[PATCH 6.12 379/567] clk: samsung: exynos-clkout: Assign .num before accessing .hws

Greg Kroah-Hartman
2026-01-06T17:35:16Z

From: Nathan Chancellor <nathan@kernel.org>

commit cf33f0b7df13685234ccea7be7bfe316b60db4db upstream.

Commit f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with
__counted_by") annotated the hws member of 'struct clk_hw_onecell_data'
with __counted_by, which informs the bounds sanitizer (UBSAN_BOUNDS)
about the number of elements in .hws[], so that it can warn when .hws[]
is accessed out of bounds. As noted in that change, the __counted_by
member must be initialized with the number of elements before the first
array access happens, otherwise there will be a warning from each access
prior to the initialization because the number of elements is zero. This
occurs in exynos_clkout_probe() due to .num being assigned after .hws[]
has been accessed:

UBSAN: array-index-out-of-bounds in drivers/clk/samsung/clk-exynos-clkout.c:178:18
index 0 is out of range for type 'clk_hw *[*]'

Move the .num initialization to before the first access of .hws[],
clearing up the warning.

Cc: stable@vger.kernel.org
Fixes: f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with __counted_by")
Reported-by: Jochen Sprickerhof <jochen@sprickerhof.de>
Closes: https://lore.kernel.org/aSIYDN5eyKFKoXKL@eldamar.lan/
Tested-by: Jochen Sprickerhof <jochen@sprickerhof.de>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Sam Protsenko <semen.protsenko@linaro.org>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/clk/samsung/clk-exynos-clkout.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/clk/samsung/clk-exynos-clkout.c
+++ b/drivers/clk/samsung/clk-exynos-clkout.c
@@ -174,6 +174,7 @@ static int exynos_clkout_probe(struct pl
clkout->mux.shift = EXYNOS_CLKOUT_MUX_SHIFT;
clkout->mux.lock = &clkout->slock;

+ clkout->data.num = EXYNOS_CLKOUT_NR_CLKS;
clkout->data.hws[0] = clk_hw_register_composite(NULL, "clkout",
parent_names, parent_count, &clkout->mux.hw,
&clk_mux_ops, NULL, NULL, &clkout->gate.hw,
@@ -184,7 +185,6 @@ static int exynos_clkout_probe(struct pl
goto err_unmap;
}

- clkout->data.num = EXYNOS_CLKOUT_NR_CLKS;
ret = of_clk_add_hw_provider(clkout->np, of_clk_hw_onecell_get, &clkout->data);
if (ret)
goto err_clk_unreg;