From 7f57cfa4e2aa29fabe69e41529fd26578adc9b58 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
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 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>
---
kernel/kmod.c | 11 +++--------
1 file changed, 3 insertions(+), 8 deletions(-)
diff --git a/kernel/kmod.c b/kernel/kmod.c
index 8241906c4b61..fb326365b694 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;
--
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