[PATCH] EDAC/altera: Fix possible null pointer dereference

[Ma Ke]

In altr_s10_sdram_check_ecc_deps(), of_get_address() may return NULL which
is later dereferenced. Fix this bug by adding NULL check.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: e1bca853dddc ("EDAC/altera: Add SDRAM ECC check for U-Boot")
Signed-off-by: Ma Ke <make24@xxxxxxxxxxx>
---
 drivers/edac/altera_edac.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/drivers/edac/altera_edac.c b/drivers/edac/altera_edac.c
index fe89f5c4837f..d6bf0eebeb41 100644
--- a/drivers/edac/altera_edac.c
+++ b/drivers/edac/altera_edac.c
@@ -1086,6 +1086,7 @@ static int altr_s10_sdram_check_ecc_deps(struct altr_edac_device_dev *device)
 	struct arm_smccc_res result;
 	struct device_node *np;
 	phys_addr_t sdram_addr;
+	const __be32 *sdram_addrp;
 	u32 read_reg;
 	int ret;
 
@@ -1093,8 +1094,14 @@ static int altr_s10_sdram_check_ecc_deps(struct altr_edac_device_dev *device)
 	if (!np)
 		goto sdram_err;
 
-	sdram_addr = of_translate_address(np, of_get_address(np, 0,
-							     NULL, NULL));
+	sdram_addrp = of_get_address(np, 0, NULL, NULL);
+	if (!sdram_addrp)
+		return -EINVAL;
+
+	sdram_addr = of_translate_address(np, sdram_addrp);
+	if (!sdram_addr)
+		return -EINVAL;
+
 	of_node_put(np);
 	sdram_ecc_addr = (unsigned long)sdram_addr + prv->ecc_en_ofst;
 	arm_smccc_smc(INTEL_SIP_SMC_REG_READ, sdram_ecc_addr,
-- 
2.25.1