Patch "RDMA/qib,hfi1: Fix MR reference count leak on write with immediate" has been added to the 4.9-stable tree

Patch "RDMA/qib,hfi1: Fix MR reference count leak on write with immediate" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    RDMA/qib,hfi1: Fix MR reference count leak on write with immediate

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     rdma-qib-hfi1-fix-mr-reference-count-leak-on-write-with-immediate.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 1feb40067cf04ae48d65f728d62ca255c9449178 Mon Sep 17 00:00:00 2001
From: Mike Marciniszyn <mike.marciniszyn@intel.com>
Date: Fri, 12 May 2017 09:02:00 -0700
Subject: RDMA/qib,hfi1: Fix MR reference count leak on write with immediate

From: Mike Marciniszyn <mike.marciniszyn@intel.com>

commit 1feb40067cf04ae48d65f728d62ca255c9449178 upstream.

The handling of IB_RDMA_WRITE_ONLY_WITH_IMMEDIATE will leak a memory
reference when a buffer cannot be allocated for returning the immediate
data.

The issue is that the rkey validation has already occurred and the RNR
nak fails to release the reference that was fruitlessly gotten.  The
the peer will send the identical single packet request when its RNR
timer pops.

The fix is to release the held reference prior to the rnr nak exit.
This is the only sequence the requires both rkey validation and the
buffer allocation on the same packet.

Tested-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/infiniband/hw/hfi1/rc.c    |    5 ++++-
 drivers/infiniband/hw/qib/qib_rc.c |    4 +++-
 2 files changed, 7 insertions(+), 2 deletions(-)

--- a/drivers/infiniband/hw/hfi1/rc.c
+++ b/drivers/infiniband/hw/hfi1/rc.c
@@ -2366,8 +2366,11 @@ send_last:
 		ret = hfi1_rvt_get_rwqe(qp, 1);
 		if (ret < 0)
 			goto nack_op_err;
-		if (!ret)
+		if (!ret) {
+			/* peer will send again */
+			rvt_put_ss(&qp->r_sge);
 			goto rnr_nak;
+		}
 		wc.ex.imm_data = ohdr->u.rc.imm_data;
 		wc.wc_flags = IB_WC_WITH_IMM;
 		goto send_last;
--- a/drivers/infiniband/hw/qib/qib_rc.c
+++ b/drivers/infiniband/hw/qib/qib_rc.c
@@ -2067,8 +2067,10 @@ send_last:
 		ret = qib_get_rwqe(qp, 1);
 		if (ret < 0)
 			goto nack_op_err;
-		if (!ret)
+		if (!ret) {
+			rvt_put_ss(&qp->r_sge);
 			goto rnr_nak;
+		}
 		wc.ex.imm_data = ohdr->u.rc.imm_data;
 		hdrsize += 4;
 		wc.wc_flags = IB_WC_WITH_IMM;


Patches currently in stable-queue which might be from mike.marciniszyn@intel.com are

queue-4.9/rdma-qib-hfi1-fix-mr-reference-count-leak-on-write-with-immediate.patch