============================= [ BUG: Invalid wait context ] 6.15.0-syzkaller-11802-g1af80d00e1e0 #0 Not tainted ----------------------------- syz.5.1940/12737 is trying to lock: ffffc9000bd50410 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1819 other info that might help us debug this: context-{2:2} 2 locks held by syz.5.1940/12737: #0: ffff8880244747d8 (&u->iolock){+.+.}-{4:4}, at: __unix_dgram_recvmsg+0x1e2/0xde0 net/unix/af_unix.c:2499 #1: ffffc9000bd50960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #1: ffffc9000bd50960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #1: ffffc9000bd50960 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c3/0x9b0 arch/x86/kvm/xen.c:1817 stack backtrace: CPU: 1 UID: 0 PID: 12737 Comm: syz.5.1940 Not tainted 6.15.0-syzkaller-11802-g1af80d00e1e0 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 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+0xbcb/0xd20 kernel/locking/lockdep.c:5190 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5871 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline] _raw_read_lock_irqsave+0xaf/0x100 kernel/locking/spinlock.c:236 kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1819 xen_timer_callback+0x109/0x220 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x4e0/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194 Code: 74 05 e8 3b ac 60 f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 e3 9a 29 f6 65 8b 05 ac 03 35 07 85 c0 74 40 48 c7 04 24 0e 36 RSP: 0018:ffffc9000402f520 EFLAGS: 00000206 RAX: 1dd32e5a5bc1f300 RBX: 0000000000000a02 RCX: 1dd32e5a5bc1f300 RDX: 0000000000000006 RSI: ffffffff8d979f2e RDI: 0000000000000001 RBP: ffffc9000402f5b8 R08: ffffffff8fa0f5f7 R09: 1ffffffff1f41ebe R10: dffffc0000000000 R11: fffffbfff1f41ebf R12: dffffc0000000000 R13: 1ffff1100488e86d R14: ffff888024474300 R15: 1ffff92000805ea4 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] __skb_try_recv_datagram+0x17c/0x4e0 net/core/datagram.c:267 __unix_dgram_recvmsg+0x2d5/0xde0 net/unix/af_unix.c:2502 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1017 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2784 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2828 do_recvmmsg+0x36a/0x770 net/socket.c:2915 __sys_recvmmsg+0x19d/0x280 net/socket.c:2997 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline] __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline] __ia32_compat_sys_recvmmsg_time32+0xbf/0xe0 net/compat.c:414 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline] __do_fast_syscall_32+0xb6/0x2b0 arch/x86/entry/syscall_32.c:306 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf710e539 Code: 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f50dd55c EFLAGS: 00000206 ORIG_RAX: 0000000000000151 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000800000c0 RDX: 0000000000010106 RSI: 0000000000000002 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 vkms_vblank_simulate: vblank timer overrun ---------------- Code disassembly (best guess): 0: 74 05 je 0x7 2: e8 3b ac 60 f6 call 0xf660ac42 7: 48 c7 44 24 20 00 00 movq $0x0,0x20(%rsp) e: 00 00 10: 9c pushf 11: 8f 44 24 20 pop 0x20(%rsp) 15: f6 44 24 21 02 testb $0x2,0x21(%rsp) 1a: 75 4f jne 0x6b 1c: f7 c3 00 02 00 00 test $0x200,%ebx 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 e3 9a 29 f6 call 0xf6299b12 <-- trapping instruction 2f: 65 8b 05 ac 03 35 07 mov %gs:0x73503ac(%rip),%eax # 0x73503e2 36: 85 c0 test %eax,%eax 38: 74 40 je 0x7a 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss