The patch titled
Subject: kasan: remove vmalloc_percpu test
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
kasan-remove-vmalloc_percpu-test.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kasan-remove-vmalloc_percpu-test.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Subject: kasan: remove vmalloc_percpu test
Date: Tue, 22 Oct 2024 18:07:06 +0200
Commit 1a2473f0cbc0 ("kasan: improve vmalloc tests") added the
vmalloc_percpu KASAN test with the assumption that __alloc_percpu always
uses vmalloc internally, which is tagged by KASAN.
However, __alloc_percpu might allocate memory from the first per-CPU
chunk, which is not allocated via vmalloc(). As a result, the test might
fail.
Remove the test until proper KASAN annotation for the per-CPU allocated
are added; tracked in https://bugzilla.kernel.org/show_bug.cgi?id=215019.
Link: https://lkml.kernel.org/r/20241022160706.38943-1-andrey.konovalov@xxxxxxxxx
Fixes: 1a2473f0cbc0 ("kasan: improve vmalloc tests")
Signed-off-by: Andrey Konovalov <andreyknvl@xxxxxxxxx>
Reported-by: Samuel Holland <samuel.holland@xxxxxxxxxx>
Link: https://lore.kernel.org/all/4a245fff-cc46-44d1-a5f9-fd2f1c3764ae@xxxxxxxxxx/
Reported-by: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
Link: https://lore.kernel.org/all/CACzwLxiWzNqPBp4C1VkaXZ2wDwvY3yZeetCi1TLGFipKW77drA@xxxxxxxxxxxxxx/
Cc: Alexander Potapenko <glider@xxxxxxxxxx>
Cc: Andrey Ryabinin <ryabinin.a.a@xxxxxxxxx>
Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: Sabyrzhan Tasbolatov <snovitoll@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/kasan/kasan_test_c.c | 27 ---------------------------
1 file changed, 27 deletions(-)
--- a/mm/kasan/kasan_test_c.c~kasan-remove-vmalloc_percpu-test
+++ a/mm/kasan/kasan_test_c.c
@@ -1810,32 +1810,6 @@ static void vm_map_ram_tags(struct kunit
free_pages((unsigned long)p_ptr, 1);
}
-static void vmalloc_percpu(struct kunit *test)
-{
- char __percpu *ptr;
- int cpu;
-
- /*
- * This test is specifically crafted for the software tag-based mode,
- * the only tag-based mode that poisons percpu mappings.
- */
- KASAN_TEST_NEEDS_CONFIG_ON(test, CONFIG_KASAN_SW_TAGS);
-
- ptr = __alloc_percpu(PAGE_SIZE, PAGE_SIZE);
-
- for_each_possible_cpu(cpu) {
- char *c_ptr = per_cpu_ptr(ptr, cpu);
-
- KUNIT_EXPECT_GE(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_MIN);
- KUNIT_EXPECT_LT(test, (u8)get_tag(c_ptr), (u8)KASAN_TAG_KERNEL);
-
- /* Make sure that in-bounds accesses don't crash the kernel. */
- *c_ptr = 0;
- }
-
- free_percpu(ptr);
-}
-
/*
* Check that the assigned pointer tag falls within the [KASAN_TAG_MIN,
* KASAN_TAG_KERNEL) range (note: excluding the match-all tag) for tag-based
@@ -2023,7 +1997,6 @@ static struct kunit_case kasan_kunit_tes
KUNIT_CASE(vmalloc_oob),
KUNIT_CASE(vmap_tags),
KUNIT_CASE(vm_map_ram_tags),
- KUNIT_CASE(vmalloc_percpu),
KUNIT_CASE(match_all_not_assigned),
KUNIT_CASE(match_all_ptr_tag),
KUNIT_CASE(match_all_mem_tag),
_
Patches currently in -mm which might be from andreyknvl@xxxxxxxxx are
kasan-remove-vmalloc_percpu-test.patch
