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

From: Eddie James
Date: Wed Aug 02 2023 - 09:44:39 EST



On 7/31/23 01:10, Lei YU wrote:
There is a same fix in https: //lore. kernel. org/openbmc/374237cb-1cda-df12-eb9f-7422cab51fc4@ linux. alibaba. com/ On Mon, Jul 31, 2023 at 12: 21 PM Joel Stanley <joel@ jms. id. au> wrote: On Fri, 28 Jul 2023 at 12: 40, Lixue Liang <lianglixuehao@ 126. com>
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There is a same fix in https://lore.kernel.org/openbmc/374237cb-1cda-df12-eb9f-7422cab51fc4@xxxxxxxxxxxxxxxxx/

On Mon, Jul 31, 2023 at 12:21 PM Joel Stanley <joel@xxxxxxxxx> wrote:

On Fri, 28 Jul 2023 at 12:40, Lixue Liang <lianglixuehao@xxxxxxx>
wrote:
>
> From: Lixue Liang <lianglixue@xxxxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxxx>
> ---
>  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?


Yes, it is, and the same fix I settled on.



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