Messages in this thread | | | From | Oliver Upton <> | Date | Mon, 11 Oct 2021 09:35:11 -0500 | Subject | Re: [PATCH] KVM: x86: Account for 32-bit kernels when handling address in TSC attrs |
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On Thu, Oct 7, 2021 at 6:16 PM Sean Christopherson <seanjc@google.com> wrote: > > When handling TSC attributes, cast the userspace provided virtual address > to an unsigned long before casting it to a pointer to fix warnings on > 32-bit kernels due to casting a 64-bit integer to a 32-bit pointer. > > Add a check that the truncated address matches the original address, e.g. > to prevent userspace specifying garbage in bits 63:32. > > arch/x86/kvm/x86.c: In function ‘kvm_arch_tsc_get_attr’: > arch/x86/kvm/x86.c:4947:22: error: cast to pointer from integer of different size > 4947 | u64 __user *uaddr = (u64 __user *)attr->addr; > | ^ > arch/x86/kvm/x86.c: In function ‘kvm_arch_tsc_set_attr’: > arch/x86/kvm/x86.c:4967:22: error: cast to pointer from integer of different size > 4967 | u64 __user *uaddr = (u64 __user *)attr->addr; > | ^ > > Cc: Oliver Upton <oupton@google.com> > Fixes: 469fde25e680 ("KVM: x86: Expose TSC offset controls to userspace") > Signed-off-by: Sean Christopherson <seanjc@google.com> > --- > arch/x86/kvm/x86.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) >
Reviewed-by: Oliver Upton <oupton@google.com>
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