clk: bcm: dvp: Assign ->num before accessing ->hws

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 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
clk_dvp_probe() due to ->num being assigned after ->hws has been
accessed:

  UBSAN: array-index-out-of-bounds in drivers/clk/bcm/clk-bcm2711-dvp.c:59:2
  index 0 is out of range for type 'struct clk_hw *[] __counted_by(num)' (aka 'struct clk_hw *[]')

Move the ->num initialization to before the first access of ->hws, which
clears up the warning.

Cc: stable@vger.kernel.org
Fixes: f316cdff8d67 ("clk: Annotate struct clk_hw_onecell_data with __counted_by")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20240425-cbl-bcm-assign-counted-by-val-before-access-v1-1-e2db3b82d5ef@kernel.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

diff --git a/drivers/clk/bcm/clk-bcm2711-dvp.c b/drivers/clk/bcm/clk-bcm2711-dvp.c
index e4fbbf3c40fe2b1a3175a089f2f08642340824a3..3cb235df9d379f88db0ed31f3b8190476629bb3f 100644 (file)
--- a/drivers/clk/bcm/clk-bcm2711-dvp.c
+++ b/drivers/clk/bcm/clk-bcm2711-dvp.c
@@ -56,6 +56,8 @@ static int clk_dvp_probe(struct platform_device *pdev)
        if (ret)
                return ret;
 
+       data->num = NR_CLOCKS;
+
        data->hws[0] = clk_hw_register_gate_parent_data(&pdev->dev,
                                                        "hdmi0-108MHz",
                                                        &clk_dvp_parent, 0,
@@ -76,7 +78,6 @@ static int clk_dvp_probe(struct platform_device *pdev)
                goto unregister_clk0;
        }
 
-       data->num = NR_CLOCKS;
        ret = of_clk_add_hw_provider(pdev->dev.of_node, of_clk_hw_onecell_get,
                                     data);
        if (ret)