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https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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Sean ChristophersonandGreg Kroah-Hartman
570af5db08
commit 7ef78d71ca upstream.
When updating CR8 intercepts, get vmcs12 if and only if the vCPU is in
guest mode so that a future change can have update CR8 intercepts during
vCPU creation, without running afoul of get_vmcs12()'s lockdep assertion.
------------[ cut here ]------------
debug_locks && !(lock_is_held(&(&vcpu->mutex)->dep_map) || !refcount_read(&vcpu->kvm->users_count))
WARNING: arch/x86/kvm/vmx/nested.h:61 at get_vmcs12 arch/x86/kvm/vmx/nested.h:60 [inline], CPU#0: syz.2.19/5879
WARNING: arch/x86/kvm/vmx/nested.h:61 at vmx_update_cr8_intercept+0x3de/0x4e0 arch/x86/kvm/vmx/vmx.c:6879, CPU#0: syz.2.19/5879
Modules linked in:
CPU: 0 UID: 0 PID: 5879 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:get_vmcs12 arch/x86/kvm/vmx/nested.h:60 [inline]
RIP: 0010:vmx_update_cr8_intercept+0x3de/0x4e0 arch/x86/kvm/vmx/vmx.c:6879
Call Trace:
<TASK>
apic_update_ppr arch/x86/kvm/lapic.c:984 [inline]
kvm_lapic_reset+0x1c24/0x2980 arch/x86/kvm/lapic.c:3023
kvm_vcpu_reset+0x44c/0x1bf0 arch/x86/kvm/x86.c:12986
kvm_arch_vcpu_create+0x746/0x8b0 arch/x86/kvm/x86.c:12847
kvm_vm_ioctl_create_vcpu+0x428/0x930 virt/kvm/kvm_main.c:4201
kvm_vm_ioctl+0x893/0xd50 virt/kvm/kvm_main.c:5159
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
</TASK>
No functional change intended.
Reported-by: syzbot ci <syzbot+ci493c6d734b63e050@syzkaller.appspotmail.com>
Closes: https://lore.kernel.org/all/6a2adf3b.3b0a2d4e.8c8d1.0012.GAE@google.com
Cc: stable@vger.kernel.org
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260618174347.1981064-2-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>