lkml.org 
[lkml]   [2021]   [Oct]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [PATCH] KVM: x86: Account for 32-bit kernels when handling address in TSC attrs
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>

\
 
 \ /
  Last update: 2021-10-11 16:36    [W:0.050 / U:1.276 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site