[PATCH v2] insert-sys-cert: fix use of uninitialized pointer with an empty System.map

[Leizhen Zhang <lzsx618@gmail.com>]

get_symbol_from_map() only assigns n inside the loop that reads the
System.map file. If the file is empty, the loop body never runs and n is
then tested while uninitialized, as reported by MemorySanitizer.

Initialize n to NULL.

Fixes: c4c361059585 ("KEYS: Reserve an extra certificate symbol for inserting without recompiling")
Assisted-by: Claude:claude-opus-5-5 MSan
Signed-off-by: Leizhen Zhang <lzsx618@gmail.com>
---
v2:
 - Use my real name in the From and Signed-off-by lines. No code
   changes.

v1: https://lore.kernel.org/r/20261005104217.1788155-1-lzsx618@gmail.com

 scripts/insert-sys-cert.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/scripts/insert-sys-cert.c b/scripts/insert-sys-cert.c
index 8902836c23..e0bf0afc1b 100644
--- a/scripts/insert-sys-cert.c
+++ b/scripts/insert-sys-cert.c
@@ -94,7 +94,7 @@ static void get_symbol_from_map(Elf_Ehdr *hdr, FILE *f, char *name,
 				struct sym *s)
 {
 	char l[LINE_SIZE];
-	char *w, *p, *n;
+	char *w, *p, *n = NULL;
 
 	s->size = 0;
 	s->address = 0;
-- 
2.34.1