============================= [ BUG: Invalid wait context ] syzkaller #0 Not tainted ----------------------------- kworker/u4:10/1081 is trying to lock: ffff888052abd410 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1fb/0x9b0 arch/x86/kvm/xen.c:1820 other info that might help us debug this: context-{2:2} 4 locks held by kworker/u4:10/1081: #0: ffff88803f219948 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3211 [inline] #0: ffff88803f219948 ((wq_completion)bat_events){+.+.}-{0:0}, at: process_scheduled_works+0x9b4/0x17b0 kernel/workqueue.c:3319 #1: ffffc9000265fbc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3212 [inline] #1: ffffc9000265fbc0 ((work_completion)(&(&bat_priv->nc.work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x9ef/0x17b0 kernel/workqueue.c:3319 #2: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] #2: ffffffff8e139f20 (rcu_read_lock){....}-{1:3}, at: batadv_nc_worker+0xd2/0x610 net/batman-adv/network-coding.c:719 #3: ffff888052abd960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline] #3: ffff888052abd960 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline] #3: ffff888052abd960 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1c3/0x9b0 arch/x86/kvm/xen.c:1818 stack backtrace: CPU: 0 UID: 0 PID: 1081 Comm: kworker/u4:10 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 Workqueue: bat_events batadv_nc_worker Call Trace: dump_stack_lvl+0x189/0x250 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+0xbcb/0xd20 kernel/locking/lockdep.c:5187 lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868 __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:1820 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:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 bb d1 03 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000265f980 EFLAGS: 00000206 RAX: f0d7be597535b200 RBX: 0000000000000000 RCX: f0d7be597535b200 RDX: 0000000000000000 RSI: ffffffff8dbaa9c9 RDI: ffffffff8be34a00 RBP: ffffffff8b4945e2 R08: 0000000000000000 R09: ffffffff8b4945e2 R10: dffffc0000000000 R11: ffffffff8b494510 R12: 0000000000000002 R13: ffffffff8e139f20 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xef/0x610 net/batman-adv/network-coding.c:719 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ---------------- Code disassembly (best guess): 0: 00 00 add %al,(%rax) 2: 00 00 add %al,(%rax) 4: 9c pushf 5: 8f 44 24 30 pop 0x30(%rsp) 9: f7 44 24 30 00 02 00 testl $0x200,0x30(%rsp) 10: 00 11: 0f 85 cd 00 00 00 jne 0xe4 17: f7 44 24 08 00 02 00 testl $0x200,0x8(%rsp) 1e: 00 1f: 74 01 je 0x22 21: fb sti 22: 65 48 8b 05 bb d1 03 mov %gs:0x1103d1bb(%rip),%rax # 0x1103d1e5 29: 11 * 2a: 48 3b 44 24 58 cmp 0x58(%rsp),%rax <-- trapping instruction 2f: 0f 85 f2 00 00 00 jne 0x127 35: 48 83 c4 60 add $0x60,%rsp 39: 5b pop %rbx 3a: 41 5c pop %r12 3c: 41 5d pop %r13 3e: 41 5e pop %r14