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 264b83c0 ("usermodehelper: check
subprocess_info->path != NULL"), do_execve(NULL) is safe.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Lucas De Marchi <lucas.de.marchi@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 8241906..fb32636 100644
--- a/kernel/kmod.c
+++ b/kernel/kmod.c
@@ -147,6 +147,9 @@
*/
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 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;