kunit/overflow: fix UB in overflow_allocation_test

The 'device_name' array doesn't exist out of the
'overflow_allocation_test' function scope.  However, it is being used
as a driver name when calling 'kunit_driver_create' from
'kunit_device_register'.  It produces the kernel panic with KASAN
enabled due to undefined behaviour.

Since this variable is used in one place only, remove it and pass the
device name into kunit_device_register directly as an ascii string.

Link: https://lkml.kernel.org/r/20240815000431.401869-1-ivan.orlov0322@gmail.com
Fixes: ca90800a91ba ("test_overflow: Add memory allocation overflow tests")
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Tested-by: Erhard Furtner <erhard_f@mailbox.org>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/lib/overflow_kunit.c b/lib/overflow_kunit.c
index f314a0c15a6d83d8fff4a71b71347fba6da112f2..2abc78367dd110cf8aaaa86190ee9a6248786441 100644 (file)
--- a/lib/overflow_kunit.c
+++ b/lib/overflow_kunit.c
@@ -668,7 +668,6 @@ DEFINE_TEST_ALLOC(devm_kzalloc,  devm_kfree, 1, 1, 0);
 
 static void overflow_allocation_test(struct kunit *test)
 {
-       const char device_name[] = "overflow-test";
        struct device *dev;
        int count = 0;
 
@@ -678,7 +677,7 @@ static void overflow_allocation_test(struct kunit *test)
 } while (0)
 
        /* Create dummy device for devm_kmalloc()-family tests. */
-       dev = kunit_device_register(test, device_name);
+       dev = kunit_device_register(test, "overflow-test");
        KUNIT_ASSERT_FALSE_MSG(test, IS_ERR(dev),
                               "Cannot register test device\n");