[PATCH v2] kasan: fix bad call to unpoison_slab_object

From: andrey . konovalov
Date: Fri Jun 14 2024 - 10:33:00 EST


From: Andrey Konovalov <andreyknvl@xxxxxxxxx>

Commit 29d7355a9d05 ("kasan: save alloc stack traces for mempool") messed
up one of the calls to unpoison_slab_object: the last two arguments are
supposed to be GFP flags and whether to init the object memory.

Fix the call.

Without this fix, __kasan_mempool_unpoison_object provides the object's
size as GFP flags to unpoison_slab_object, which can cause LOCKDEP
reports (and probably other issues).

Fixes: 29d7355a9d05 ("kasan: save alloc stack traces for mempool")
Reported-by: Brad Spengler <spender@xxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Acked-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>

---

Changes v1->v2:
- Fix typo in commit message.
- CC stable.
---
mm/kasan/common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/kasan/common.c b/mm/kasan/common.c
index e7c9a4dc89f8..85e7c6b4575c 100644
--- a/mm/kasan/common.c
+++ b/mm/kasan/common.c
@@ -532,7 +532,7 @@ void __kasan_mempool_unpoison_object(void *ptr, size_t size, unsigned long ip)
return;

/* Unpoison the object and save alloc info for non-kmalloc() allocations. */
- unpoison_slab_object(slab->slab_cache, ptr, size, flags);
+ unpoison_slab_object(slab->slab_cache, ptr, flags, false);

/* Poison the redzone and save alloc info for kmalloc() allocations. */
if (is_kmalloc_cache(slab->slab_cache))
--
2.25.1