usermodehelper: check subprocess_info->path != NULL
authorOleg Nesterov <oleg@redhat.com>
Thu, 16 May 2013 15:43:55 +0000 (17:43 +0200)
committerBen Hutchings <ben@decadent.org.uk>
Thu, 30 May 2013 13:35:00 +0000 (14:35 +0100)
commitb5bcd909bef8caf59cfc85f02ac2879419c89ab3
tree68ff9473d4fc4da06e9db70d46e066be10cf3f05
parent67544c758f9d9fbc27915ea34d6cd70b27f56104
usermodehelper: check subprocess_info->path != NULL

commit 264b83c07a84223f0efd0d1db9ccc66d6f88288f upstream.

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 <oleg@redhat.com>
Acked-By: Lucas De Marchi <lucas.demarchi@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
kernel/kmod.c