Re: [PATCH v2 3/7] dmaengine: idxd: fix memory leak in error handling path of idxd_setup_groups

[Shuai Xue <xueshuai@linux.alibaba.com>]

在 2025/2/19 04:20, Fenghua Yu 写道:
> Hi, Shuai,
> 
> On 2/14/25 21:44, Shuai Xue wrote:
>> Memory allocated for groups is not freed if an error occurs during
>> idxd_setup_groups(). To fix it, free the allocated memory in the reverse
>> order of allocation before exiting the function in case of an error.
>>
>> Fixes: defe49f96012 ("dmaengine: idxd: fix group conf_dev lifetime")
>> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>   drivers/dma/idxd/init.c | 4 ++++
>>   1 file changed, 4 insertions(+)
>>
>> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
>> index 4e47075c5bef..a2da68e6144d 100644
>> --- a/drivers/dma/idxd/init.c
>> +++ b/drivers/dma/idxd/init.c
>> @@ -328,6 +328,7 @@ static int idxd_setup_groups(struct idxd_device *idxd)
>>           rc = dev_set_name(conf_dev, "group%d.%d", idxd->id, group->id);
>>           if (rc < 0) {
>>               put_device(conf_dev);
>> +            kfree(group);
>>               goto err;
>>           }
>> @@ -352,7 +353,10 @@ static int idxd_setup_groups(struct idxd_device *idxd)
>>       while (--i >= 0) {
>>           group = idxd->groups[i];
>>           put_device(group_confdev(group));
>> +        kfree(group);
>>       }
>> +    kfree(idxd->groups);
>> +
> 
> What happens to the memory areas previously allocated for wqs and engines after idxd_setup_groups() fails? They need to be freed as well, but currently they are not.
> 
> Maybe a separate patch cleans up the previously allocated mem areas for wqs/engines/groups if there is any failure after the allocations?
> 

Agreed, will add a new patch to fix it.

Thanks
Shuai