xen/privcmd: fix error handling in mmap-resource processing

xen_pfn_t is the same size as int only on 32-bit builds (and not even
on Arm32). Hence pfns[] can't be used directly to read individual error
values returned from xen_remap_domain_mfn_array(); every other error
indicator would be skipped/ignored on 64-bit.

Fixes: 3ad0876554 ("xen/privcmd: add IOCTL_PRIVCMD_MMAP_RESOURCE")
Cc: stable@vger.kernel.org
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>

Link: https://lore.kernel.org/r/aa6d6a67-6889-338a-a910-51e889f792d5@suse.com
Signed-off-by: Juergen Gross <jgross@suse.com>
This commit is contained in:
Jan Beulich 2021-09-22 12:17:48 +02:00 committed by Juergen Gross
parent 0432523f48
commit e11423d672

View File

@ -803,11 +803,12 @@ static long privcmd_ioctl_mmap_resource(struct file *file,
unsigned int domid =
(xdata.flags & XENMEM_rsrc_acq_caller_owned) ?
DOMID_SELF : kdata.dom;
int num;
int num, *errs = (int *)pfns;
BUILD_BUG_ON(sizeof(*errs) > sizeof(*pfns));
num = xen_remap_domain_mfn_array(vma,
kdata.addr & PAGE_MASK,
pfns, kdata.num, (int *)pfns,
pfns, kdata.num, errs,
vma->vm_page_prot,
domid,
vma->vm_private_data);
@ -817,7 +818,7 @@ static long privcmd_ioctl_mmap_resource(struct file *file,
unsigned int i;
for (i = 0; i < num; i++) {
rc = pfns[i];
rc = errs[i];
if (rc < 0)
break;
}