Commit 7f57cfa4 authored Jul 03, 2013 by Oleg Nesterov Committed by Linus Torvalds Jul 03, 2013

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>

parent 77d55918

kernel/kmod.c

+3 −8

Original line number	Diff line number	Diff line
		@@ -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;

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