MIPS: fw: Allow firmware to pass a empty env

commit ee1809ed7bc456a72dc8410b475b73021a3a68d5 upstream. fw_getenv will use env entry to determine style of env, however it is legal for firmware to just pass a empty list. Check if first entry exist before running strchr to avoid null pointer dereference. Cc: [email protected] Link: clbr/n64bootloader#5 Signed-off-by: Jiaxun Yang <[email protected]> Signed-off-by: Thomas Bogendoerfer <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> Signed-off-by: Ulrich Hecht <[email protected]>
Amy07i · Jun 6, 2023 · 6d28e13 · 6d28e13
1 parent b88a60a
commit 6d28e13
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/arch/mips/fw/lib/cmdline.c b/arch/mips/fw/lib/cmdline.c
@@ -51,7 +51,7 @@ char *fw_getenv(char *envname)
 {
 	char *result = NULL;
 
-	if (_fw_envp != NULL) {
+	if (_fw_envp != NULL && fw_envp(0) != NULL) {
 		/*
 		 * Return a pointer to the given environment variable.
 		 * YAMON uses "name", "value" pairs, while U-Boot uses