releases/4.9.52/scsi-storvsc-fix-memory-leak-on-ring-buffer-busy.patch

   1 From 0208eeaa650c5c866a3242201678a19e6dc4a14e Mon Sep 17 00:00:00 2001
   2 From: Long Li <longli@microsoft.com>
   3 Date: Mon, 28 Aug 2017 17:43:59 -0700
   4 Subject: scsi: storvsc: fix memory leak on ring buffer busy
   5
   6 From: Long Li <longli@microsoft.com>
   7
   8 commit 0208eeaa650c5c866a3242201678a19e6dc4a14e upstream.
   9
  10 When storvsc is sending I/O to Hyper-v, it may allocate a bigger buffer
  11 descriptor for large data payload that can't fit into a pre-allocated
  12 buffer descriptor. This bigger buffer is freed on return path.
  13
  14 If I/O request to Hyper-v fails due to ring buffer busy, the storvsc
  15 allocated buffer descriptor should also be freed.
  16
  17 [mkp: applied by hand]
  18
  19 Fixes: be0cf6ca301c ("scsi: storvsc: Set the tablesize based on the information given by the host")
  20 Signed-off-by: Long Li <longli@microsoft.com>
  21 Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
  22 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  23
  24 ---
  25  drivers/scsi/storvsc_drv.c |    2 ++
  26  1 file changed, 2 insertions(+)
  27
  28 --- a/drivers/scsi/storvsc_drv.c
  29 +++ b/drivers/scsi/storvsc_drv.c
  30 @@ -1559,6 +1559,8 @@ static int storvsc_queuecommand(struct S
  31         ret = storvsc_do_io(dev, cmd_request);
  32
  33         if (ret == -EAGAIN) {
  34 +               if (payload_sz > sizeof(cmd_request->mpb))
  35 +                       kfree(payload);
  36                 /* no more space */
  37                 return SCSI_MLQUEUE_DEVICE_BUSY;
  38         }