[PATCH v3 2/2] kasan, slub: reset tag when printing address

Kuan-Ying Lee Kuan-Ying.Lee at mediatek.com
Wed Aug 4 02:09:57 PDT 2021


The address still includes the tags when it is printed.
With hardware tag-based kasan enabled, we will get a
false positive KASAN issue when we access metadata.

Reset the tag before we access the metadata.

Fixes: aa1ef4d7b3f6 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Kuan-Ying Lee <Kuan-Ying.Lee at mediatek.com>
Reviewed-by: Marco Elver <elver at google.com>
---
 mm/slub.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/slub.c b/mm/slub.c
index b6c5205252eb..f77d8cd79ef7 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -576,8 +576,8 @@ static void print_section(char *level, char *text, u8 *addr,
 			  unsigned int length)
 {
 	metadata_access_enable();
-	print_hex_dump(level, kasan_reset_tag(text), DUMP_PREFIX_ADDRESS,
-			16, 1, addr, length, 1);
+	print_hex_dump(level, text, DUMP_PREFIX_ADDRESS,
+			16, 1, kasan_reset_tag((void *)addr), length, 1);
 	metadata_access_disable();
 }
 
-- 
2.18.0


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