From 264b83c07a84223f0efd0d1db9ccc66d6f88288f Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Thu, 16 May 2013 17:43:55 +0200 Subject: [PATCH] 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 Acked-By: Lucas De Marchi Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds --- kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/kmod.c b/kernel/kmod.c index 1296e72e4161..8241906c4b61 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -569,6 +569,11 @@ 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;