From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934201Ab3E1V3L (ORCPT ); Tue, 28 May 2013 17:29:11 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:59823 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933837Ab3E1V0E (ORCPT ); Tue, 28 May 2013 17:26:04 -0400 From: Kamal Mostafa To: linux-kernel@vger.kernel.org, stable@vger.kernel.org, kernel-team@lists.ubuntu.com Cc: Oleg Nesterov , Linus Torvalds , Kamal Mostafa Subject: [PATCH 50/78] usermodehelper: check subprocess_info->path != NULL Date: Tue, 28 May 2013 14:19:59 -0700 Message-Id: <1369776027-17859-51-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 In-Reply-To: <1369776027-17859-1-git-send-email-kamal@canonical.com> References: <1369776027-17859-1-git-send-email-kamal@canonical.com> X-Extended-Stable: 3.8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.8.13.1 -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: Kamal Mostafa --- kernel/kmod.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/kmod.c b/kernel/kmod.c index 0023a87..41e1524 100644 --- a/kernel/kmod.c +++ b/kernel/kmod.c @@ -561,6 +561,11 @@ 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; -- 1.8.1.2