The patch below does not apply to the 5.4-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@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8f96c434dfbc85ffa755d6634c8c1cb2233fcf24 Mon Sep 17 00:00:00 2001

From: Lukas Wunner lukas@wunner.de Date: Mon, 7 Dec 2020 09:17:02 +0100 Subject: [PATCH] spi: spi-geni-qcom: Fix use-after-free on unbind

spi_geni_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.

Moreover, since commit 1a9e489e6128 ("spi: spi-geni-qcom: Use OPP API to set clk/perf state"), spi_geni_probe() leaks the spi_master allocation if the calls to dev_pm_opp_set_clkname() or dev_pm_opp_of_add_table() fail.

Fix by switching over to the new devm_spi_alloc_master() helper which keeps the private data accessible until the driver has unbound and also avoids the spi_master leak on probe.

Fixes: 561de45f72bd ("spi: spi-geni-qcom: Add SPI driver support for GENI based QUP") Signed-off-by: Lukas Wunner lukas@wunner.de Cc: stable@vger.kernel.org # v4.20+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation Cc: stable@vger.kernel.org # v4.20+ Cc: Rajendra Nayak rnayak@codeaurora.org Cc: Girish Mahadevan girishm@codeaurora.org Link: https://lore.kernel.org/r/dfa1d8c41b8acdfad87ec8654cd124e6e3cb3f31.160728688... Signed-off-by: Mark Brown broonie@kernel.org

diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index 25810a7eef10..0e3d8e6c08f4 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -603,7 +603,7 @@ static int spi_geni_probe(struct platform_device *pdev) if (IS_ERR(clk)) return PTR_ERR(clk);

- spi = spi_alloc_master(dev, sizeof(*mas)); + spi = devm_spi_alloc_master(dev, sizeof(*mas)); if (!spi) return -ENOMEM;

@@ -673,7 +673,6 @@ static int spi_geni_probe(struct platform_device *pdev) free_irq(mas->irq, spi); spi_geni_probe_runtime_disable: pm_runtime_disable(dev); - spi_master_put(spi); dev_pm_opp_of_remove_table(&pdev->dev); put_clkname: dev_pm_opp_put_clkname(mas->se.opp_table);