KVM: x86: Harden copying of userspace-array against overflow

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cpuid.c utilizes vmemdup_user() and array_size() to copy two userspace
arrays. This, currently, does not check for an overflow.

Use the new wrapper vmemdup_array_user() to copy the arrays more safely,
as vmemdup_user() doesn't check for overflow.

Note, KVM explicitly checks the number of entries before duplicating the
array, i.e. adding the overflow check should be a glorified nop.

Suggested-by: Dave Airlie <airlied@redhat.com>
Signed-off-by: Philipp Stanner <pstanner@redhat.com>
Link: https://lore.kernel.org/r/20231102181526.43279-2-pstanner@redhat.com
[sean: call out that KVM pre-checks the number of entries]
Signed-off-by: Sean Christopherson <seanjc@google.com>

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Philipp Stanner 2023-11-02 19:15:24 +01:00 • committed by Sean Christopherson

parent 63912245c1

commit 573cc0e5cf

1 changed files with 2 additions and 2 deletions

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arch/x86/kvm/cpuid.c

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