Commit bc163555 authored by Stefan Wahren's avatar Stefan Wahren Committed by Stephen Boyd
Browse files

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: 93d2725a ("clk: bcm: rpi: Discover the firmware clocks")
Link: https://github.com/raspberrypi/firmware/issues/1688


Suggested-by: default avatarPhil Elwell <phil@raspberrypi.com>
Signed-off-by: default avatarStefan Wahren <stefan.wahren@i2se.com>
Link: https://lore.kernel.org/r/20220713154953.3336-2-stefan.wahren@i2se.com


Acked-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Reviewed-by: default avatarIvan T. Ivanov <iivanov@suse.de>
Signed-off-by: default avatarStephen Boyd <sboyd@kernel.org>
parent 35f73cca

drivers/clk/bcm/clk-raspberrypi.c

+6 −1
Original line number Diff line number Diff line
@@ -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;