From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Oleg Nesterov , Lucas De Marchi , Linus Torvalds Subject: [ 095/102] usermodehelper: check subprocess_info->path != NULL Date: Fri, 17 May 2013 14:36:50 -0700 Message-Id: <20130517213254.214204806@linuxfoundation.org> In-Reply-To: <20130517213244.277411019@linuxfoundation.org> References: <20130517213244.277411019@linuxfoundation.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Oleg Nesterov 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 Acked-By: Lucas De Marchi Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -570,6 +570,11 @@ int call_usermodehelper_exec(struct subp int retval = 0; helper_lock(); + if (!sub_info->path) { + retval = -EINVAL; + goto out; + } + if (sub_info->path[0] == '\0') goto out;