[PATCH v4] EDAC/ti: Fix possible null pointer dereference in _emif_get_id()

[Ma Ke]

In _emif_get_id(), of_get_address() may return NULL which is later
dereferenced. Fix this bug by adding NULL check. of_translate_address() is
the same.

Found by code review.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 86a18ee21e5e ("EDAC, ti: Add support for TI keystone and DRA7xx EDAC")
Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
---
Changes in v4:
- added the check of of_translate_address() as suggestions.
Changes in v3:
- added the patch operations omitted in PATCH v2 RESEND compared to PATCH 
v2. Sorry for my oversight.
Changes in v2:
- added Cc stable line.
---
 drivers/edac/ti_edac.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/edac/ti_edac.c b/drivers/edac/ti_edac.c
index 29723c9592f7..f466f12630d3 100644
--- a/drivers/edac/ti_edac.c
+++ b/drivers/edac/ti_edac.c
@@ -207,14 +207,24 @@ static int _emif_get_id(struct device_node *node)
 	int my_id = 0;
 
 	addrp = of_get_address(node, 0, NULL, NULL);
+	if (!addrp)
+		return -EINVAL;
+
 	my_addr = (u32)of_translate_address(node, addrp);
+	if (my_addr == OF_BAD_ADDR)
+		return -EINVAL;
 
 	for_each_matching_node(np, ti_edac_of_match) {
 		if (np == node)
 			continue;
 
 		addrp = of_get_address(np, 0, NULL, NULL);
+		if (!addrp)
+			return -EINVAL;
+
 		addr = (u32)of_translate_address(np, addrp);
+		if (addr == OF_BAD_ADDR)
+			return -EINVAL;
 
 		edac_printk(KERN_INFO, EDAC_MOD_NAME,
 			    "addr=%x, my_addr=%x\n",
-- 
2.25.1