scsi: storvsc: fix memory leak on ring buffer busy

[ Upstream commit 0208eeaa650c5c866a3242201678a19e6dc4a14e ]

When storvsc is sending I/O to Hyper-v, it may allocate a bigger buffer
descriptor for large data payload that can't fit into a pre-allocated
buffer descriptor. This bigger buffer is freed on return path.

If I/O request to Hyper-v fails due to ring buffer busy, the storvsc
allocated buffer descriptor should also be freed.

[mkp: applied by hand]

Fixes: be0cf6ca301c ("scsi: storvsc: Set the tablesize based on the information given by the host")
Cc: <stable@vger.kernel.org>
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 6c52d1411a73c0172aa35bbea6742acadbff1c16..51a0cc047b5f1f9dcbc520dadd7d4bb99dd2a84e 100644 (file)
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1699,6 +1699,8 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
        ret = storvsc_do_io(dev, cmd_request);
 
        if (ret == -EAGAIN) {
+               if (payload_sz > sizeof(cmd_request->mpb))
+                       kfree(payload);
                /* no more space */
 
                if (cmd_request->bounce_sgl_count)