Commit 4599d78a authored by Kees Cook's avatar Kees Cook Committed by Joerg Roedel
Browse files

iommu/vt-d: Use correctly sized arguments for bit field 



The find.h APIs are designed to be used only on unsigned long arguments.
This can technically result in a over-read, but it is harmless in this
case. Regardless, fix it to avoid the warning seen under -Warray-bounds,
which we'd like to enable globally:

In file included from ./include/linux/bitmap.h:9,
                 from drivers/iommu/intel/iommu.c:17:
drivers/iommu/intel/iommu.c: In function 'domain_context_mapping_one':
./include/linux/find.h:119:37: warning: array subscript 'long unsigned int[0]' is partly outside array bounds of 'int[1]' [-Warray-bounds]
  119 |                 unsigned long val = *addr & GENMASK(size - 1, 0);
      |                                     ^~~~~
drivers/iommu/intel/iommu.c:2115:18: note: while referencing 'max_pde'
 2115 |         int pds, max_pde;
      |                  ^~~~~~~

Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Acked-by: default avatarYury Norov <yury.norov@gmail.com>
Link: https://lore.kernel.org/r/20211215232432.2069605-1-keescook@chromium.org


Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 0fcfb00b

drivers/iommu/intel/iommu.c

+2 −2
Original line number Diff line number Diff line
@@ -2112,10 +2112,10 @@ static void domain_exit(struct dmar_domain *domain) 
 */

static inline unsigned long context_get_sm_pds(struct pasid_table *table)

{

	int pds, max_pde;

	unsigned long pds, max_pde;



	max_pde = table->max_pasid >> PASID_PDE_SHIFT;

	pds = find_first_bit((unsigned long *)&max_pde, MAX_NR_PASID_BITS);

	pds = find_first_bit(&max_pde, MAX_NR_PASID_BITS);

	if (pds < 7)

		return 0;