The patch titled
Subject: kasan: fix tag for large allocations when using CONFIG_SLAB
has been added to the -mm tree. Its filename is
kasan-fix-tag-for-large-allocations-when-using-config_slab.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-fix-tag-for-large-allocations-when-using-config_slab.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-fix-tag-for-large-allocations-when-using-config_slab.patch
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next and is updated
there every 3-4 working days
------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: kasan: fix tag for large allocations when using CONFIG_SLAB
If an object is allocated on a tail page of a multi-page slab, kasan will
get the wrong tag because page->s_mem is NULL for tail pages. I'm not
quite sure what the user-visible effect of this might be.
Link: https://lkml.kernel.org/r/20211001024105.3217339-1-willy@xxxxxxxxxxxxx
Fixes: 7f94ffbc4c6a ("kasan: add hooks implementation for tag-based mode")
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Acked-by: Marco Elver <elver@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/common.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/kasan/common.c~kasan-fix-tag-for-large-allocations-when-using-config_slab
+++ a/mm/kasan/common.c
@@ -298,7 +298,7 @@ static inline u8 assign_tag(struct kmem_
/* For caches that either have a constructor or SLAB_TYPESAFE_BY_RCU: */
#ifdef CONFIG_SLAB
/* For SLAB assign tags based on the object index in the freelist. */
- return (u8)obj_to_index(cache, virt_to_page(object), (void *)object);
+ return (u8)obj_to_index(cache, virt_to_head_page(object), (void *)object);
#else
/*
* For SLUB assign a random tag during slab creation, otherwise reuse
_
Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are
mm-move-kvmalloc-related-functions-to-slabh.patch
mm-remove-bogus-vm_bug_on.patch
kasan-fix-tag-for-large-allocations-when-using-config_slab.patch
