The patch titled
Subject: kasan, mm: fix conflicts with init_on_alloc/free
has been added to the -mm tree. Its filename is
kasan-mm-fix-conflicts-with-init_on_alloc-free.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/kasan-mm-fix-conflicts-with-init_on_alloc-free.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/kasan-mm-fix-conflicts-with-init_on_alloc-free.patch
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Subject: kasan, mm: fix conflicts with init_on_alloc/free
A few places where SLUB accesses object's data or metadata were missed in
a previous patch. This leads to false positives with hardware tag-based
KASAN when bulk allocations are used with init_on_alloc/free.
Fix the false-positives by resetting pointer tags during these accesses.
(The kasan_reset_tag call is removed from slab_alloc_node, as it's added
into maybe_wipe_obj_freeptr.)
Link: https://linux-review.googlesource.com/id/I50dd32838a666e173fe06c3c5c766f2c36aae901
Link: https://lkml.kernel.org/r/093428b5d2ca8b507f4a79f92f9929b35f7fada7.1610731872.git.andreyknvl@xxxxxxxxxx
Fixes: aa1ef4d7b3f67 ("kasan, mm: reset tags when accessing metadata")
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Reported-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Vincenzo Frascino <vincenzo.frascino@xxxxxxx>
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Andrey Ryabinin <aryabinin@xxxxxxxxxxxxx>
Cc: Peter Collingbourne <pcc@xxxxxxxxxx>
Cc: Evgenii Stepanov <eugenis@xxxxxxxxxx>
Cc: Branislav Rankov <Branislav.Rankov@xxxxxxx>
Cc: Kevin Brodsky <kevin.brodsky@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/slub.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/mm/slub.c~kasan-mm-fix-conflicts-with-init_on_alloc-free
+++ a/mm/slub.c
@@ -2791,7 +2791,8 @@ static __always_inline void maybe_wipe_o
void *obj)
{
if (unlikely(slab_want_init_on_free(s)) && obj)
- memset((void *)((char *)obj + s->offset), 0, sizeof(void *));
+ memset((void *)((char *)kasan_reset_tag(obj) + s->offset),
+ 0, sizeof(void *));
}
/*
@@ -2883,7 +2884,7 @@ redo:
stat(s, ALLOC_FASTPATH);
}
- maybe_wipe_obj_freeptr(s, kasan_reset_tag(object));
+ maybe_wipe_obj_freeptr(s, object);
if (unlikely(slab_want_init_on_alloc(gfpflags, s)) && object)
memset(kasan_reset_tag(object), 0, s->object_size);
@@ -3329,7 +3330,7 @@ int kmem_cache_alloc_bulk(struct kmem_ca
int j;
for (j = 0; j < i; j++)
- memset(p[j], 0, s->object_size);
+ memset(kasan_reset_tag(p[j]), 0, s->object_size);
}
/* memcg and kmem_cache debug support */
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxxx are
kasan-fix-hw_tags-boot-parameters.patch
kasan-mm-fix-conflicts-with-init_on_alloc-free.patch
kasan-prefix-global-functions-with-kasan_.patch
kasan-clarify-hw_tags-impact-on-tbi.patch
kasan-clean-up-comments-in-tests.patch
kasan-add-macros-to-simplify-checking-test-constraints.patch
kasan-add-match-all-tag-tests.patch
kasan-arm64-allow-using-kunit-tests-with-hw_tags-mode.patch
kasan-rename-config_test_kasan_module.patch
kasan-add-compiler-barriers-to-kunit_expect_kasan_fail.patch
kasan-adapt-kmalloc_uaf2-test-to-hw_tags-mode.patch
kasan-fix-memory-corruption-in-kasan_bitops_tags-test.patch
kasan-move-_ret_ip_-to-inline-wrappers.patch
kasan-fix-bug-detection-via-ksize-for-hw_tags-mode.patch
kasan-add-proper-page-allocator-tests.patch
kasan-add-a-test-for-kmem_cache_alloc-free_bulk.patch
kasan-dont-run-tests-when-kasan-is-not-enabled.patch
