=============================
WARNING: suspicious RCU usage
4.13.0-rc4+ #34 Not tainted
-----------------------------
./include/linux/kvm_host.h:481 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
no locks held by syzkaller245055/3455.

stack backtrace:
CPU: 0 PID: 3455 Comm: syzkaller245055 Not tainted 4.13.0-rc4+ #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4532
 kvm_get_bus include/linux/kvm_host.h:479 [inline]
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:720 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3194 [inline]
 kvm_dev_ioctl+0x877/0x1840 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3245
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x446199
RSP: 002b:00007f37441a3dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446199
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000005
RBP: 0000000000000086 R08: 00007f37441a4700 R09: 00007f37441a4700
R10: 00007f37441a4700 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdf7e1b87f R14: 00007f37441a49c0 R15: 0000000000000000

=============================
WARNING: suspicious RCU usage
4.13.0-rc4+ #34 Not tainted
-----------------------------
./include/linux/kvm_host.h:575 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
no locks held by syzkaller245055/3455.

stack backtrace:
CPU: 0 PID: 3455 Comm: syzkaller245055 Not tainted 4.13.0-rc4+ #34
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 lockdep_rcu_suspicious+0x123/0x170 kernel/locking/lockdep.c:4532
 __kvm_memslots include/linux/kvm_host.h:573 [inline]
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:722 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3194 [inline]
 kvm_dev_ioctl+0xd21/0x1840 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3245
 vfs_ioctl fs/ioctl.c:45 [inline]
 do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x446199
RSP: 002b:00007f37441a3dc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446199
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000005
RBP: 0000000000000086 R08: 00007f37441a4700 R09: 00007f37441a4700
R10: 00007f37441a4700 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffdf7e1b87f R14: 00007f37441a49c0 R15: 0000000000000000