Re: [PATCH] scsi: storvsc: Fix storvsc_queuecommand() memory leak

[Tianyu Lan <ltykernel@gmail.com>]

On 1/9/2022 8:17 AM, Juan Vazquez wrote:
> Fix possible memory leak in error path of storvsc_queuecommand() when
> DMA mapping fails.
> 
> Fixes: 743b237c3a7b ("scsi: storvsc: Add Isolation VM support for storvsc driver")
> Signed-off-by: Juan Vazquez <juvazq@linux.microsoft.com>

Looks good. Thanks for the fix patch.

Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>

> ---
>   drivers/scsi/storvsc_drv.c | 17 ++++++++++++-----
>   1 file changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
> index 2273b843d9d2..9a0bba5a51a7 100644
> --- a/drivers/scsi/storvsc_drv.c
> +++ b/drivers/scsi/storvsc_drv.c
> @@ -1850,8 +1850,10 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
>   		payload->range.offset = offset_in_hvpg;
>   
>   		sg_count = scsi_dma_map(scmnd);
> -		if (sg_count < 0)
> -			return SCSI_MLQUEUE_DEVICE_BUSY;
> +		if (sg_count < 0) {
> +			ret = SCSI_MLQUEUE_DEVICE_BUSY;
> +			goto err_free_payload;
> +		}
>   
>   		for_each_sg(sgl, sg, sg_count, j) {
>   			/*
> @@ -1886,13 +1888,18 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
>   	put_cpu();
>   
>   	if (ret == -EAGAIN) {
> -		if (payload_sz > sizeof(cmd_request->mpb))
> -			kfree(payload);
>   		/* no more space */
> -		return SCSI_MLQUEUE_DEVICE_BUSY;
> +		ret = SCSI_MLQUEUE_DEVICE_BUSY;
> +		goto err_free_payload;
>   	}
>   
>   	return 0;
> +
> +err_free_payload:
> +	if (payload_sz > sizeof(cmd_request->mpb))
> +		kfree(payload);
> +
> +	return ret;
>   }
>   
>   static struct scsi_host_template scsi_driver = {