============================= [ BUG: Invalid wait context ] syzkaller #0 Tainted: G L ----------------------------- syz.6.623/8215 is trying to lock: ffff8880556612e0 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1819 other info that might help us debug this: context-{2:2} 2 locks held by syz.6.623/8215: #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock_dont_migrate include/linux/rcupdate.h:992 [inline] #0: ffffffff8e7e7920 (rcu_read_lock){....}-{1:3}, at: bpf_test_timer_enter+0xc3/0x2b0 net/bpf/test_run.c:39 #1: ffff888055661840 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:187 [inline] #1: ffff888055661840 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:294 [inline] #1: ffff888055661840 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x245/0xe80 arch/x86/kvm/xen.c:1817 stack backtrace: CPU: 2 UID: 0 PID: 8215 Comm: syz.6.623 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+0x1cf/0x380 kernel/locking/lockdep.c:5825 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:172 [inline] _raw_read_lock_irqsave+0x46/0x90 kernel/locking/spinlock.c:236 kvm_xen_set_evtchn_fast+0x253/0xe80 arch/x86/kvm/xen.c:1819 xen_timer_callback+0x1db/0x2a0 arch/x86/kvm/xen.c:140 __run_hrtimer kernel/time/hrtimer.c:1785 [inline] __hrtimer_run_queues+0x1ad/0xa70 kernel/time/hrtimer.c:1849 hrtimer_interrupt+0x397/0x8c0 kernel/time/hrtimer.c:1911 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x109/0x490 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:get_current arch/x86/include/asm/current.h:23 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xf/0x70 kernel/kcov.c:216 Code: 00 00 00 5b e9 a2 1b ee 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 65 8b 05 05 83 05 12 48 8b 34 24 <65> 48 8b 15 e1 82 05 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 RSP: 0018:ffffc9000349f848 EFLAGS: 00000246 RAX: 0000000080000200 RBX: 0000000000000102 RCX: ffffc90026ad9000 RDX: 0000000000080000 RSI: ffffffff89a4d5d8 RDI: ffff8880277e0808 RBP: ffff88805bc424c0 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000080 R11: ffff88801decfc00 R12: 1ffff92000693f19 R13: ffffc90005fb9000 R14: ffffc9000349f998 R15: dffffc0000000000 local_bh_enable include/linux/bottom_half.h:33 [inline] bpf_test_run+0x298/0xa40 net/bpf/test_run.c:426 bpf_prog_test_run_skb+0x107b/0x3230 net/bpf/test_run.c:1159 bpf_prog_test_run kernel/bpf/syscall.c:4743 [inline] __sys_bpf+0x1725/0x4b90 kernel/bpf/syscall.c:6267 __do_sys_bpf kernel/bpf/syscall.c:6362 [inline] __se_sys_bpf kernel/bpf/syscall.c:6360 [inline] __x64_sys_bpf+0x7b/0xc0 kernel/bpf/syscall.c:6360 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fd314d9c819 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:00007fd315ce2028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007fd315016180 RCX: 00007fd314d9c819 RDX: 0000000000000050 RSI: 0000200000000140 RDI: 000000000000000a RBP: 00007fd314e32c91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fd315016218 R14: 00007fd315016180 R15: 00007ffe1bc1baf8 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 5b e9 add %bl,-0x17(%rbx) 5: a2 1b ee 02 66 90 90 movabs %al,0x909090906602ee1b c: 90 90 e: 90 nop 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: f3 0f 1e fa endbr64 1f: 65 8b 05 05 83 05 12 mov %gs:0x12058305(%rip),%eax # 0x1205832b 26: 48 8b 34 24 mov (%rsp),%rsi * 2a: 65 48 8b 15 e1 82 05 mov %gs:0x120582e1(%rip),%rdx # 0x12058313 <-- trapping instruction 31: 12 32: a9 00 01 ff 00 test $0xff0100,%eax 37: 74 1b je 0x54 39: f6 c4 01 test $0x1,%ah 3c: 74 07 je 0x45 3e: a9 .byte 0xa9