From: Sascha Hauer <s.hauer@pengutronix.de>
To: linux-spi@vger.kernel.org
Cc: Mark Brown <broonie@kernel.org>,
Vladimir Oltean <olteanv@gmail.com>,
kernel@pengutronix.de, Sascha Hauer <s.hauer@pengutronix.de>
Subject: [PATCH] spi: fsl-dspi: fix use-after-free in remove path
Date: Wed, 23 Sep 2020 15:10:26 +0200 [thread overview]
Message-ID: <20200923131026.20707-1-s.hauer@pengutronix.de> (raw)
spi_unregister_controller() not only unregisters the controller, but
also frees the controller. This will free the driver data with it, so
we must not access it later dspi_remove().
Solve this by allocating the driver data separately from the SPI
controller.
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
---
This fixes the issue reported at https://marc.info/?l=linux-spi&m=160068648808293&w=2
for the fsl-dspi driver in the way Mark suggested. A whole lot of other SPI drivers
are affected by this issue and need a similar fix. Here is a fix for the driver
I currently care about.
drivers/spi/spi-fsl-dspi.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)
diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c
index 91c6affe139c..aae9f9a7aea6 100644
--- a/drivers/spi/spi-fsl-dspi.c
+++ b/drivers/spi/spi-fsl-dspi.c
@@ -1273,11 +1273,14 @@ static int dspi_probe(struct platform_device *pdev)
void __iomem *base;
bool big_endian;
- ctlr = spi_alloc_master(&pdev->dev, sizeof(struct fsl_dspi));
+ dspi = devm_kzalloc(&pdev->dev, sizeof(*dspi), GFP_KERNEL);
+ if (!dspi)
+ return -ENOMEM;
+
+ ctlr = spi_alloc_master(&pdev->dev, 0);
if (!ctlr)
return -ENOMEM;
- dspi = spi_controller_get_devdata(ctlr);
dspi->pdev = pdev;
dspi->ctlr = ctlr;
@@ -1414,7 +1417,7 @@ static int dspi_probe(struct platform_device *pdev)
if (dspi->devtype_data->trans_mode != DSPI_DMA_MODE)
ctlr->ptp_sts_supported = true;
- platform_set_drvdata(pdev, ctlr);
+ platform_set_drvdata(pdev, dspi);
ret = spi_register_controller(ctlr);
if (ret != 0) {
@@ -1437,8 +1440,7 @@ static int dspi_probe(struct platform_device *pdev)
static int dspi_remove(struct platform_device *pdev)
{
- struct spi_controller *ctlr = platform_get_drvdata(pdev);
- struct fsl_dspi *dspi = spi_controller_get_devdata(ctlr);
+ struct fsl_dspi *dspi = platform_get_drvdata(pdev);
/* Disconnect from the SPI framework */
spi_unregister_controller(dspi->ctlr);
--
2.28.0
next reply other threads:[~2020-09-23 13:10 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-23 13:10 Sascha Hauer [this message]
2020-09-23 19:00 ` [PATCH] spi: fsl-dspi: fix use-after-free in remove path Mark Brown
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20200923131026.20707-1-s.hauer@pengutronix.de \
--to=s.hauer@pengutronix.de \
--cc=broonie@kernel.org \
--cc=kernel@pengutronix.de \
--cc=linux-spi@vger.kernel.org \
--cc=olteanv@gmail.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).