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authorMatthew Wilcox (Oracle) <willy@infradead.org>2021-10-04 14:45:56 +0100
committerVlastimil Babka <vbabka@suse.cz>2022-01-06 12:25:51 +0100
commit0b3eb091d5759479d44cb793fad2c51ea06bdcec (patch)
tree00a317cba0a53dc099678ebb16dcec3a4be41539 /mm/slub.c
parent7213230af5e1e83ff010b3448260b9d3f95dd036 (diff)
mm: Convert check_heap_object() to use struct slab
Ensure that we're not seeing a tail page inside __check_heap_object() by converting to a slab instead of a page. Take the opportunity to mark the slab as const since we're not modifying it. Also move the declaration of __check_heap_object() to mm/slab.h so it's not available to the wider kernel. [ vbabka@suse.cz: in check_heap_object() only convert to struct slab for actual PageSlab pages; use folio as intermediate step instead of page ] Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Roman Gushchin <guro@fb.com>
Diffstat (limited to 'mm/slub.c')
-rw-r--r--mm/slub.c10
1 files changed, 5 insertions, 5 deletions
diff --git a/mm/slub.c b/mm/slub.c
index 8e9667815f81..8b82188849ae 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4485,8 +4485,8 @@ EXPORT_SYMBOL(__kmalloc_node);
* Returns NULL if check passes, otherwise const char * to name of cache
* to indicate an error.
*/
-void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
- bool to_user)
+void __check_heap_object(const void *ptr, unsigned long n,
+ const struct slab *slab, bool to_user)
{
struct kmem_cache *s;
unsigned int offset;
@@ -4495,10 +4495,10 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
ptr = kasan_reset_tag(ptr);
/* Find object and usable object size. */
- s = page->slab_cache;
+ s = slab->slab_cache;
/* Reject impossible pointers. */
- if (ptr < page_address(page))
+ if (ptr < slab_address(slab))
usercopy_abort("SLUB object not in SLUB page?!", NULL,
to_user, 0, n);
@@ -4506,7 +4506,7 @@ void __check_heap_object(const void *ptr, unsigned long n, struct page *page,
if (is_kfence)
offset = ptr - kfence_object_start(ptr);
else
- offset = (ptr - page_address(page)) % s->size;
+ offset = (ptr - slab_address(slab)) % s->size;
/* Adjust for redzone and reject if within the redzone. */
if (!is_kfence && kmem_cache_debug_flags(s, SLAB_RED_ZONE)) {