Hi Greg,
On Mon, Dec 28, 2020 at 11:49:38AM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> The patch below does not apply to the 4.19-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@xxxxxxxxxxxxxxx>.
Here is the backport.
--
Regards
Sudip
>From 3c70fbd5207444a0e0ede62ab991125dfd442d76 Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas@xxxxxxxxx>
Date: Mon, 7 Dec 2020 09:17:05 +0100
Subject: [PATCH] spi: pxa2xx: Fix use-after-free on unbind
commit 5626308bb94d9f930aa5f7c77327df4c6daa7759 upstream
pxa2xx_spi_remove() accesses the driver's private data after calling
spi_unregister_controller() even though that function releases the last
reference on the spi_controller and thereby frees the private data.
Fix by switching over to the new devm_spi_alloc_master/slave() helper
which keeps the private data accessible until the driver has unbound.
Fixes: 32e5b57232c0 ("spi: pxa2xx: Fix controller unregister order")
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v2.6.17+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: <stable@xxxxxxxxxxxxxxx> # v2.6.17+: 32e5b57232c0: spi: pxa2xx: Fix controller unregister order
Cc: <stable@xxxxxxxxxxxxxxx> # v2.6.17+
Link: https://lore.kernel.org/r/5764b04d4a6e43069ebb7808f64c2f774ac6f193.1607286887.git.lukas@xxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
[sudip: adjust context]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@xxxxxxxxx>
---
drivers/spi/spi-pxa2xx.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/spi/spi-pxa2xx.c b/drivers/spi/spi-pxa2xx.c
index eafd0c2135a1..a889505e978b 100644
--- a/drivers/spi/spi-pxa2xx.c
+++ b/drivers/spi/spi-pxa2xx.c
@@ -1572,7 +1572,7 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
return -ENODEV;
}
- master = spi_alloc_master(dev, sizeof(struct driver_data));
+ master = devm_spi_alloc_master(dev, sizeof(*drv_data));
if (!master) {
dev_err(&pdev->dev, "cannot alloc spi_master\n");
pxa_ssp_free(ssp);
@@ -1759,7 +1759,6 @@ static int pxa2xx_spi_probe(struct platform_device *pdev)
free_irq(ssp->irq, drv_data);
out_error_master_alloc:
- spi_controller_put(master);
pxa_ssp_free(ssp);
return status;
}
--
2.11.0
