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

[Eddie James <eajames@linux.ibm.com>]

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 at 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>
>     wrote:
>     >
>     > From: Lixue Liang <lianglixue@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@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?
>

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


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