remarkable-linux/arch
Wanpeng Li 2f707d9798 KVM: nVMX: reset nested_run_pending if the vCPU is going to be reset
Reported by syzkaller:

    WARNING: CPU: 1 PID: 27742 at arch/x86/kvm/vmx.c:11029
    nested_vmx_vmexit+0x5c35/0x74d0 arch/x86/kvm/vmx.c:11029
    CPU: 1 PID: 27742 Comm: a.out Not tainted 4.10.0+ #229
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     __dump_stack lib/dump_stack.c:15 [inline]
     dump_stack+0x2ee/0x3ef lib/dump_stack.c:51
     panic+0x1fb/0x412 kernel/panic.c:179
     __warn+0x1c4/0x1e0 kernel/panic.c:540
     warn_slowpath_null+0x2c/0x40 kernel/panic.c:583
     nested_vmx_vmexit+0x5c35/0x74d0 arch/x86/kvm/vmx.c:11029
     vmx_leave_nested arch/x86/kvm/vmx.c:11136 [inline]
     vmx_set_msr+0x1565/0x1910 arch/x86/kvm/vmx.c:3324
     kvm_set_msr+0xd4/0x170 arch/x86/kvm/x86.c:1099
     do_set_msr+0x11e/0x190 arch/x86/kvm/x86.c:1128
     __msr_io arch/x86/kvm/x86.c:2577 [inline]
     msr_io+0x24b/0x450 arch/x86/kvm/x86.c:2614
     kvm_arch_vcpu_ioctl+0x35b/0x46a0 arch/x86/kvm/x86.c:3497
     kvm_vcpu_ioctl+0x232/0x1120 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2721
     vfs_ioctl fs/ioctl.c:43 [inline]
     do_vfs_ioctl+0x1bf/0x1790 fs/ioctl.c:683
     SYSC_ioctl fs/ioctl.c:698 [inline]
     SyS_ioctl+0x8f/0xc0 fs/ioctl.c:689
     entry_SYSCALL_64_fastpath+0x1f/0xc2

The syzkaller folks reported a nested_run_pending warning during userspace
clear VMX capability which is exposed to L1 before.

The warning gets thrown while doing

(*(uint32_t*)0x20aecfe8 = (uint32_t)0x1);
(*(uint32_t*)0x20aecfec = (uint32_t)0x0);
(*(uint32_t*)0x20aecff0 = (uint32_t)0x3a);
(*(uint32_t*)0x20aecff4 = (uint32_t)0x0);
(*(uint64_t*)0x20aecff8 = (uint64_t)0x0);
r[29] = syscall(__NR_ioctl, r[4], 0x4008ae89ul,
		0x20aecfe8ul, 0, 0, 0, 0, 0, 0);

i.e. KVM_SET_MSR ioctl with

struct kvm_msrs {
	.nmsrs = 1,
		.pad = 0,
		.entries = {
			{.index = MSR_IA32_FEATURE_CONTROL,
			 .reserved = 0,
			 .data = 0}
		}
}

The VMLANCH/VMRESUME emulation should be stopped since the CPU is going to
reset here. This patch resets the nested_run_pending since the CPU is going
to be reset hence there should be nothing pending.

Reported-by: Dmitry Vyukov <dvyukov@google.com>
Suggested-by: Radim Krčmář <rkrcmar@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Jim Mattson <jmattson@google.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
2017-03-07 15:41:12 +01:00
..
alpha sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
arc sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
arm Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2017-03-04 10:42:53 -08:00
arm64 ARM: SoC: late DT updates for v4.11 2017-03-03 16:15:48 -08:00
avr32 sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
blackfin sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
c6x sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
cris sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
frv sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
h8300 sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
hexagon sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
ia64 sched/core: Remove unused prefetch_stack() 2017-03-03 01:45:38 +01:00
m32r sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
m68k sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
metag sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
microblaze sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
mips sched/headers: Remove the <linux/topology.h> include from <linux/sched.h> 2017-03-03 01:45:41 +01:00
mn10300 sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h> 2017-03-02 08:42:37 +01:00
nios2 sched/headers: Prepare to move 'init_task' and 'init_thread_union' from <linux/sched.h> to <linux/sched/task.h> 2017-03-02 08:42:38 +01:00
openrisc sched/headers: Prepare to move kstack_end() from <linux/sched.h> to <linux/sched/task_stack.h> 2017-03-02 08:42:39 +01:00
parisc Merge branch 'parisc-4.11-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2017-03-03 16:20:06 -08:00
powerpc Second batch of KVM changes for 4.11 merge window 2017-03-04 11:36:19 -08:00
s390 sched/headers: Move task statistics APIs from <linux/sched.h> to <linux/sched/stat.h> 2017-03-03 01:43:43 +01:00
score sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
sh sched/headers: Remove <asm/ptrace.h> from <linux/sched.h> 2017-03-03 01:45:33 +01:00
sparc sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
tile sched/headers: Move task->mm handling methods to <linux/sched/mm.h> 2017-03-03 01:43:28 +01:00
um sched/headers: Prepare to move kstack_end() from <linux/sched.h> to <linux/sched/task_stack.h> 2017-03-02 08:42:39 +01:00
unicore32 sched/headers: Prepare for new header dependencies before moving code to <linux/sched/task_stack.h> 2017-03-02 08:42:36 +01:00
x86 KVM: nVMX: reset nested_run_pending if the vCPU is going to be reset 2017-03-07 15:41:12 +01:00
xtensa Xtensa improvements for v4.11: 2017-03-03 16:17:55 -08:00
.gitignore
Kconfig scripts/spelling.txt: add "an user" pattern and fix typo instances 2017-02-27 18:43:46 -08:00