From: Luca Boccassi <luca.boccassi@gmail.com>
Date: Fri, 6 Mar 2026 20:25:05 +0000 (+0000)
Subject: udev: ensure tag parsing stays within bounds
X-Git-Tag: v260-rc3~20^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=45a200cd751fae382f4145760cf84fd181db1319;p=thirdparty%2Fsystemd.git

udev: ensure tag parsing stays within bounds

This cannot actually happen, but add a safety check nonetheless.

Reported on yeswehack.com as:
YWH-PGM9780-43

Follow-up for d7867b31836173d1a943ecb1cab6484536126411
---

diff --git a/src/udev/udev-builtin-path_id.c b/src/udev/udev-builtin-path_id.c
index 4db20e4a13f..cdd8da3203f 100644
--- a/src/udev/udev-builtin-path_id.c
+++ b/src/udev/udev-builtin-path_id.c
@@ -654,7 +654,7 @@ static void add_id_tag(UdevEvent *event, const char *path) {
         size_t i = 0;
 
         /* compose valid udev tag name */
-        for (const char *p = path; *p; p++) {
+        for (const char *p = path; *p && i < sizeof(tag) - 1; p++) {
                 if (ascii_isdigit(*p) ||
                     ascii_isalpha(*p) ||
                     *p == '-') {