From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f66.google.com ([209.85.215.66]:47631 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750915AbdJ2MB7 (ORCPT ); Sun, 29 Oct 2017 08:01:59 -0400 From: Johan Hovold To: Rui Miguel Silva , Viresh Kumar Cc: Johan Hovold , Alex Elder , Greg Kroah-Hartman , greybus-dev@lists.linaro.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, stable Subject: [PATCH] staging: greybus: spilib: fix use-after-free after deregistration Date: Sun, 29 Oct 2017 13:01:33 +0100 Message-Id: <20171029120133.32585-1-johan@kernel.org> Sender: stable-owner@vger.kernel.org List-ID: Remove erroneous spi_master_put() after controller deregistration which would access the already freed spi controller. Note that spi_unregister_master() drops our only controller reference. Fixes: ba3e67001b42 ("greybus: SPI: convert to a gpbridge driver") Cc: stable # 4.9 Cc: Greg Kroah-Hartman Signed-off-by: Johan Hovold --- drivers/staging/greybus/spilib.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/staging/greybus/spilib.c b/drivers/staging/greybus/spilib.c index e97b19148497..1e7321a1404c 100644 --- a/drivers/staging/greybus/spilib.c +++ b/drivers/staging/greybus/spilib.c @@ -544,11 +544,14 @@ int gb_spilib_master_init(struct gb_connection *connection, struct device *dev, return 0; -exit_spi_unregister: - spi_unregister_master(master); exit_spi_put: spi_master_put(master); + return ret; + +exit_spi_unregister: + spi_unregister_master(master); + return ret; } EXPORT_SYMBOL_GPL(gb_spilib_master_init); @@ -558,7 +561,6 @@ void gb_spilib_master_exit(struct gb_connection *connection) struct spi_master *master = gb_connection_get_data(connection); spi_unregister_master(master); - spi_master_put(master); } EXPORT_SYMBOL_GPL(gb_spilib_master_exit); -- 2.14.3