Patch "dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly" has been added to the 4.9-stable tree

Patch "dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly" 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

    dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

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:
     dmaengine-mv_xor_v2-handle-mv_xor_v2_prep_sw_desc-error-properly.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 eb8df543e444492328f506adffc7dfe94111f1bd Mon Sep 17 00:00:00 2001
From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Date: Fri, 5 May 2017 11:57:44 +0200
Subject: dmaengine: mv_xor_v2: handle mv_xor_v2_prep_sw_desc() error properly

From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

commit eb8df543e444492328f506adffc7dfe94111f1bd upstream.

The mv_xor_v2_prep_sw_desc() is called from a few different places in
the driver, but we never take into account the fact that it might
return NULL. This commit fixes that, ensuring that we don't panic if
there are no more descriptors available.

Fixes: 19a340b1a820 ("dmaengine: mv_xor_v2: new driver")
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/dma/mv_xor_v2.c |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/drivers/dma/mv_xor_v2.c
+++ b/drivers/dma/mv_xor_v2.c
@@ -389,6 +389,8 @@ mv_xor_v2_prep_dma_memcpy(struct dma_cha
 		__func__, len, &src, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 
@@ -443,6 +445,8 @@ mv_xor_v2_prep_dma_xor(struct dma_chan *
 		__func__, src_cnt, len, &dest, flags);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	sw_desc->async_tx.flags = flags;
 
@@ -491,6 +495,8 @@ mv_xor_v2_prep_dma_interrupt(struct dma_
 		container_of(chan, struct mv_xor_v2_device, dmachan);
 
 	sw_desc = mv_xor_v2_prep_sw_desc(xor_dev);
+	if (!sw_desc)
+		return NULL;
 
 	/* set the HW descriptor */
 	hw_descriptor = &sw_desc->hw_desc;


Patches currently in stable-queue which might be from thomas.petazzoni@free-electrons.com are

queue-4.9/dmaengine-mv_xor_v2-properly-handle-wrapping-in-the-array-of-hw-descriptors.patch
queue-4.9/dmaengine-mv_xor_v2-enable-xor-engine-after-its-configuration.patch
queue-4.9/dmaengine-mv_xor_v2-set-dma-mask-to-40-bits.patch
queue-4.9/dmaengine-mv_xor_v2-do-not-use-descriptors-not-acked-by-async_tx.patch
queue-4.9/dmaengine-mv_xor_v2-handle-mv_xor_v2_prep_sw_desc-error-properly.patch
queue-4.9/dmaengine-mv_xor_v2-remove-interrupt-coalescing.patch
queue-4.9/dmaengine-mv_xor_v2-fix-tx_submit-implementation.patch