[PATCH 5.11 364/601] clk: uniphier: Fix potential infinite loop

From: Greg Kroah-Hartman
Date: Wed May 12 2021 - 13:41:54 EST


From: Colin Ian King <colin.king@xxxxxxxxxxxxx>

[ 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@xxxxxxxxxxxxx>
Reviewed-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210409090104.629722-1-colin.king@xxxxxxxxxxxxx
Signed-off-by: Stephen Boyd <sboyd@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 462c84321b2d..1998e9d4cfc0 100644
--- a/drivers/clk/uniphier/clk-uniphier-mux.c
+++ b/drivers/clk/uniphier/clk-uniphier-mux.c
@@ -31,10 +31,10 @@ 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