[PATCH 4.4 45/66] scsi: storvsc: fix memory leak on ring buffer busy

Greg Kroah-Hartman
2017-09-24T20:35:40Z

From: Long Li <longli@microsoft.com>

commit 0208eeaa650c5c866a3242201678a19e6dc4a14e upstream.

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")
Signed-off-by: Long Li <longli@microsoft.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/scsi/storvsc_drv.c | 2 ++
1 file changed, 2 insertions(+)

--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1511,6 +1511,8 @@ static int storvsc_queuecommand(struct S
ret = storvsc_do_io(dev, cmd_request);

if (ret == -EAGAIN) {
+ if (payload_sz > sizeof(cmd_request->mpb))
+ kfree(payload);
/* no more space */
return SCSI_MLQUEUE_DEVICE_BUSY;
}