[PATCH] i2c: aspeed: Avoid accessing freed buffers during i2c transfers.

[Joel Stanley]

On Fri, 28 Jul 2023 at 12:40, Lixue Liang <lianglixuehao at 126.com> wrote:
>
> From: Lixue Liang <lianglixue at greatwall.com.cn>
>
> After waiting for the transmission timeout, the I2C controller will
> continue to transmit data when the bus is idle. Clearing bus->msg will
> avoid kernel panic when accessing the freed msg->buf in
> aspeed_i2c_master_irq.
>
> Signed-off-by: Lixue Liang <lianglixue at greatwall.com.cn>
> ---
>  drivers/i2c/busses/i2c-aspeed.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/i2c/busses/i2c-aspeed.c b/drivers/i2c/busses/i2c-aspeed.c
> index 2e5acfeb76c8..c83057497e26 100644
> --- a/drivers/i2c/busses/i2c-aspeed.c
> +++ b/drivers/i2c/busses/i2c-aspeed.c
> @@ -713,6 +713,8 @@ static int aspeed_i2c_master_xfer(struct i2c_adapter *adap,
>                 spin_lock_irqsave(&bus->lock, flags);
>                 if (bus->master_state == ASPEED_I2C_MASTER_PENDING)
>                         bus->master_state = ASPEED_I2C_MASTER_INACTIVE;
> +
> +               bus->msgs = NULL;

Eddie, is this the same issue you were debugging?

>                 spin_unlock_irqrestore(&bus->lock, flags);
>
>                 return -ETIMEDOUT;
> --
> 2.27.0
>