============================= [ BUG: Invalid wait context ] syzkaller #0 Not tainted ----------------------------- syz.0.1119/9813 is trying to lock: ffff8880647a9430 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x254/0xeb0 arch/x86/kvm/xen.c:1820 other info that might help us debug this: context-{2:2} 2 locks held by syz.0.1119/9813: #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:867 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: class_rcu_constructor include/linux/rcupdate.h:1195 [inline] #0: ffffffff8e3c4720 (rcu_read_lock){....}-{1:3}, at: unwind_next_frame+0xbd/0x20a0 arch/x86/kernel/unwind_orc.c:479 #1: ffff8880647a9980 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffff8880647a9980 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffff8880647a9980 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x23a/0xeb0 arch/x86/kvm/xen.c:1818 stack backtrace: CPU: 2 UID: 0 PID: 9813 Comm: syz.0.1119 Not tainted syzkaller #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:4830 [inline] check_wait_context kernel/locking/lockdep.c:4902 [inline] __lock_acquire+0xa12/0x1c90 kernel/locking/lockdep.c:5187 lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x350 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+0x254/0xeb0 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+0x5ed/0xad0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:unwind_next_frame+0x67c/0x20a0 arch/x86/kernel/unwind_orc.c:581 Code: 38 c2 40 0f 9e c6 84 d2 0f 95 c0 40 84 c6 0f 85 8a 16 00 00 4c 0f bf 31 4d 01 fe 0f b6 41 05 83 e0 07 3c 03 0f 84 9c 05 00 00 <3c> 04 0f 84 d5 04 00 00 3c 02 0f 84 4e 06 00 00 80 3d 3c 80 fe 0e RSP: 0018:ffffc900042bf400 EFLAGS: 00000297 RAX: 0000000000000002 RBX: 0000000000000001 RCX: ffffffff91c912c2 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001 RBP: ffffc900042bf4b8 R08: ffffffff91c912c6 R09: 0000000000000000 R10: 0000000000000000 R11: 00000000000a6021 R12: ffffc900042bf4c0 R13: ffffc900042bf470 R14: ffffc900042bff48 R15: ffffc900042bff38 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x160/0x1f0 mm/page_owner.c:156 __set_page_owner+0x91/0x560 mm/page_owner.c:332 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850 prep_new_page mm/page_alloc.c:1858 [inline] get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416 alloc_slab_page mm/slub.c:3055 [inline] allocate_slab mm/slub.c:3228 [inline] new_slab+0x24a/0x360 mm/slub.c:3282 ___slab_alloc+0xd79/0x1a50 mm/slub.c:4651 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4774 __slab_alloc_node mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:5272 [inline] kmem_cache_alloc_lru_noprof+0x443/0x6e0 mm/slub.c:5303 sock_alloc_inode+0x25/0x1c0 net/socket.c:322 alloc_inode+0x64/0x240 fs/inode.c:346 new_inode_pseudo include/linux/fs.h:3395 [inline] sock_alloc+0x40/0x280 net/socket.c:637 __sock_create+0xc1/0x8d0 net/socket.c:1569 sock_create net/socket.c:1663 [inline] __sys_socket_create net/socket.c:1700 [inline] __sys_socket+0x14d/0x260 net/socket.c:1747 __do_sys_socket net/socket.c:1761 [inline] __se_sys_socket net/socket.c:1759 [inline] __x64_sys_socket+0x72/0xb0 net/socket.c:1759 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f589298f6c9 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f5893897038 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 00007f5892be5fa0 RCX: 00007f589298f6c9 RDX: 0000000000000010 RSI: 0000000000000003 RDI: 0000000000000010 RBP: 00007f5892a11f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5892be6038 R14: 00007f5892be5fa0 R15: 00007fff25db4648 ---------------- Code disassembly (best guess): 0: 38 c2 cmp %al,%dl 2: 40 0f 9e c6 setle %sil 6: 84 d2 test %dl,%dl 8: 0f 95 c0 setne %al b: 40 84 c6 test %al,%sil e: 0f 85 8a 16 00 00 jne 0x169e 14: 4c 0f bf 31 movswq (%rcx),%r14 18: 4d 01 fe add %r15,%r14 1b: 0f b6 41 05 movzbl 0x5(%rcx),%eax 1f: 83 e0 07 and $0x7,%eax 22: 3c 03 cmp $0x3,%al 24: 0f 84 9c 05 00 00 je 0x5c6 * 2a: 3c 04 cmp $0x4,%al <-- trapping instruction 2c: 0f 84 d5 04 00 00 je 0x507 32: 3c 02 cmp $0x2,%al 34: 0f 84 4e 06 00 00 je 0x688 3a: 80 .byte 0x80 3b: 3d 3c 80 fe 0e cmp $0xefe803c,%eax