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]>
---
 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]>


Reply via email to