| Message ID | 20220713154953.3336-2-stefan.wahren@i2se.com (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
| Series | clk: bcm: rpi: Fixes and improvement | expand |
On 7/13/22 08:49, Stefan Wahren wrote: > 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 <phil@raspberrypi.com> > Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Quoting Stefan Wahren (2022-07-13 08:49:51) > 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 <phil@raspberrypi.com> > Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> > --- Applied to clk-fixes
diff --git a/drivers/clk/bcm/clk-raspberrypi.c b/drivers/clk/bcm/clk-raspberrypi.c index 73518009a0f2..79cbf0c0b401 100644 --- a/drivers/clk/bcm/clk-raspberrypi.c +++ b/drivers/clk/bcm/clk-raspberrypi.c @@ -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;
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 <phil@raspberrypi.com> Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> --- drivers/clk/bcm/clk-raspberrypi.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)