[PATCH 4.9 131/240] clk: uniphier: Fix potential infinite loop

Greg Kroah-Hartman
2021-05-20T11:16:22Z

From: Colin Ian King <colin.king@canonical.com>

[ Upstream commit f6b1340dc751a6caa2a0567b667d0f4f4172cd58 ]

The for-loop iterates with a u8 loop counter i and compares this
with the loop upper limit of num_parents that is an int type.
There is a potential infinite loop if num_parents is larger than
the u8 loop counter. Fix this by making the loop counter the same
type as num_parents. Also make num_parents an unsigned int to
match the return type of the call to clk_hw_get_num_parents.

Addresses-Coverity: ("Infinite loop")
Fixes: 734d82f4a678 ("clk: uniphier: add core support code for UniPhier clock driver")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210409090104.629722-1-colin.king@canonical.com
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/clk/uniphier/clk-uniphier-mux.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/uniphier/clk-uniphier-mux.c b/drivers/clk/uniphier/clk-uniphier-mux.c
index 2c243a894f3b..3a52ab968ac2 100644
--- a/drivers/clk/uniphier/clk-uniphier-mux.c
+++ b/drivers/clk/uniphier/clk-uniphier-mux.c
@@ -40,10 +40,10 @@ static int uniphier_clk_mux_set_parent(struct clk_hw *hw, u8 index)
static u8 uniphier_clk_mux_get_parent(struct clk_hw *hw)
{
struct uniphier_clk_mux *mux = to_uniphier_clk_mux(hw);
- int num_parents = clk_hw_get_num_parents(hw);
+ unsigned int num_parents = clk_hw_get_num_parents(hw);
int ret;
unsigned int val;
- u8 i;
+ unsigned int i;

ret = regmap_read(mux->regmap, mux->reg, &val);
if (ret)
--
2.30.2