diff mbox series

[v2] i2c: cpm: Fix i2c_ram structure

Message ID 20200923140840.8700-1-nicolas.vincent@vossloh.com (mailing list archive)
State Handled Elsewhere
Headers show
Series [v2] i2c: cpm: Fix i2c_ram structure | expand

Checks

Context Check Description
snowpatch_ozlabs/apply_patch success Successfully applied on branch powerpc/merge (ace1986562a0814f179ecd2f1e648215ebc6625a)
snowpatch_ozlabs/build-ppc64le warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/build-ppc64be warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/build-ppc64e warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/build-pmac32 warning Upstream build failed, couldn't test patch
snowpatch_ozlabs/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
snowpatch_ozlabs/needsstable success Patch has no Fixes tags

Commit Message

nico.vince@gmail.com Sept. 23, 2020, 2:08 p.m. UTC
From: Nicolas VINCENT <nicolas.vincent@vossloh.com>

the i2c_ram structure is missing the sdmatmp field mentionned in
datasheet for MPC8272 at paragraph 36.5. With this field missing, the
hardware would write past the allocated memory done through
cpm_muram_alloc for the i2c_ram structure and land in memory allocated
for the buffers descriptors corrupting the cbd_bufaddr field. Since this
field is only set during setup(), the first i2c transaction would work
and the following would send data read from an arbitrary memory
location.

Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>
---
 drivers/i2c/busses/i2c-cpm.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Jochen Friedrich Sept. 23, 2020, 2:12 p.m. UTC | #1
Acked-by: Jochen Friedrich <jochen@scram.de>

Am 23.09.2020 um 16:08 schrieb nico.vince@gmail.com:
> From: Nicolas VINCENT <nicolas.vincent@vossloh.com>
> 
> the i2c_ram structure is missing the sdmatmp field mentionned in
> datasheet for MPC8272 at paragraph 36.5. With this field missing, the
> hardware would write past the allocated memory done through
> cpm_muram_alloc for the i2c_ram structure and land in memory allocated
> for the buffers descriptors corrupting the cbd_bufaddr field. Since this
> field is only set during setup(), the first i2c transaction would work
> and the following would send data read from an arbitrary memory
> location.
> 
> Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>
> ---
>   drivers/i2c/busses/i2c-cpm.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
> index 1213e1932ccb..24d584a1c9a7 100644
> --- a/drivers/i2c/busses/i2c-cpm.c
> +++ b/drivers/i2c/busses/i2c-cpm.c
> @@ -65,6 +65,9 @@ struct i2c_ram {
>   	char    res1[4];	/* Reserved */
>   	ushort  rpbase;		/* Relocation pointer */
>   	char    res2[2];	/* Reserved */
> +	/* The following elements are only for CPM2 */
> +	char    res3[4];	/* Reserved */
> +	uint    sdmatmp;	/* Internal */
>   };
>   
>   #define I2COM_START	0x80
>
Wolfram Sang Sept. 23, 2020, 4:08 p.m. UTC | #2
On Wed, Sep 23, 2020 at 04:08:40PM +0200, nico.vince@gmail.com wrote:
> From: Nicolas VINCENT <nicolas.vincent@vossloh.com>
> 
> the i2c_ram structure is missing the sdmatmp field mentionned in
> datasheet for MPC8272 at paragraph 36.5. With this field missing, the
> hardware would write past the allocated memory done through
> cpm_muram_alloc for the i2c_ram structure and land in memory allocated
> for the buffers descriptors corrupting the cbd_bufaddr field. Since this
> field is only set during setup(), the first i2c transaction would work
> and the following would send data read from an arbitrary memory
> location.
> 
> Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>

Thanks!

Is someone able to identify a Fixes: tag I could add?

> ---
>  drivers/i2c/busses/i2c-cpm.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
> index 1213e1932ccb..24d584a1c9a7 100644
> --- a/drivers/i2c/busses/i2c-cpm.c
> +++ b/drivers/i2c/busses/i2c-cpm.c
> @@ -65,6 +65,9 @@ struct i2c_ram {
>  	char    res1[4];	/* Reserved */
>  	ushort  rpbase;		/* Relocation pointer */
>  	char    res2[2];	/* Reserved */
> +	/* The following elements are only for CPM2 */
> +	char    res3[4];	/* Reserved */
> +	uint    sdmatmp;	/* Internal */
>  };
>  
>  #define I2COM_START	0x80
> -- 
> 2.17.1
>
Christophe Leroy Sept. 23, 2020, 6:27 p.m. UTC | #3
Le 23/09/2020 à 18:08, Wolfram Sang a écrit :
> On Wed, Sep 23, 2020 at 04:08:40PM +0200, nico.vince@gmail.com wrote:
>> From: Nicolas VINCENT <nicolas.vincent@vossloh.com>
>>
>> the i2c_ram structure is missing the sdmatmp field mentionned in
>> datasheet for MPC8272 at paragraph 36.5. With this field missing, the
>> hardware would write past the allocated memory done through
>> cpm_muram_alloc for the i2c_ram structure and land in memory allocated
>> for the buffers descriptors corrupting the cbd_bufaddr field. Since this
>> field is only set during setup(), the first i2c transaction would work
>> and the following would send data read from an arbitrary memory
>> location.
>>
>> Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>
> 
> Thanks!
> 
> Is someone able to identify a Fixes: tag I could add?

I'd suggest

Fixes: 61045dbe9d8d ("i2c: Add support for I2C bus on Freescale 
CPM1/CPM2 controllers")

Christophe

> 
>> ---
>>   drivers/i2c/busses/i2c-cpm.c | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
>> index 1213e1932ccb..24d584a1c9a7 100644
>> --- a/drivers/i2c/busses/i2c-cpm.c
>> +++ b/drivers/i2c/busses/i2c-cpm.c
>> @@ -65,6 +65,9 @@ struct i2c_ram {
>>   	char    res1[4];	/* Reserved */
>>   	ushort  rpbase;		/* Relocation pointer */
>>   	char    res2[2];	/* Reserved */
>> +	/* The following elements are only for CPM2 */
>> +	char    res3[4];	/* Reserved */
>> +	uint    sdmatmp;	/* Internal */
>>   };
>>   
>>   #define I2COM_START	0x80
>> -- 
>> 2.17.1
>>
Wolfram Sang Sept. 27, 2020, 1:15 p.m. UTC | #4
On Wed, Sep 23, 2020 at 04:08:40PM +0200, nico.vince@gmail.com wrote:
> From: Nicolas VINCENT <nicolas.vincent@vossloh.com>
> 
> the i2c_ram structure is missing the sdmatmp field mentionned in
> datasheet for MPC8272 at paragraph 36.5. With this field missing, the
> hardware would write past the allocated memory done through
> cpm_muram_alloc for the i2c_ram structure and land in memory allocated
> for the buffers descriptors corrupting the cbd_bufaddr field. Since this
> field is only set during setup(), the first i2c transaction would work
> and the following would send data read from an arbitrary memory
> location.
> 
> Signed-off-by: Nicolas VINCENT <nicolas.vincent@vossloh.com>

Fixes tag aded and applied to for-current, thanks everyone!
diff mbox series

Patch

diff --git a/drivers/i2c/busses/i2c-cpm.c b/drivers/i2c/busses/i2c-cpm.c
index 1213e1932ccb..24d584a1c9a7 100644
--- a/drivers/i2c/busses/i2c-cpm.c
+++ b/drivers/i2c/busses/i2c-cpm.c
@@ -65,6 +65,9 @@  struct i2c_ram {
 	char    res1[4];	/* Reserved */
 	ushort  rpbase;		/* Relocation pointer */
 	char    res2[2];	/* Reserved */
+	/* The following elements are only for CPM2 */
+	char    res3[4];	/* Reserved */
+	uint    sdmatmp;	/* Internal */
 };
 
 #define I2COM_START	0x80