Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965275AbbHDOnA (ORCPT ); Tue, 4 Aug 2015 10:43:00 -0400 Received: from mx2.suse.de ([195.135.220.15]:59454 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965231AbbHDOmz (ORCPT ); Tue, 4 Aug 2015 10:42:55 -0400 X-Amavis-Alert: BAD HEADER SECTION, Duplicate header field: "References" From: Jiri Slaby To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Linus Torvalds , Jiri Slaby Subject: [PATCH 3.12 121/123] Fix firmware loader uevent buffer NULL pointer dereference Date: Tue, 4 Aug 2015 16:41:05 +0200 Message-Id: X-Mailer: git-send-email 2.5.0 In-Reply-To: References: In-Reply-To: References: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2438 Lines: 69 From: Linus Torvalds 3.12-stable review patch. If anyone has any objections, please let me know. =============== 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: Jiri Slaby --- drivers/base/firmware_class.c | 16 +++++++++++++--- 1 file changed, 13 insertions(+), 3 deletions(-) diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index ec85b816fd5a..cdd151e2d122 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -527,10 +527,8 @@ static void fw_dev_release(struct device *dev) 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)) @@ -541,6 +539,18 @@ static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) 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, -- 2.5.0 -- 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/