From 3429ae7b2f02a4a6ad40d36ee06641d433d75a1b Mon Sep 17 00:00:00 2001 From: Armin Wolf Date: Wed, 10 Jun 2026 22:34:53 +0200 Subject: modpost: Handle malformed WMI GUID strings MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Some WMI GUIDs found inside binary MOF files contain both uppercase and lowercase characters. Blindly copying such GUIDs will prevent the associated WMI driver from loading automatically because the WMI GUID found inside WMI device ids always contains uppercase characters. Avoid this issue by always converting WMI GUID strings to uppercase. Also verify that the WMI GUID string actually looks like a valid GUID. Signed-off-by: Armin Wolf Reviewed-by: Mario Limonciello Link: https://patch.msgid.link/20260610203453.816254-10-W_Armin@gmx.de Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- scripts/mod/file2alias.c | 28 +++++++++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'scripts/mod') diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index 4e99393a35f1..20e542a888c4 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -1253,6 +1253,8 @@ static void do_tee_entry(struct module *mod, void *symval) static void do_wmi_entry(struct module *mod, void *symval) { DEF_FIELD_ADDR(symval, wmi_device_id, guid_string); + char result[sizeof(*guid_string)]; + int i; if (strlen(*guid_string) != UUID_STRING_LEN) { warn("Invalid WMI device id 'wmi:%s' in '%s'\n", @@ -1260,7 +1262,31 @@ static void do_wmi_entry(struct module *mod, void *symval) return; } - module_alias_printf(mod, false, WMI_MODULE_PREFIX "%s", *guid_string); + for (i = 0; i < UUID_STRING_LEN; i++) { + char value = (*guid_string)[i]; + bool valid = false; + + if (i == 8 || i == 13 || i == 18 || i == 23) { + if (value == '-') + valid = true; + } else { + if (isxdigit(value)) + valid = true; + } + + if (!valid) { + warn("Invalid character %c inside WMI GUID string '%s' in '%s'\n", + value, *guid_string, mod->name); + return; + } + + /* Some GUIDs from BMOF definitions contain lowercase characters */ + result[i] = toupper(value); + } + + result[i] = '\0'; + + module_alias_printf(mod, false, WMI_MODULE_PREFIX "%s", result); } /* Looks like: mhi:S */ -- cgit v1.2.3