Re: [PATCH v2 1/7] dmaengine: idxd: fix memory leak in error handling path of idxd_setup_wqs()

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

在 2025/2/15 19:00, Markus Elfring 写道:
>> Memory allocated for wqs is not freed if an error occurs during
>> idxd_setup_wqs(). To fix it, free the allocated memory in the reverse
>> order of allocation before exiting the function in case of an error.
>>
>> Fixes: a8563a33a5e2 ("dmanegine: idxd: reformat opcap output to match bitmap_parse() input")
> …
> 
> Will a “stable tag” become relevant also for this patch series?
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/process/stable-kernel-rules.rst?h=v6.14-rc2#n3
> 

I don't know if this is a real serious issue for stable kernel.
But I would like to add stable tag if the mantainer @Vinicius and @Dave ask.

> 
>> +++ b/drivers/dma/idxd/init.c
>> @@ -169,8 +169,8 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
> …
>> @@ -204,6 +205,7 @@ static int idxd_setup_wqs(struct idxd_device *idxd)
>>   		wq->wqcfg = kzalloc_node(idxd->wqcfg_size, GFP_KERNEL, dev_to_node(dev));
>>   		if (!wq->wqcfg) {
>>   			put_device(conf_dev);
>> +			kfree(wq);
>>   			rc = -ENOMEM;
>>   			goto err;
>>   		}
> …
> 
> I got the impression that more common exception handling code could be moved
> to additional jump targets at the end of such function implementations.
> Will further adjustment opportunities be taken into account for
> the affected resource management?

Sure, I will move them to the jump targets.

> 
> Regards,
> Markus

Thanks for valuable comments.
Shuai