[PATCH v5] 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.

Found by code review.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 86a18ee21e5e ("EDAC, ti: Add support for TI keystone and DRA7xx EDAC")
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202408160935.A6QFliqt-lkp@xxxxxxxxx/
Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
---
Changes in v5:
- According to the developer's suggestion, added an inspection of function 
of_translate_address(). However, kernel test robot reported a build 
warning, so the inspection is removed here, reverting to the modification 
solution of patch v3.
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 | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/edac/ti_edac.c b/drivers/edac/ti_edac.c
index 29723c9592f7..6f3da8d99eab 100644
--- a/drivers/edac/ti_edac.c
+++ b/drivers/edac/ti_edac.c
@@ -207,6 +207,9 @@ 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);
 
 	for_each_matching_node(np, ti_edac_of_match) {
@@ -214,6 +217,9 @@ static int _emif_get_id(struct device_node *node)
 			continue;
 
 		addrp = of_get_address(np, 0, NULL, NULL);
+		if (!addrp)
+			return -EINVAL;
+
 		addr = (u32)of_translate_address(np, addrp);
 
 		edac_printk(KERN_INFO, EDAC_MOD_NAME,
-- 
2.25.1