[PATCH] clk: airoha: fix off-by-one in clock ID boundary check

[PATCH] clk: airoha: fix off-by-one in clock ID boundary check

[Wayen Yan]

The boundary checks in airoha_clk_enable(), airoha_clk_get_rate(), and
airoha_clk_set_rate() use "id > data->num_clocks" which allows id equal
to num_clocks to pass. Since data->descs[] has exactly num_clocks entries
(indices 0 to num_clocks-1), id=num_clocks results in an out-of-bounds
array access.

This is currently not triggered because the device tree clock IDs are
within bounds, but the check should be defensive. Fix by changing the
comparison from ">" to ">=".

Fixes: d0b81afb5ec9 ("clk: airoha: Add support for Airoha AN7581 SoC clock")
Signed-off-by: Wayen Yan <win847@gmail.com>
---
 drivers/clk/airoha/clk-airoha.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/clk/airoha/clk-airoha.c b/drivers/clk/airoha/clk-airoha.c
index 49dbca82135..89a8b4cb1cf 100644
--- a/drivers/clk/airoha/clk-airoha.c
+++ b/drivers/clk/airoha/clk-airoha.c
@@ -327,7 +327,7 @@ static int airoha_clk_enable(struct clk *clk)
 	struct airoha_clk_soc_data *data = priv->data;
 	int id = clk->id;
 
-	if (id > data->num_clocks)
+	if (id >= data->num_clocks)
 		return -EINVAL;
 
 	return 0;
@@ -349,7 +349,7 @@ static ulong airoha_clk_get_rate(struct clk *clk)
 	ulong rate;
 	int ret;
 
-	if (id > data->num_clocks) {
+	if (id >= data->num_clocks) {
 		dev_err(clk->dev, "Invalid clk ID %d\n", id);
 		return 0;
 	}
@@ -412,7 +412,7 @@ static ulong airoha_clk_set_rate(struct clk *clk, ulong rate)
 	int div;
 	int ret;
 
-	if (id > data->num_clocks) {
+	if (id >= data->num_clocks) {
 		dev_err(clk->dev, "Invalid clk ID %d\n", id);
 		return 0;
 	}
-- 
2.51.0

Re: [PATCH] clk: airoha: fix off-by-one in clock ID boundary check

[Tom Rini]

On Wed, 08 Jul 2026 12:06:08 +0800, Wayen Yan wrote:

> The boundary checks in airoha_clk_enable(), airoha_clk_get_rate(), and
> airoha_clk_set_rate() use "id > data->num_clocks" which allows id equal
> to num_clocks to pass. Since data->descs[] has exactly num_clocks entries
> (indices 0 to num_clocks-1), id=num_clocks results in an out-of-bounds
> array access.
> 
> This is currently not triggered because the device tree clock IDs are
> within bounds, but the check should be defensive. Fix by changing the
> comparison from ">" to ">=".
> 
> [...]

Applied to u-boot/main, thanks!

[1/1] clk: airoha: fix off-by-one in clock ID boundary check
      commit: fdfe2ec48d5c1c2ed03073d73edd3fdd3fe1ffa1
-- 
Tom