commit f73af205e63f3fc74c55c73a33790f869898204c
author Mark Kettenis <kettenis@openbsd.org> Thu Jun 05 16:40:45 2025 +0200
committer Sven Peter <sven@svenpeter.dev> Sat Jun 07 09:58:50 2025 +0200
tree daf8263fa6c9d18c92b164bc0b441ef12ff05777
parent dca94dcb2be8091b7ad98c0d15c10f35e43a0c52

payload: Fix running payloads in stage1

Don't attempt to modify string constants which live in read-only
memory.

Fixes: 75329c5 ("payload: Fix m1n1 stage 1 version passing")
Signed-off-by: Mark Kettenis <kettenis@openbsd.org>

src/payload.c

diff --git a/src/payload.c b/src/payload.c
index 9f3575c..5b1547f 100644
--- a/src/payload.c
+++ b/src/payload.c
@@ -333,10 +333,12 @@
 
         for (size_t i = 0; i < chosen_cnt; i++) {
             char *val = memchr(chosen[i], '=', MAX_VAR_NAME + 1);
+            char var[MAX_VAR_NAME + 1];
 
             assert(val);
-            val[0] = 0; // Terminate var name
-            if (kboot_set_chosen(chosen[i] + 7, val + 1) < 0)
+            memcpy(var, chosen[i], val - chosen[i]);
+            var[val - chosen[i]] = 0; // Terminate var name
+            if (kboot_set_chosen(var + 7, val + 1) < 0)
                 printf("Failed to kboot set %s='%s'\n", chosen[i], val);
         }