From d94881fd10933ffe39a21a43e0a57bf279c59205 Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 3 Jul 2013 15:08:15 -0700 Subject: [PATCH] usermodehelper: kill the sub_info->path[0] check call_usermodehelper_exec() does nothing but returns success if path[0] == 0. The only user which needs this strange feature is request_module(), it can check modprobe_path[0] itself like other users do if they want to detect the "disabled by admin" case. Kill it. Not only it looks strange, it can confuse other callers. And this allows us to revert 5eb95658 ("usermodehelper: check subprocess_info->path != NULL"), do_execve(NULL) is safe. Signed-off-by: Oleg Nesterov Acked-by: Rusty Russell Cc: Lucas De Marchi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/kmod.c | 11 +++-------- 1 file changed, 3 insertions(+), 8 deletions(-) diff --git a/kernel/kmod.c b/kernel/kmod.c index 8241906c4b61a..fb326365b6946 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -147,6 +147,9 @@ int __request_module(bool wait, const char *fmt, ...) */ WARN_ON_ONCE(wait && current_is_async()); + if (!modprobe_path[0]) + return 0; + va_start(args, fmt); ret = vsnprintf(module_name, MODULE_NAME_LEN, fmt, args); va_end(args); @@ -569,14 +572,6 @@ int call_usermodehelper_exec(struct subprocess_info *sub_info, int wait) int retval = 0; helper_lock(); - if (!sub_info->path) { - retval = -EINVAL; - goto out; - } - - if (sub_info->path[0] == '\0') - goto out; - if (!khelper_wq || usermodehelper_disabled) { retval = -EBUSY; goto out; -- 2.39.5