[PATCH] ARM: mvebu: validate memory node device_type strings

[Pengpeng Hou]

mvebu_scan_mem() fetches the raw device_type property and immediately
compares it with strcmp(). Flat DT properties are external boot input,
and this path does not prove that the property is NUL-terminated within
its declared bounds.

Use fdt_stringlist_get() so malformed unterminated device_type
properties are rejected before they are used as C strings.

Signed-off-by: Pengpeng Hou <pengpeng@xxxxxxxxxxx>
---
 arch/arm/mach-mvebu/board-v7.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/arch/arm/mach-mvebu/board-v7.c b/arch/arm/mach-mvebu/board-v7.c
index a0740ab0dca9..f867f6233108 100644
--- a/arch/arm/mach-mvebu/board-v7.c
+++ b/arch/arm/mach-mvebu/board-v7.c
@@ -11,6 +11,7 @@
 
 #include <linux/kernel.h>
 #include <linux/init.h>
+#include <linux/libfdt.h>
 #include <linux/of_address.h>
 #include <linux/of_fdt.h>
 #include <linux/io.h>
@@ -66,7 +67,8 @@ void __iomem *mvebu_get_scu_base(void)
 static int __init mvebu_scan_mem(unsigned long node, const char *uname,
 				 int depth, void *data)
 {
-	const char *type = of_get_flat_dt_prop(node, "device_type", NULL);
+	const char *type = fdt_stringlist_get(initial_boot_params, node,
+					      "device_type", 0, NULL);
 	const __be32 *reg, *endp;
 	int l;
 
-- 
2.50.1 (Apple Git-155)