From ff0b144d4b0a9fbd6efe4d2c0a4b6c9bae2138d2 Mon Sep 17 00:00:00 2001 From: Stefan Wahren Date: Wed, 13 Jul 2022 17:49:51 +0200 Subject: [PATCH] clk: bcm: rpi: Prevent out-of-bounds access [ Upstream commit bc163555603e4ae9c817675ad80d618a4cdbfa2d ] 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: 93d2725affd6 ("clk: bcm: rpi: Discover the firmware clocks") Link: https://github.com/raspberrypi/firmware/issues/1688 Suggested-by: Phil Elwell Signed-off-by: Stefan Wahren Link: https://lore.kernel.org/r/20220713154953.3336-2-stefan.wahren@i2se.com Acked-by: Florian Fainelli Reviewed-by: Ivan T. Ivanov Signed-off-by: Stephen Boyd Signed-off-by: Sasha Levin --- drivers/clk/bcm/clk-raspberrypi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c index 97612860ce0e1..834bcc256e921 100644 --- a/drivers/clk/bcm/clk-raspberrypi.c +++ b/drivers/clk/bcm/clk-raspberrypi.c @@ -251,8 +251,13 @@ 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;