On Mon, Dec 28, 2020 at 12:01:44PM +0100, gregkh@linuxfoundation.org wrote:
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.
Sorry for the delay, here's the backport of 8f96c434dfbc to v5.4-stable:
-- >8 -- 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
commit 8f96c434dfbc85ffa755d6634c8c1cb2233fcf24 upstream.
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.
Fix by switching over to the new devm_spi_alloc_master() helper which keeps the private data accessible until the driver has unbound.
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 [lukas: backport to v5.4.123] Signed-off-by: Lukas Wunner lukas@wunner.de --- drivers/spi/spi-geni-qcom.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/spi/spi-geni-qcom.c b/drivers/spi/spi-geni-qcom.c index 6f3d64a1a2b3..01b53d816497 100644 --- a/drivers/spi/spi-geni-qcom.c +++ b/drivers/spi/spi-geni-qcom.c @@ -552,7 +552,7 @@ static int spi_geni_probe(struct platform_device *pdev) return PTR_ERR(clk); }
- spi = spi_alloc_master(&pdev->dev, sizeof(*mas)); + spi = devm_spi_alloc_master(&pdev->dev, sizeof(*mas)); if (!spi) return -ENOMEM;
@@ -599,7 +599,6 @@ static int spi_geni_probe(struct platform_device *pdev) free_irq(mas->irq, spi); spi_geni_probe_runtime_disable: pm_runtime_disable(&pdev->dev); - spi_master_put(spi); return ret; }