[PATCH v4 02/17] dmaengine: sh: rz-dmac: Fix incorrect NULL check on list_first_entry()

[Claudiu]

From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>

The list passed as argument to list_first_entry() is expected to be not
empty. Use list_first_entry_or_null() to avoid dereferencing invalid
memory.

Fixes: 21323b118c16 ("dmaengine: sh: rz-dmac: Add device_tx_status() callback")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
---

Changes in v4:
- none, this patch is new

 drivers/dma/sh/rz-dmac.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/sh/rz-dmac.c b/drivers/dma/sh/rz-dmac.c
index 9f206a33dcc6..6d80cb668957 100644
--- a/drivers/dma/sh/rz-dmac.c
+++ b/drivers/dma/sh/rz-dmac.c
@@ -723,8 +723,8 @@ static u32 rz_dmac_chan_get_residue(struct rz_dmac_chan *channel,
 	u32 crla, crtb, i;
 
 	/* Get current processing virtual descriptor */
-	current_desc = list_first_entry(&channel->ld_active,
-					struct rz_dmac_desc, node);
+	current_desc = list_first_entry_or_null(&channel->ld_active,
+						struct rz_dmac_desc, node);
 	if (!current_desc)
 		return 0;
 
-- 
2.43.0