diff mbox series

[1/4] drm/amdgpu: fix a signedness bug in __verify_ras_table_checksum()

Message ID YOAsdyWeZAHF0oll@mwanda (mailing list archive)
State New, archived
Headers show
Series [1/4] drm/amdgpu: fix a signedness bug in __verify_ras_table_checksum() | expand

Commit Message

Dan Carpenter July 3, 2021, 9:44 a.m. UTC
If amdgpu_eeprom_read() returns a negative error code then the error
handling checks:

	if (res < buf_size) {

The problem is that "buf_size" is a u32 so negative values are type
promoted to a high positive values and the condition is false.  Fix
this by changing the type of "buf_size" to int.

Fixes: 79beb6114014 ("drm/amdgpu: Optimize EEPROM RAS table I/O")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
---
It's hard for me to tell the exact upper bound that "buf_size" can be,
but if it's over USHRT_MAX then we are well toasted.

 drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

Comments

Luben Tuikov July 4, 2021, 3:18 p.m. UTC | #1
Series is,
Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>

Regards,
Luben

On 2021-07-03 5:44 a.m., Dan Carpenter wrote:
> If amdgpu_eeprom_read() returns a negative error code then the error
> handling checks:
>
> 	if (res < buf_size) {
>
> The problem is that "buf_size" is a u32 so negative values are type
> promoted to a high positive values and the condition is false.  Fix
> this by changing the type of "buf_size" to int.
>
> Fixes: 79beb6114014 ("drm/amdgpu: Optimize EEPROM RAS table I/O")
> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
> ---
> It's hard for me to tell the exact upper bound that "buf_size" can be,
> but if it's over USHRT_MAX then we are well toasted.
>
>  drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
> index fc70620369e4..f07a456506ef 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
> @@ -978,9 +978,8 @@ const struct file_operations amdgpu_ras_debugfs_eeprom_table_ops = {
>  static int __verify_ras_table_checksum(struct amdgpu_ras_eeprom_control *control)
>  {
>  	struct amdgpu_device *adev = to_amdgpu_device(control);
> -	int res;
> +	int buf_size, res;
>  	u8  csum, *buf, *pp;
> -	u32 buf_size;
>  
>  	buf_size = RAS_TABLE_HEADER_SIZE +
>  		control->ras_num_recs * RAS_TABLE_RECORD_SIZE;
Luben Tuikov July 6, 2021, 12:52 a.m. UTC | #2
Alex,

I think we should pull these through amd-staging-drm-next.

Regards,
Luben

On 2021-07-04 11:18 a.m., Luben Tuikov wrote:
> Series is,
> Reviewed-by: Luben Tuikov <luben.tuikov@amd.com>
>
> Regards,
> Luben
>
> On 2021-07-03 5:44 a.m., Dan Carpenter wrote:
>> If amdgpu_eeprom_read() returns a negative error code then the error
>> handling checks:
>>
>> 	if (res < buf_size) {
>>
>> The problem is that "buf_size" is a u32 so negative values are type
>> promoted to a high positive values and the condition is false.  Fix
>> this by changing the type of "buf_size" to int.
>>
>> Fixes: 79beb6114014 ("drm/amdgpu: Optimize EEPROM RAS table I/O")
>> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
>> ---
>> It's hard for me to tell the exact upper bound that "buf_size" can be,
>> but if it's over USHRT_MAX then we are well toasted.
>>
>>  drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c | 3 +--
>>  1 file changed, 1 insertion(+), 2 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
>> index fc70620369e4..f07a456506ef 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
>> @@ -978,9 +978,8 @@ const struct file_operations amdgpu_ras_debugfs_eeprom_table_ops = {
>>  static int __verify_ras_table_checksum(struct amdgpu_ras_eeprom_control *control)
>>  {
>>  	struct amdgpu_device *adev = to_amdgpu_device(control);
>> -	int res;
>> +	int buf_size, res;
>>  	u8  csum, *buf, *pp;
>> -	u32 buf_size;
>>  
>>  	buf_size = RAS_TABLE_HEADER_SIZE +
>>  		control->ras_num_recs * RAS_TABLE_RECORD_SIZE;
diff mbox series

Patch

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
index fc70620369e4..f07a456506ef 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
@@ -978,9 +978,8 @@  const struct file_operations amdgpu_ras_debugfs_eeprom_table_ops = {
 static int __verify_ras_table_checksum(struct amdgpu_ras_eeprom_control *control)
 {
 	struct amdgpu_device *adev = to_amdgpu_device(control);
-	int res;
+	int buf_size, res;
 	u8  csum, *buf, *pp;
-	u32 buf_size;
 
 	buf_size = RAS_TABLE_HEADER_SIZE +
 		control->ras_num_recs * RAS_TABLE_RECORD_SIZE;