From: Tobias Stoeckmann <tobias@stoeckmann.org>
Date: Fri, 18 Oct 2024 15:37:40 +0000 (+0200)
Subject: depmod: Prevent undefined behavior
X-Git-Tag: v34~199
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d056ac221b2b944307b561bbfc35e5fb3f782e1d;p=thirdparty%2Fkmod.git

depmod: Prevent undefined behavior

Calling qsort with NULL argument is invalid, although size 0 would
prevent anything bad from happening. Make sure that UBSAN is not
triggered.

Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
Reviewed-by: Emil Velikov <emil.l.velikov@gmail.com>
Link: https://github.com/kmod-project/kmod/pull/193
Signed-off-by: Lucas De Marchi <lucas.de.marchi@gmail.com>
---

diff --git a/tools/depmod.c b/tools/depmod.c
index 3328103e..42cc0a21 100644
--- a/tools/depmod.c
+++ b/tools/depmod.c
@@ -1494,10 +1494,12 @@ static void depmod_modules_sort(struct depmod *depmod)
 		mod->sort_idx = i++;
 	}
 
-	array_sort(&depmod->modules, mod_cmp);
-	for (idx = 0; idx < depmod->modules.count; idx++) {
-		struct mod *m = depmod->modules.array[idx];
-		m->idx = idx;
+	if (depmod->modules.count > 1) {
+		array_sort(&depmod->modules, mod_cmp);
+		for (idx = 0; idx < depmod->modules.count; idx++) {
+			struct mod *m = depmod->modules.array[idx];
+			m->idx = idx;
+		}
 	}
 
 corrupted: