+ kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch added to -mm tree

+ kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch added to -mm tree

[akpm]

The patch titled
     Subject: kasan: test: avoid corrupting memory in kasan_rcu_uaf
has been added to the -mm tree.  Its filename is
     kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch

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------------------------------------------------------
From: Andrey Konovalov <andreyknvl@gmail.com>
Subject: kasan: test: avoid corrupting memory in kasan_rcu_uaf

kasan_rcu_uaf() writes to freed memory via kasan_rcu_reclaim(), which is
only safe with the GENERIC mode (as it uses quarantine).  For other modes,
this test corrupts kernel memory, which might result in a crash.

Turn the write into a read.

Link: https://lkml.kernel.org/r/b6f2c3bf712d2457c783fa59498225b66a634f62.1628779805.git.andreyknvl@gmail.com
Signed-off-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Marco Elver <elver@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Ryabinin <aryabinin@virtuozzo.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/test_kasan_module.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/lib/test_kasan_module.c~kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf
+++ a/lib/test_kasan_module.c
@@ -71,7 +71,7 @@ static noinline void __init kasan_rcu_re
 						struct kasan_rcu_info, rcu);
 
 	kfree(fp);
-	fp->i = 1;
+	((volatile struct kasan_rcu_info *)fp)->i;
 }
 
 static noinline void __init kasan_rcu_uaf(void)
_

Patches currently in -mm which might be from andreyknvl@gmail.com are

kasan-test-rework-kmalloc_oob_right.patch
kasan-test-avoid-writing-invalid-memory.patch
kasan-test-avoid-corrupting-memory-via-memset.patch
kasan-test-disable-kmalloc_memmove_invalid_size-for-hw_tags.patch
kasan-test-only-do-kmalloc_uaf_memset-for-generic-mode.patch
kasan-test-clean-up-ksize_uaf.patch
kasan-test-avoid-corrupting-memory-in-copy_user_test.patch
kasan-test-avoid-corrupting-memory-in-kasan_rcu_uaf.patch