usermodehelper: check subprocess_info->path != NULL

argv_split(empty_or_all_spaces) happily succeeds, it simply returns
argc == 0 and argv[0] == NULL. Change call_usermodehelper_exec() to
check sub_info->path != NULL to avoid the crash.

This is the minimal fix, todo:

 - perhaps we should change argv_split() to return NULL or change the
   callers.

 - kill or justify ->path[0] check

 - narrow the scope of helper_lock()

Signed-off-by: Oleg Nesterov <[email protected]>
Acked-By: Lucas De Marchi <[email protected]>
Cc: [email protected]
Signed-off-by: Linus Torvalds <[email protected]>

0 files changed, 0 insertions, 0 deletions