From: Vincenzo Frascino <vincenzo.frasc...@arm.com>
free_reserved_area() memsets the pages belonging to a given memory area.
As that memory hasn't been allocated via page_alloc, the KASAN tags that
those pages have are 0x00. As the result the memset might result in a tag
mismatch.
Untag the address to avoid spurious faults.
Cc: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frasc...@arm.com>
Signed-off-by: Andrey Konovalov <andreyk...@google.com>
Reviewed-by: Alexander Potapenko <gli...@google.com>
---
Change-Id: If12b4944383575b8bbd7d971decbd7f04be6748b
---
mm/page_alloc.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 42c32e8a9c5d..236aa4b6b2cc 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -7659,6 +7659,11 @@ unsigned long free_reserved_area(void *start, void *end,
int poison, const char
* alias for the memset().
*/
direct_map_addr = page_address(page);
+ /*
+ * Perform a kasan-unchecked memset() since this memory
+ * has not been initialized.
+ */
+ direct_map_addr = kasan_reset_tag(direct_map_addr);
if ((unsigned int)poison <= 0xFF)
memset(direct_map_addr, poison, PAGE_SIZE);
--
2.29.2.454.gaff20da3a2-goog
