Linux-SPI Archive on lore.kernel.org
 help / color / Atom feed
From: Lukas Wunner <lukas@wunner.de>
To: Mark Brown <broonie@kernel.org>
Cc: linux-spi@vger.kernel.org,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Stefan Roese <sr@denx.de>
Subject: [PATCH for-5.10] spi: mt7621: Don't leak SPI master in probe error path
Date: Mon, 16 Nov 2020 09:23:07 +0100
Message-ID: <800f7035a29c1ae65386f2e17a2b5ef9d2b39268.1605512876.git.lukas@wunner.de> (raw)
In-Reply-To: <73adc6ba84a4f968f2e1499a776e5c928fbdde56.1605512876.git.lukas@wunner.de>

If the calls to device_reset() or devm_spi_register_controller() fail on
probe of the MediaTek MT7621 SPI driver, the spi_controller struct is
erroneously not freed.  Fix by switching over to the new
devm_spi_alloc_master() helper.

Moreover, the SYS clock is enabled on probe but not disabled if any of
the subsequent probe steps fails.

Finally, there's an ordering issue in mt7621_spi_remove() wherein
the spi_controller is unregistered after disabling the SYS clock.
The correct order is to call spi_unregister_controller() *before* this
teardown step because bus accesses may still be ongoing until that
function returns.

All of these bugs have existed since the driver was first introduced,
so it seems fair to fix them together in a single commit.

Fixes: 1ab7f2a43558 ("staging: mt7621-spi: add mt7621 support")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v4.17+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: <stable@vger.kernel.org> # v4.17+
---
 drivers/spi/spi-mt7621.c | 18 ++++++++++++++----
 1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-mt7621.c b/drivers/spi/spi-mt7621.c
index 2c3b7a2a1ec7..d7cda66c4b26 100644
--- a/drivers/spi/spi-mt7621.c
+++ b/drivers/spi/spi-mt7621.c
@@ -350,10 +350,11 @@ static int mt7621_spi_probe(struct platform_device *pdev)
 	if (status)
 		return status;
 
-	master = spi_alloc_master(&pdev->dev, sizeof(*rs));
+	master = devm_spi_alloc_master(&pdev->dev, sizeof(*rs));
 	if (!master) {
 		dev_info(&pdev->dev, "master allocation failed\n");
-		return -ENOMEM;
+		ret = -ENOMEM;
+		goto err_clk_disable;
 	}
 
 	master->mode_bits = SPI_LSB_FIRST;
@@ -377,10 +378,18 @@ static int mt7621_spi_probe(struct platform_device *pdev)
 	ret = device_reset(&pdev->dev);
 	if (ret) {
 		dev_err(&pdev->dev, "SPI reset failed!\n");
-		return ret;
+		goto err_clk_disable;
 	}
 
-	return devm_spi_register_controller(&pdev->dev, master);
+	ret = spi_register_controller(master);
+	if (ret)
+		goto err_clk_disable;
+
+	return 0;
+
+err_clk_disable:
+	clk_disable_unprepare(clk);
+	return ret;
 }
 
 static int mt7621_spi_remove(struct platform_device *pdev)
@@ -391,6 +400,7 @@ static int mt7621_spi_remove(struct platform_device *pdev)
 	master = dev_get_drvdata(&pdev->dev);
 	rs = spi_controller_get_devdata(master);
 
+	spi_unregister_controller(master);
 	clk_disable_unprepare(rs->clk);
 
 	return 0;
-- 
2.28.0


  parent reply index

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-11-16  8:23 [PATCH for-5.10] spi: spi-geni-qcom: Fix use-after-free on unbind Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] spi: spi-qcom-qspi: " Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] spi: spi-sh: " Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] spi: pxa2xx: " Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] spi: rpc-if: " Lukas Wunner
2020-11-28 20:20   ` Sergey Shtylyov
2020-11-29 11:35     ` Lukas Wunner
2020-11-30 19:18       ` Sergey Shtylyov
2020-12-02 11:43         ` Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] spi: mxic: Don't leak SPI master in probe error path Lukas Wunner
2020-11-16  8:23 ` Lukas Wunner [this message]
2020-11-16 11:05   ` [PATCH for-5.10] spi: mt7621: " Stefan Roese
2020-11-16  8:23 ` [PATCH for-5.10] spi: spi-mtk-nor: " Lukas Wunner
2020-11-17  4:02   ` Ikjoon Jang
2020-11-17 12:32   ` Mark Brown
2020-11-16  8:23 ` [PATCH for-5.10] spi: gpio: " Lukas Wunner
2020-11-16 19:23   ` Andrey Smirnov
2020-11-16 23:03     ` Lukas Wunner
2020-11-16 23:59       ` Andrey Smirnov
2020-11-18  1:08   ` Linus Walleij
2020-11-16  8:23 ` [PATCH for-5.10] spi: npcm-fiu: " Lukas Wunner
2020-11-17 22:38   ` Mark Brown
2020-12-01 13:57   ` Mark Brown
2020-12-01 14:30     ` Lukas Wunner
2020-12-01 17:17       ` Mark Brown
2020-12-01 17:49         ` Lukas Wunner
2020-12-02 15:17           ` Mark Brown
2020-11-16  8:23 ` [PATCH for-5.10] spi: rb4xx: " Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] spi: sc18is602: " Lukas Wunner
2020-11-16  8:23 ` [PATCH for-5.10] media: netup_unidvb: " Lukas Wunner
2020-11-23 14:06   ` Mauro Carvalho Chehab
2020-12-01 13:57   ` 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=800f7035a29c1ae65386f2e17a2b5ef9d2b39268.1605512876.git.lukas@wunner.de \
    --to=lukas@wunner.de \
    --cc=broonie@kernel.org \
    --cc=linux-spi@vger.kernel.org \
    --cc=matthias.bgg@gmail.com \
    --cc=sr@denx.de \
    /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

Linux-SPI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-spi/0 linux-spi/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-spi linux-spi/ https://lore.kernel.org/linux-spi \
		linux-spi@vger.kernel.org
	public-inbox-index linux-spi

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-spi


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git