udev: Fix SIGSEGV in AlternativeNamesPolicy handling

The function sd_device_get_property_value has some paths where it exits without
touching the n pointer. In those cases, n remained uninitialized until it was
eventually read inside isempty where it caused the segmentation fault.

Fixes #15078

diff --git a/src/udev/net/link-config.c b/src/udev/net/link-config.c
index 71946c9ecc75e50c5d9821d68071ab2fdb5ed043..48039511fa69bc5d778f30e7c1f1cfa1c364cad7 100644 (file)
--- a/src/udev/net/link-config.c
+++ b/src/udev/net/link-config.c
@@ -498,7 +498,7 @@ int link_config_apply(link_config_ctx *ctx, link_config *config,
 
         if (config->alternative_names_policy)
                 for (NamePolicy *p = config->alternative_names_policy; *p != _NAMEPOLICY_INVALID; p++) {
-                        const char *n;
+                        const char *n = NULL;
 
                         switch (*p) {
                         case NAMEPOLICY_DATABASE: