The 9FGV0841 has 8 outputs and registers 8 struct clk_hw, make sure
there are 8 slots for those newly registered clk_hw pointers, else
there is going to be out of bounds write when pointers 4..7 are set
into struct rs9_driver_data .clk_dif[4..7] field.

Since there are other structure members past this struct clk_hw
pointer array, writing to .clk_dif[4..7] fields corrupts both
the struct rs9_driver_data content and data around it, sometimes
without crashing the kernel. However, the kernel does surely
crash when the driver is unbound or during suspend.

Fix this, increase the struct clk_hw pointer array size to the
maximum output count of 9FGV0841, which is the biggest chip that
is supported by this driver.

Cc: stable@vger.kernel.org
Fixes: f0e5e1800204 ("clk: rs9: Add support for 9FGV0841")
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
---
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Michael Turquette <mturquette@baylibre.com>
Cc: Stephen Boyd <sboyd@kernel.org>
Cc: linux-clk@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-renesas-soc@vger.kernel.org
---
V2: - Update the commit message crash paragraph
    - Add RB/TB from Geert
---
 drivers/clk/clk-renesas-pcie.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/clk/clk-renesas-pcie.c b/drivers/clk/clk-renesas-pcie.c
index 4c3a5e4eb77ac..f94a9c4d0b670 100644
--- a/drivers/clk/clk-renesas-pcie.c
+++ b/drivers/clk/clk-renesas-pcie.c
@@ -64,7 +64,7 @@ struct rs9_driver_data {
 	struct i2c_client	*client;
 	struct regmap		*regmap;
 	const struct rs9_chip_info *chip_info;
-	struct clk_hw		*clk_dif[4];
+	struct clk_hw		*clk_dif[8];
 	u8			pll_amplitude;
 	u8			pll_ssc;
 	u8			clk_dif_sr;
-- 
2.51.0

On Mon, 19 Jan 2026 at 16:02, Marek Vasut
<marek.vasut+renesas@mailbox.org> wrote:
> The 9FGV0841 has 8 outputs and registers 8 struct clk_hw, make sure
> there are 8 slots for those newly registered clk_hw pointers, else
> there is going to be out of bounds write when pointers 4..7 are set
> into struct rs9_driver_data .clk_dif[4..7] field.
>
> Since there are other structure members past this struct clk_hw
> pointer array, writing to .clk_dif[4..7] fields corrupts both
> the struct rs9_driver_data content and data around it, sometimes
> without crashing the kernel. However, the kernel does surely
> crash when the driver is unbound or during suspend.
>
> Fix this, increase the struct clk_hw pointer array size to the
> maximum output count of 9FGV0841, which is the biggest chip that
> is supported by this driver.
>
> Cc: stable@vger.kernel.org
> Fixes: f0e5e1800204 ("clk: rs9: Add support for 9FGV0841")
> Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>

Closes: https://lore.kernel.org/CAMuHMdVyQpOBT+Ho+mXY07fndFN9bKJdaaWGn91WOFnnYErLyg@mail.gmail.com

> Signed-off-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
> ---
> Cc: Geert Uytterhoeven <geert+renesas@glider.be>
> Cc: Michael Turquette <mturquette@baylibre.com>
> Cc: Stephen Boyd <sboyd@kernel.org>
> Cc: linux-clk@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-renesas-soc@vger.kernel.org
> ---
> V2: - Update the commit message crash paragraph
>     - Add RB/TB from Geert

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds