ACK: [SRU][F:linux-bluefield][PATCH v2 1/1] UBUNTU: SAUCE: i2c-mlxbf.c: prevent stack overflow in mlxbf_i2c_smbus_start_transaction()

[Kleber Souza]

On 02.07.21 15:04, Asmaa Mnebhi wrote:
> BugLink: https://bugs.launchpad.net/bugs/1934304
> 
> There could be stack overflow in mlxbf_i2c_smbus_start_transaction().
> memcpy() is called in a loop while 'operation->length' upper bound is not checked and 'data_idx' also increments.
> 
> Reviewed-by: Khalil Blaiech <kblaiech at nvidia.com>
> Signed-off-by: Asmaa Mnebhi <asmaa at nvidia.com>

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>

Thanks

> 
> ---
>   drivers/i2c/busses/i2c-mlxbf.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-mlxbf.c b/drivers/i2c/busses/i2c-mlxbf.c
> index d3c7bc21e941..05c3025c9772 100644
> --- a/drivers/i2c/busses/i2c-mlxbf.c
> +++ b/drivers/i2c/busses/i2c-mlxbf.c
> @@ -770,6 +770,8 @@ static int mlx_smbus_start_transaction(struct mlx_i2c_priv *priv,
>   		if (flags & I2C_F_WRITE) {
>   			write_en   = 1;
>   			write_len += operation->length;
> +			if (data_idx + operation->length > MASTER_DATA_DESC_SIZE)
> +				return -ENOBUFS;
>   			memcpy(data_desc + data_idx,
>   			       operation->buffer, operation->length);
>   			data_idx  += operation->length;
>