Merge tag 'dmaengine-fix-5.5-rc5' of git://git.infradead.org/users/vkoul/slave-dma

Pull dmaengine fixes from Vinod Koul:
 "A bunch of fixes for:

   - uninitialized dma_slave_caps access

   - virt-dma use after free in vchan_complete()

   - driver fixes for ioat, k3dma and jz4780"

* tag 'dmaengine-fix-5.5-rc5' of git://git.infradead.org/users/vkoul/slave-dma:
  ioat: ioat_alloc_ring() failure handling.
  dmaengine: virt-dma: Fix access after free in vchan_complete()
  dmaengine: k3dma: Avoid null pointer traversal
  dmaengine: dma-jz4780: Also break descriptor chains on JZ4725B
  dmaengine: Fix access to uninitialized dma_slave_caps

Author: torvalds

drivers/dma/dma-jz4780.c

@@ -999,7 +999,8 @@ static const struct jz4780_dma_soc_data jz4740_dma_soc_data = {
 static const struct jz4780_dma_soc_data jz4725b_dma_soc_data = {
 	.nb_channels = 6,
 	.transfer_ord_max = 5,
-	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC,
+	.flags = JZ_SOC_DATA_PER_CHAN_PM | JZ_SOC_DATA_NO_DCKES_DCKEC |
+		 JZ_SOC_DATA_BREAK_LINKS,
 };
 
 static const struct jz4780_dma_soc_data jz4770_dma_soc_data = {

drivers/dma/ioat/dma.c

@@ -377,10 +377,11 @@ ioat_alloc_ring(struct dma_chan *c, int order, gfp_t flags)
 
 		descs->virt = dma_alloc_coherent(to_dev(ioat_chan),
 						 SZ_2M, &descs->hw, flags);
-		if (!descs->virt && (i > 0)) {
+		if (!descs->virt) {
 			int idx;
 
 			for (idx = 0; idx < i; idx++) {
+				descs = &ioat_chan->descs[idx];
 				dma_free_coherent(to_dev(ioat_chan), SZ_2M,
 						  descs->virt, descs->hw);
 				descs->virt = NULL;

drivers/dma/k3dma.c

@@ -229,9 +229,11 @@ static irqreturn_t k3_dma_int_handler(int irq, void *dev_id)
 			c = p->vchan;
 			if (c && (tc1 & BIT(i))) {
 				spin_lock_irqsave(&c->vc.lock, flags);
-				vchan_cookie_complete(&p->ds_run->vd);
-				p->ds_done = p->ds_run;
-				p->ds_run = NULL;
+				if (p->ds_run != NULL) {
+					vchan_cookie_complete(&p->ds_run->vd);
+					p->ds_done = p->ds_run;
+					p->ds_run = NULL;
+				}
 				spin_unlock_irqrestore(&c->vc.lock, flags);
 			}
 			if (c && (tc2 & BIT(i))) {
@@ -271,6 +273,10 @@ static int k3_dma_start_txd(struct k3_dma_chan *c)
 	if (BIT(c->phy->idx) & k3_dma_get_chan_stat(d))
 		return -EAGAIN;
 
+	/* Avoid losing track of  ds_run if a transaction is in flight */
+	if (c->phy->ds_run)
+		return -EAGAIN;
+
 	if (vd) {
 		struct k3_dma_desc_sw *ds =
 			container_of(vd, struct k3_dma_desc_sw, vd);

drivers/dma/virt-dma.c

@@ -104,9 +104,8 @@ static void vchan_complete(unsigned long arg)
 		dmaengine_desc_get_callback(&vd->tx, &cb);
 
 		list_del(&vd->node);
-		vchan_vdesc_fini(vd);
-
 		dmaengine_desc_callback_invoke(&cb, &vd->tx_result);
+		vchan_vdesc_fini(vd);
 	}
 }
 

include/linux/dmaengine.h

@@ -1364,8 +1364,11 @@ static inline int dma_get_slave_caps(struct dma_chan *chan,
 static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx)
 {
 	struct dma_slave_caps caps;
+	int ret;
 
-	dma_get_slave_caps(tx->chan, &caps);
+	ret = dma_get_slave_caps(tx->chan, &caps);
+	if (ret)
+		return ret;
 
 	if (caps.descriptor_reuse) {
 		tx->flags |= DMA_CTRL_REUSE;