On Mon, Nov 24, 2025 at 1:11 PM Nathan Chancellor <[email protected]> wrote: > > 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: [email protected] > Fixes: f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with > __counted_by") > Reported-by: Jochen Sprickerhof <[email protected]> > Closes: https://lore.kernel.org/[email protected]/ > Tested-by: Jochen Sprickerhof <[email protected]> > Signed-off-by: Nathan Chancellor <[email protected]> > ---
Reviewed-by: Sam Protsenko <[email protected]> > drivers/clk/samsung/clk-exynos-clkout.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/clk/samsung/clk-exynos-clkout.c > b/drivers/clk/samsung/clk-exynos-clkout.c > index 5f1a4f5e2e59..5b21025338bd 100644 > --- a/drivers/clk/samsung/clk-exynos-clkout.c > +++ b/drivers/clk/samsung/clk-exynos-clkout.c > @@ -175,6 +175,7 @@ static int exynos_clkout_probe(struct platform_device > *pdev) > 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, > @@ -185,7 +186,6 @@ static int exynos_clkout_probe(struct platform_device > *pdev) > 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; > > --- > base-commit: b6430552c8cd95e90bb842ce2f421e7a5381859f > change-id: 20251124-exynos-clkout-fix-ubsan-bounds-error-93071375ec78 > > Best regards, > -- > Nathan Chancellor <[email protected]> > >
