[PATCH 4.19 STABLE v2 0/2] KVM: VMX: Fix null pointer dereference

From: Sean Christopherson
Date: Mon May 11 2020 - 20:28:25 EST


A simple fix for a null pointer dereference in vmx_vcpu_run() with an
ugly-but-safe prereq patch.

The even uglier ASM_CALL_CONSTRAINT is gone in v2 as I finally figured
out why vmx_return was undefined: GCC dropped the entire asm blob because
all outputs were deemed unused.

v2:
- Document why there is no exact upstream commit for the fix, with
--verbose. [Greg]
- Tag the asm blob as volatile and drop the ASM_CALL_CONSTRAINT hack.

Sean Christopherson (2):
KVM: VMX: Explicitly reference RCX as the vmx_vcpu pointer in asm
blobs
KVM: VMX: Mark RCX, RDX and RSI as clobbered in vmx_vcpu_run()'s asm
blob

arch/x86/kvm/vmx.c | 91 +++++++++++++++++++++++++---------------------
1 file changed, 50 insertions(+), 41 deletions(-)

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2.26.0