Commit b56c53f3 authored by Vincenzo Frascino's avatar Vincenzo Frascino
Browse files

kasan, mm: untag page address in free_reserved_area



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 <akpm@linux-foundation.org>
Signed-off-by: Vincenzo Frascino's avatarVincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: default avatarAndrey Konovalov <andreyknvl@google.com>
---
Change-Id: If12b4944383575b8bbd7d971decbd7f04be6748b
parent 5385359b
......@@ -7603,6 +7603,11 @@ 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);
......
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