Re: [PATCH v3] mtd: rawnand: meson: initialize struct with zeroes

[Neil Armstrong]

On 27/02/2023 10:59, Arseniy Krasnov wrote:
> This structure must be zeroed, because it's field 'hw->core' is used as
> 'parent' in 'clk_core_fill_parent_index()', but it will be uninitialized.
> This happens, because when this struct is not zeroed, pointer 'hw' is
> "initialized" by garbage, which is valid pointer, but points to some
> garbage. So 'hw' will be dereferenced, but 'core' contains some random
> data which will be interpreted as a pointer. The following backtrace is
> result of dereference of such pointer:
>
> [    1.081319]  __clk_register+0x414/0x820
> [    1.085113]  devm_clk_register+0x64/0xd0
> [    1.088995]  meson_nfc_probe+0x258/0x6ec
> [    1.092875]  platform_probe+0x70/0xf0
> [    1.096498]  really_probe+0xc8/0x3e0
> [    1.100034]  __driver_probe_device+0x84/0x190
> [    1.104346]  driver_probe_device+0x44/0x120
> [    1.108487]  __driver_attach+0xb4/0x220
> [    1.112282]  bus_for_each_dev+0x78/0xd0
> [    1.116077]  driver_attach+0x2c/0x40
> [    1.119613]  bus_add_driver+0x184/0x240
> [    1.123408]  driver_register+0x80/0x140
> [    1.127203]  __platform_driver_register+0x30/0x40
> [    1.131860]  meson_nfc_driver_init+0x24/0x30
>
> Fixes: 1e4d3ba66888 ("mtd: rawnand: meson: fix the clock")
> Signed-off-by: Arseniy Krasnov <AVKrasnov@xxxxxxxxxxxxxx>
> Acked-by: Martin Blumenstingl <martin.blumenstingl@xxxxxxxxxxxxxx>
> ---
>   drivers/mtd/nand/raw/meson_nand.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/raw/meson_nand.c b/drivers/mtd/nand/raw/meson_nand.c
> index 5ee01231ac4c..30e326adabfc 100644
> --- a/drivers/mtd/nand/raw/meson_nand.c
> +++ b/drivers/mtd/nand/raw/meson_nand.c
> @@ -991,7 +991,7 @@ static const struct mtd_ooblayout_ops meson_ooblayout_ops = {
>   
>   static int meson_nfc_clk_init(struct meson_nfc *nfc)
>   {
> -	struct clk_parent_data nfc_divider_parent_data[1];
> +	struct clk_parent_data nfc_divider_parent_data[1] = {0};
>   	struct clk_init_data init = {0};
>   	int ret;
>   

Reviewed-by: Neil Armstrong <neil.armstrong@xxxxxxxxxx>