Re: [PATCH v2 5/7] dmaengine: idxd: fix memory leak in error handling path of idxd_pci_probe

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

在 2025/2/19 04:21, Fenghua Yu 写道:
> Hi, Shuai,
> 
> On 2/14/25 21:44, Shuai Xue wrote:
>> Memory allocated for idxd is not freed if an error occurs during
>> idxd_pci_probe(). To fix it, free the allocated memory in the reverse
>> order of allocation before exiting the function in case of an error.
>>
>> Fixes: bfe1d56091c1 ("dmaengine: idxd: Init and probe for Intel data accelerators")
>> Signed-off-by: Shuai Xue <xueshuai@linux.alibaba.com>
>> Reviewed-by: Dave Jiang <dave.jiang@intel.com>
>> ---
>>   drivers/dma/idxd/init.c | 10 +++++++++-
>>   1 file changed, 9 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
>> index dc34830fe7c3..ac1cdc1d82bf 100644
>> --- a/drivers/dma/idxd/init.c
>> +++ b/drivers/dma/idxd/init.c
>> @@ -550,6 +550,14 @@ static void idxd_read_caps(struct idxd_device *idxd)
>>           idxd->hw.iaa_cap.bits = ioread64(idxd->reg_base + IDXD_IAACAP_OFFSET);
>>   }
>> +static void idxd_free(struct idxd_device *idxd)
>> +{
>> +    put_device(idxd_confdev(idxd));
>> +    bitmap_free(idxd->opcap_bmap);
>> +    ida_free(&idxd_ida, idxd->id);
>> +    kfree(idxd);
> 
> opcap_bmap, idxd_ida, idxd are NOT allocated during FLR re-init idxd device. In the FLR case, they should not be freed.
> 

After relook the code, idxd_free() will not be called in FLR case,
because all error lable in idxd_pci_probe_alloc() is called from
alloc_idxd=true, not the FLR case.

Anyway, I will add a protection in idxd_free().

Thanks.
Shuai