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spi: spi-sh: Fix use-after-free on unbind 

commit e77df3eca1 upstream.

spi_sh_remove() accesses the driver's private data after calling
spi_unregister_master() even though that function releases the last
reference on the spi_master and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master() helper which
keeps the private data accessible until the driver has unbound.

Fixes: 680c1305e2 ("spi/spi_sh: use spi_unregister_master instead of spi_master_put in remove path")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v3.0+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: <stable@vger.kernel.org> # v3.0+
Cc: Axel Lin <axel.lin@ingics.com>
Link: https://lore.kernel.org/r/6d97628b536baf01d5e3e39db61108f84d44c8b2.1607286887.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Lukas Wunner 2020-12-07 09:17:04 +01:00 committed by Greg Kroah-Hartman
parent 17360c3af1
commit bd6d736dbf
1 changed files with 4 additions and 9 deletions
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13
drivers/spi/spi-sh.c
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@ -440,7 +440,7 @@ static int spi_sh_probe(struct platform_device *pdev)
if (irq < 0)
return irq;
master = spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
master = devm_spi_alloc_master(&pdev->dev, sizeof(struct spi_sh_data));
if (master == NULL) {
dev_err(&pdev->dev, "spi_alloc_master error.\n");
return -ENOMEM;
@ -458,16 +458,14 @@ static int spi_sh_probe(struct platform_device *pdev)
break;
default:
dev_err(&pdev->dev, "No support width\n");
ret = -ENODEV;
goto error1;
return -ENODEV;
}
ss->irq = irq;
ss->master = master;
ss->addr = devm_ioremap(&pdev->dev, res->start, resource_size(res));
if (ss->addr == NULL) {
dev_err(&pdev->dev, "ioremap error.\n");
ret = -ENOMEM;
goto error1;
return -ENOMEM;
}
INIT_LIST_HEAD(&ss->queue);
spin_lock_init(&ss->lock);
@ -477,7 +475,7 @@ static int spi_sh_probe(struct platform_device *pdev)
ret = request_irq(irq, spi_sh_irq, 0, "spi_sh", ss);
if (ret < 0) {
dev_err(&pdev->dev, "request_irq error\n");
goto error1;
return ret;
}
master->num_chipselect = 2;
@ -496,9 +494,6 @@ static int spi_sh_probe(struct platform_device *pdev)
error3:
free_irq(irq, ss);
error1:
spi_master_put(master);
return ret;
}