clk: bcm: rpi: Prevent out-of-bounds access

The while loop in raspberrypi_discover_clocks() relies on the assumption
that the id of the last clock element is zero. Because this data comes
from the Videocore firmware and it doesn't guarantuee such a behavior
this could lead to out-of-bounds access. So fix this by providing
a sentinel element.

Fixes: 93d2725aff ("clk: bcm: rpi: Discover the firmware clocks")
Link: https://github.com/raspberrypi/firmware/issues/1688
Suggested-by: Phil Elwell <phil@raspberrypi.com>
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20220713154953.3336-2-stefan.wahren@i2se.com
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Ivan T. Ivanov <iivanov@suse.de>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
This commit is contained in:
Stefan Wahren 2022-07-13 17:49:51 +02:00 committed by Stephen Boyd
parent 35f73cca1c
commit bc16355560

View file

@ -344,8 +344,13 @@ static int raspberrypi_discover_clocks(struct raspberrypi_clk *rpi,
struct rpi_firmware_get_clocks_response *clks;
int ret;
/*
* The firmware doesn't guarantee that the last element of
* RPI_FIRMWARE_GET_CLOCKS is zeroed. So allocate an additional
* zero element as sentinel.
*/
clks = devm_kcalloc(rpi->dev,
RPI_FIRMWARE_NUM_CLK_ID, sizeof(*clks),
RPI_FIRMWARE_NUM_CLK_ID + 1, sizeof(*clks),
GFP_KERNEL);
if (!clks)
return -ENOMEM;