From 54745d563114b74f6fecebce68cd020d06c1772b Mon Sep 17 00:00:00 2001 From: Thorsten Blum Date: Tue, 18 Aug 2026 17:16:35 +0200 Subject: [PATCH] platform/x86: think-lmi: Fix current password length check MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit current_password_store() checks the password length before removing the trailing newline, which can reject valid passwords that are exactly ->maxlen bytes long. It also passes ->maxlen to strscpy(), which truncates passwords without a newline. Use strchrnul() to measure the password length up to the newline, then copy that many bytes and add a trailing NUL terminator using strscpy(). Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms") Cc: stable@vger.kernel.org Reviewed-by: Mark Pearson Signed-off-by: Thorsten Blum Link: https://patch.msgid.link/20260818151635.37094-2-thorsten.blum@linux.dev Reviewed-by: Ilpo Järvinen Signed-off-by: Ilpo Järvinen --- drivers/platform/x86/lenovo/think-lmi.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/drivers/platform/x86/lenovo/think-lmi.c b/drivers/platform/x86/lenovo/think-lmi.c index ca266657e16c..a0e3fa766e37 100644 --- a/drivers/platform/x86/lenovo/think-lmi.c +++ b/drivers/platform/x86/lenovo/think-lmi.c @@ -438,14 +438,13 @@ static ssize_t current_password_store(struct kobject *kobj, struct tlmi_pwd_setting *setting = to_tlmi_pwd_setting(kobj); size_t pwdlen; - pwdlen = strlen(buf); + /* Strip newline; setting password won't work if one is present. */ + pwdlen = strchrnul(buf, '\n') - buf; /* pwdlen == 0 is allowed to clear the password */ if (pwdlen && ((pwdlen < setting->minlen) || (pwdlen > setting->maxlen))) return -EINVAL; - strscpy(setting->password, buf, setting->maxlen); - /* Strip out CR if one is present, setting password won't work if it is present */ - strreplace(setting->password, '\n', '\0'); + strscpy(setting->password, buf, pwdlen + 1); return count; }