From 795469820c638b4449f3bb90ee5e98ebccfbc480 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Mon, 23 Feb 2026 14:01:56 -0800 Subject: kcsan: test: Adjust "expect" allocation type for kmalloc_obj The call to kmalloc_obj(observed.lines) returns "char (*)[3][512]", a pointer to the whole 2D array. But "expect" wants to be "char (*)[512]", the decayed pointer type, as if it were observed.lines itself (though without the "3" bounds). This produces the following build error: ../kernel/kcsan/kcsan_test.c: In function '__report_matches': ../kernel/kcsan/kcsan_test.c:171:16: error: assignment to 'char (*)[512]' from incompatible pointer type 'char (*)[3][512]' [-Wincompatible-pointer-types] 171 | expect = kmalloc_obj(observed.lines); | ^ Instead of changing the "expect" type to "char (*)[3][512]" and requiring a dereference at each use (e.g. "(expect*)[0]"), just explicitly cast the return to the desired type. Note that I'm intentionally not switching back to byte-based "kmalloc" here because I cannot find a way for the Coccinelle script (which will be used going forward to catch future conversions) to exclude this case. Tested with: $ ./tools/testing/kunit/kunit.py run \ --kconfig_add CONFIG_DEBUG_KERNEL=y \ --kconfig_add CONFIG_KCSAN=y \ --kconfig_add CONFIG_KCSAN_KUNIT_TEST=y \ --arch=x86_64 --qemu_args '-smp 2' kcsan Reported-by: Nathan Chancellor Fixes: 69050f8d6d07 ("treewide: Replace kmalloc with kmalloc_obj for non-scalar types") Signed-off-by: Kees Cook --- kernel/kcsan/kcsan_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c index 79e655ea4ca1..ae758150ccb9 100644 --- a/kernel/kcsan/kcsan_test.c +++ b/kernel/kcsan/kcsan_test.c @@ -168,7 +168,7 @@ static bool __report_matches(const struct expect_report *r) if (!report_available()) return false; - expect = kmalloc_obj(observed.lines); + expect = (typeof(expect))kmalloc_obj(observed.lines); if (WARN_ON(!expect)) return false; -- cgit v1.2.3