245/0xe80 arch/x86/kvm/xen.c:1818 stack backtrace: CPU: 0 UID: 0 PID: 10702 Comm: syz.4.1352 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:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xfa4/0x2630 kernel/locking/lockdep.c:5187 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x17c/0x330 kernel/locking/lockdep.c:5825 __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+0x253/0xe80 arch/x86/kvm/xen.c:1820 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x1ad/0x990 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x109/0x3c0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210 Code: 86 02 59 00 48 89 df 5b e9 0d 76 5e 00 be 03 00 00 00 5b e9 f2 59 e0 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 c5 44 dd 11 48 8b 34 24 65 48 8b 15 a1 44 dd RSP: 0018:ffffc90025d3f568 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffea0000f2bd80 RCX: ffffffff825d4afb RDX: ffff88802ec10000 RSI: ffffffff825d4b13 RDI: ffff88802ec10000 RBP: ffffea0000f2bd80 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff88802eca92c0 R14: ffffea0000f2bd80 R15: 0000000000000000 __folio_rmap_sanity_checks include/linux/rmap.h:417 [inline] __folio_remove_rmap mm/rmap.c:1663 [inline] folio_remove_rmap_ptes+0x1b8/0xff0 mm/rmap.c:1779 zap_present_folio_ptes mm/memory.c:1654 [inline] zap_present_ptes mm/memory.c:1712 [inline] do_zap_pte_range mm/memory.c:1814 [inline] zap_pte_range mm/memory.c:1858 [inline] zap_pmd_range mm/memory.c:1950 [inline] zap_pud_range mm/memory.c:1978 [inline] zap_p4d_range mm/memory.c:1999 [inline] unmap_page_range+0x1c05/0x43e0 mm/memory.c:2020 unmap_single_vma+0x153/0x240 mm/memory.c:2062 unmap_vmas+0x218/0x470 mm/memory.c:2104 exit_mmap+0x181/0xae0 mm/mmap.c:1277 __mmput+0x12a/0x410 kernel/fork.c:1173 mmput+0x67/0x80 kernel/fork.c:1196 exit_mm kernel/exit.c:581 [inline] do_exit+0x78a/0x2a30 kernel/exit.c:959 do_group_exit+0xd5/0x2a0 kernel/exit.c:1112 get_signal+0x1ec7/0x21e0 kernel/signal.c:3034 arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x86/0x4b0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4fe/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb74a19acb9 Code: Unable to access opcode bytes at 0x7fb74a19ac8f. RSP: 002b:00007fb74b07e0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fb74a416188 RCX: 00007fb74a19acb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb74a416188 RBP: 00007fb74a416180 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb74a416218 R14: 00007fff196d9e60 R15: 00007fff196d9f48 ---------------- Code disassembly (best guess): 0: 86 02 xchg %al,(%rdx) 2: 59 pop %rcx 3: 00 48 89 add %cl,-0x77(%rax) 6: df 5b e9 fistps -0x17(%rbx) 9: 0d 76 5e 00 be or $0xbe005e76,%eax e: 03 00 add (%rax),%eax 10: 00 00 add %al,(%rax) 12: 5b pop %rbx 13: e9 f2 59 e0 02 jmp 0x2e05a0a 18: 66 90 xchg %ax,%ax 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 90 nop 1f: 90 nop 20: 90 nop 21: 90 nop 22: 90 nop 23: 90 nop 24: 90 nop 25: 90 nop 26: 90 nop 27: 90 nop 28: 90 nop 29: 90 nop * 2a: f3 0f 1e fa endbr64 <-- trapping instruction 2e: 65 8b 05 c5 44 dd 11 mov %gs:0x11dd44c5(%rip),%eax # 0x11dd44fa 35: 48 8b 34 24 mov (%rsp),%rsi 39: 65 gs 3a: 48 rex.W 3b: 8b .byte 0x8b 3c: 15 .byte 0x15 3d: a1 .byte 0xa1 3e: 44 rex.R 3f: dd .byte 0xdd