[PATCH v1] clk: microchip: mpfs-ccc: fix out of bounds access during output registration

[Conor Dooley]

UBSAN reported an out of bounds access during registration of the last
two outputs. This out of bounds access occurs because space is only
allocated in the hws array for two PLLs and the four output dividers
that each has, but the defined IDs contain two DLLS and their two
outputs each, which are not supported by the driver. The ID order is
PLLs -> DLLs -> PLL outputs -> DLL outputs. Decrement the PLL output IDs
by two while adding them to the array to avoid the problem.

Fixes: d39fb172760e ("clk: microchip: add PolarFire SoC fabric clock support")
CC: stable@xxxxxxxxxxxxxxx
Signed-off-by: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
---
CC: Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
CC: Daire McNamara <daire.mcnamara@xxxxxxxxxxxxx>
CC: Michael Turquette <mturquette@xxxxxxxxxxxx>
CC: Stephen Boyd <sboyd@xxxxxxxxxx>
CC: Claudiu Beznea <claudiu.beznea@xxxxxxxxx>
CC: linux-riscv@xxxxxxxxxxxxxxxxxxx
CC: linux-clk@xxxxxxxxxxxxxxx
CC: linux-kernel@xxxxxxxxxxxxxxx
---
 drivers/clk/microchip/clk-mpfs-ccc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/microchip/clk-mpfs-ccc.c b/drivers/clk/microchip/clk-mpfs-ccc.c
index 3a3ea2d142f8a..54cfbb8be8ab5 100644
--- a/drivers/clk/microchip/clk-mpfs-ccc.c
+++ b/drivers/clk/microchip/clk-mpfs-ccc.c
@@ -178,7 +178,7 @@ static int mpfs_ccc_register_outputs(struct device *dev, struct mpfs_ccc_out_hw_
 			return dev_err_probe(dev, ret, "failed to register clock id: %d\n",
 					     out_hw->id);
 
-		data->hw_data.hws[out_hw->id] = &out_hw->divider.hw;
+		data->hw_data.hws[out_hw->id - 2] = &out_hw->divider.hw;
 	}
 
 	return 0;
-- 
2.51.0