Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755202AbbGaUEW (ORCPT ); Fri, 31 Jul 2015 16:04:22 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:46932 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161065AbbGaUDH (ORCPT ); Fri, 31 Jul 2015 16:03:07 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ming Lei , Linus Torvalds Subject: [PATCH 4.1 267/267] Fix firmware loader uevent buffer NULL pointer dereference Date: Fri, 31 Jul 2015 12:41:58 -0700 Message-Id: <20150731194012.077970403@linuxfoundation.org> X-Mailer: git-send-email 2.5.0 In-Reply-To: <20150731194001.933895871@linuxfoundation.org> References: <20150731194001.933895871@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2298 Lines: 67 4.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Torvalds commit 6f957724b94cb19f5c1c97efd01dd4df8ced323c upstream. The firmware class uevent function accessed the "fw_priv->buf" buffer without the proper locking and testing for NULL. This is an old bug (looks like it goes back to 2012 and commit 1244691c73b2: "firmware loader: introduce firmware_buf"), but for some reason it's triggering only now in 4.2-rc1. Shuah Khan is trying to bisect what it is that causes this to trigger more easily, but in the meantime let's just fix the bug since others are hitting it too (at least Ingo reports having seen it as well). Reported-and-tested-by: Shuah Khan Acked-by: Ming Lei Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- drivers/base/firmware_class.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -544,10 +544,8 @@ static void fw_dev_release(struct device kfree(fw_priv); } -static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) +static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env) { - struct firmware_priv *fw_priv = to_firmware_priv(dev); - if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id)) return -ENOMEM; if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout)) @@ -558,6 +556,18 @@ static int firmware_uevent(struct device return 0; } +static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct firmware_priv *fw_priv = to_firmware_priv(dev); + int err = 0; + + mutex_lock(&fw_lock); + if (fw_priv->buf) + err = do_firmware_uevent(fw_priv, env); + mutex_unlock(&fw_lock); + return err; +} + static struct class firmware_class = { .name = "firmware", .class_attrs = firmware_class_attrs, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/