From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f193.google.com ([209.85.128.193]:53959 "EHLO mail-wr0-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751167AbdJ2Rog (ORCPT ); Sun, 29 Oct 2017 13:44:36 -0400 References: <20171029120133.32585-1-johan@kernel.org> From: Rui Miguel Silva To: Johan Hovold Cc: Rui Miguel Silva , Viresh Kumar , Alex Elder , Greg Kroah-Hartman , greybus-dev@lists.linaro.org, devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, stable Subject: Re: [PATCH] staging: greybus: spilib: fix use-after-free after deregistration In-reply-to: <20171029120133.32585-1-johan@kernel.org> Date: Sun, 29 Oct 2017 17:44:31 +0000 Message-ID: MIME-Version: 1.0 Content-Type: text/plain Sender: stable-owner@vger.kernel.org List-ID: Hi Johan, Thanks for the patch. On Sun 29 Oct 2017 at 12:01, Johan Hovold wrote: > 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 Reviewed-by: Rui Miguel Silva --- Cheers, Rui > --- > 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);