From 6e3837668e00fb914ac2b43158ef51b027ec385c Mon Sep 17 00:00:00 2001 From: Michael Walle Date: Mon, 28 Sep 2020 10:55:00 +0200 Subject: spi: fsl-dspi: fix NULL pointer dereference Since commit 530b5affc675 ("spi: fsl-dspi: fix use-after-free in remove path") this driver causes a kernel oops: [ 1.891065] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080 [..] [ 2.056973] Call trace: [ 2.059425] dspi_setup+0xc8/0x2e0 [ 2.062837] spi_setup+0xcc/0x248 [ 2.066160] spi_add_device+0xb4/0x198 [ 2.069918] of_register_spi_device+0x250/0x370 [ 2.074462] spi_register_controller+0x4f4/0x770 [ 2.079094] dspi_probe+0x5bc/0x7b0 [ 2.082594] platform_drv_probe+0x5c/0xb0 [ 2.086615] really_probe+0xec/0x3c0 [ 2.090200] driver_probe_device+0x60/0xc0 [ 2.094308] device_driver_attach+0x7c/0x88 [ 2.098503] __driver_attach+0x60/0xe8 [ 2.102263] bus_for_each_dev+0x7c/0xd0 [ 2.106109] driver_attach+0x2c/0x38 [ 2.109692] bus_add_driver+0x194/0x1f8 [ 2.113538] driver_register+0x6c/0x128 [ 2.117385] __platform_driver_register+0x50/0x60 [ 2.122105] fsl_dspi_driver_init+0x24/0x30 [ 2.126302] do_one_initcall+0x54/0x2d0 [ 2.130149] kernel_init_freeable+0x1ec/0x258 [ 2.134520] kernel_init+0x1c/0x120 [ 2.138018] ret_from_fork+0x10/0x34 [ 2.141606] Code: 97e0b11d aa0003f3 b4000680 f94006e0 (f9404000) [ 2.147723] ---[ end trace 26cf63e6cbba33a8 ]--- This is because since this commit, the allocation of the drivers private data is done explicitly and in this case spi_alloc_master() won't set the correct pointer. Also move the platform_set_drvdata() to have both next to each other. Fixes: 530b5affc675 ("spi: fsl-dspi: fix use-after-free in remove path") Signed-off-by: Michael Walle Tested-by: Sascha Hauer Reviewed-by: Krzysztof Kozlowski Link: https://lore.kernel.org/r/20200928085500.28254-1-michael@walle.cc Signed-off-by: Mark Brown --- drivers/spi/spi-fsl-dspi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/spi/spi-fsl-dspi.c b/drivers/spi/spi-fsl-dspi.c index 127323a4b27c..108a7d50d2c3 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -1281,6 +1281,9 @@ static int dspi_probe(struct platform_device *pdev) if (!ctlr) return -ENOMEM; + spi_controller_set_devdata(ctlr, dspi); + platform_set_drvdata(pdev, dspi); + dspi->pdev = pdev; dspi->ctlr = ctlr; @@ -1417,8 +1420,6 @@ poll_mode: if (dspi->devtype_data->trans_mode != DSPI_DMA_MODE) ctlr->ptp_sts_supported = true; - platform_set_drvdata(pdev, dspi); - ret = spi_register_controller(ctlr); if (ret != 0) { dev_err(&pdev->dev, "Problem registering DSPI ctlr\n"); -- cgit