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authorOtavio Salvador <otavio@ossystems.com.br>2020-05-20 08:43:03 -0300
committerGitHub <noreply@github.com>2020-05-20 08:43:03 -0300
commit1279cd128bba968ebe0a2df7f7ae38bae90250ef (patch)
treedf6b1a190760f51465122ca4c13492d5ac5984c6 /mm/usercopy.c
parent0a8ab17689e628c84a666195bfc6ab85d11cf057 (diff)
parent2ae782ca839e0ee07de37122ddea362adff2e975 (diff)
Merge pull request #76 from toradex/4.9-2.3.x-imx
4.9 2.3.x imx
Diffstat (limited to 'mm/usercopy.c')
-rw-r--r--mm/usercopy.c10
1 files changed, 8 insertions, 2 deletions
diff --git a/mm/usercopy.c b/mm/usercopy.c
index 3c8da0af9695..c2de343baad4 100644
--- a/mm/usercopy.c
+++ b/mm/usercopy.c
@@ -15,6 +15,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/mm.h>
+#include <linux/highmem.h>
#include <linux/slab.h>
#include <asm/sections.h>
@@ -124,7 +125,7 @@ static inline const char *check_kernel_text_object(const void *ptr,
static inline const char *check_bogus_address(const void *ptr, unsigned long n)
{
/* Reject if object wraps past end of memory. */
- if ((unsigned long)ptr + n < (unsigned long)ptr)
+ if ((unsigned long)ptr + (n - 1) < (unsigned long)ptr)
return "<wrapped address>";
/* Reject if NULL or ZERO-allocation. */
@@ -217,7 +218,12 @@ static inline const char *check_heap_object(const void *ptr, unsigned long n,
if (!virt_addr_valid(ptr))
return NULL;
- page = virt_to_head_page(ptr);
+ /*
+ * When CONFIG_HIGHMEM=y, kmap_to_page() will give either the
+ * highmem page or fallback to virt_to_page(). The following
+ * is effectively a highmem-aware virt_to_head_page().
+ */
+ page = compound_head(kmap_to_page((void *)ptr));
/* Check slab allocator for flags and size. */
if (PageSlab(page))