This is a note to let you know that I've just added the patch titled
spi: lpspi: Fix use-after-free on unbind
to the 5.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
spi-lpspi-fix-use-after-free-on-unbind.patch
and it can be found in the queue-5.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 4def49da620c84a682d9361d6bef0a97eed46fe0 Mon Sep 17 00:00:00 2001
From: Lukas Wunner <lukas@xxxxxxxxx>
Date: Sun, 8 Nov 2020 23:41:00 +0100
Subject: spi: lpspi: Fix use-after-free on unbind
From: Lukas Wunner <lukas@xxxxxxxxx>
commit 4def49da620c84a682d9361d6bef0a97eed46fe0 upstream.
Normally the last reference on an spi_controller is released by
spi_unregister_controller(). In the case of the i.MX lpspi driver,
the spi_controller is registered with devm_spi_register_controller(),
so spi_unregister_controller() is invoked automatically after the driver
has unbound.
However the driver already releases the last reference in
fsl_lpspi_remove() through a gratuitous call to spi_master_put(),
causing a use-after-free when spi_unregister_controller() is
subsequently invoked by the devres framework.
Fix by dropping the superfluous spi_master_put().
Fixes: 944c01a889d9 ("spi: lpspi: enable runtime pm for lpspi")
Signed-off-by: Lukas Wunner <lukas@xxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v5.2+
Cc: Han Xu <han.xu@xxxxxxx>
Link: https://lore.kernel.org/r/ab3c0b18bd820501a12c85e440006e09ec0e275f.1604874488.git.lukas@xxxxxxxxx
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi-fsl-lpspi.c | 3 ---
1 file changed, 3 deletions(-)
--- a/drivers/spi/spi-fsl-lpspi.c
+++ b/drivers/spi/spi-fsl-lpspi.c
@@ -938,9 +938,6 @@ static int fsl_lpspi_remove(struct platf
spi_controller_get_devdata(controller);
pm_runtime_disable(fsl_lpspi->dev);
-
- spi_master_put(controller);
-
return 0;
}
Patches currently in stable-queue which might be from lukas@xxxxxxxxx are
queue-5.9/spi-bcm2835aux-fix-use-after-free-on-unbind.patch
queue-5.9/spi-lpspi-fix-use-after-free-on-unbind.patch
queue-5.9/spi-npcm-fiu-don-t-leak-spi-master-in-probe-error-path.patch
queue-5.9/spi-introduce-device-managed-spi-controller-allocation.patch
