On Mon, Nov 23, 2020 at 09:52:50AM +0100, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 4.9-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.
Below please find the backport of 63c5395bb7a9 to the 4.9-stable tree. It depends on the backport of 5e844cc37a5c I just sent out.
Thanks!
-- >8 -- Subject: [PATCH] spi: bcm-qspi: Fix use-after-free on unbind
[ Upstream commit 63c5395bb7a9777a33f0e7b5906f2c0170a23692 ]
bcm_qspi_remove() calls spi_unregister_master() even though bcm_qspi_probe() calls devm_spi_register_master(). The spi_master is therefore unregistered and freed twice on unbind.
Fix by switching over to the new devm_spi_alloc_master() helper which keeps the private data accessible until the driver has unbound.
While at it, fix an ordering issue in bcm_qspi_remove() wherein spi_unregister_master() is called after uninitializing the hardware, disabling the clock and freeing an IRQ data structure. The correct order is to call spi_unregister_master() *before* those teardown steps because bus accesses may still be ongoing until that function returns.
Fixes: fa236a7ef240 ("spi: bcm-qspi: Add Broadcom MSPI driver") Signed-off-by: Lukas Wunner lukas@wunner.de Cc: stable@vger.kernel.org # v4.9+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation Cc: stable@vger.kernel.org # v4.9+ Cc: Kamal Dasu kdasu.kdev@gmail.com Acked-by: Florian Fainelli f.fainelli@gmail.com Tested-by: Florian Fainelli f.fainelli@gmail.com Link: https://lore.kernel.org/r/5e31a9a59fd1c0d0b795b2fe219f25e5ee855f9d.160512103... Signed-off-by: Mark Brown broonie@kernel.org --- drivers/spi/spi-bcm-qspi.c | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-)
diff --git a/drivers/spi/spi-bcm-qspi.c b/drivers/spi/spi-bcm-qspi.c index 1906b2319e5b..5453910d8abc 100644 --- a/drivers/spi/spi-bcm-qspi.c +++ b/drivers/spi/spi-bcm-qspi.c @@ -1185,7 +1185,7 @@ int bcm_qspi_probe(struct platform_device *pdev, if (!of_match_node(bcm_qspi_of_match, dev->of_node)) return -ENODEV;
- master = spi_alloc_master(dev, sizeof(struct bcm_qspi)); + master = devm_spi_alloc_master(dev, sizeof(struct bcm_qspi)); if (!master) { dev_err(dev, "error allocating spi_master\n"); return -ENOMEM; @@ -1218,21 +1218,17 @@ int bcm_qspi_probe(struct platform_device *pdev,
if (res) { qspi->base[MSPI] = devm_ioremap_resource(dev, res); - if (IS_ERR(qspi->base[MSPI])) { - ret = PTR_ERR(qspi->base[MSPI]); - goto qspi_resource_err; - } + if (IS_ERR(qspi->base[MSPI])) + return PTR_ERR(qspi->base[MSPI]); } else { - goto qspi_resource_err; + return 0; }
res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "bspi"); if (res) { qspi->base[BSPI] = devm_ioremap_resource(dev, res); - if (IS_ERR(qspi->base[BSPI])) { - ret = PTR_ERR(qspi->base[BSPI]); - goto qspi_resource_err; - } + if (IS_ERR(qspi->base[BSPI])) + return PTR_ERR(qspi->base[BSPI]); qspi->bspi_mode = true; } else { qspi->bspi_mode = false; @@ -1243,18 +1239,14 @@ int bcm_qspi_probe(struct platform_device *pdev, res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "cs_reg"); if (res) { qspi->base[CHIP_SELECT] = devm_ioremap_resource(dev, res); - if (IS_ERR(qspi->base[CHIP_SELECT])) { - ret = PTR_ERR(qspi->base[CHIP_SELECT]); - goto qspi_resource_err; - } + if (IS_ERR(qspi->base[CHIP_SELECT])) + return PTR_ERR(qspi->base[CHIP_SELECT]); }
qspi->dev_ids = kcalloc(num_irqs, sizeof(struct bcm_qspi_dev_id), GFP_KERNEL); - if (!qspi->dev_ids) { - ret = -ENOMEM; - goto qspi_resource_err; - } + if (!qspi->dev_ids) + return -ENOMEM;
for (val = 0; val < num_irqs; val++) { irq = -1; @@ -1330,7 +1322,7 @@ int bcm_qspi_probe(struct platform_device *pdev, qspi->xfer_mode.addrlen = -1; qspi->xfer_mode.hp = -1;
- ret = devm_spi_register_master(&pdev->dev, master); + ret = spi_register_master(master); if (ret < 0) { dev_err(dev, "can't register master\n"); goto qspi_reg_err; @@ -1343,8 +1335,6 @@ int bcm_qspi_probe(struct platform_device *pdev, clk_disable_unprepare(qspi->clk); qspi_probe_err: kfree(qspi->dev_ids); -qspi_resource_err: - spi_master_put(master); return ret; } /* probe function to be called by SoC specific platform driver probe */ @@ -1355,10 +1345,10 @@ int bcm_qspi_remove(struct platform_device *pdev) struct bcm_qspi *qspi = platform_get_drvdata(pdev);
platform_set_drvdata(pdev, NULL); + spi_unregister_master(qspi->master); bcm_qspi_hw_uninit(qspi); clk_disable_unprepare(qspi->clk); kfree(qspi->dev_ids); - spi_unregister_master(qspi->master);
return 0; }