On Mon, 28 Sep 2020 at 14:26, Michael Walle michael@walle.cc wrote:

Since commit 530b5affc675 ("spi: fsl-dspi: fix use-after-free in remove path") this driver causes a kernel oops:

FYI, This reported issue is now happening on Linus's master 5.9.0-rc8 on arm64 nxp-ls2088 devices.

Crash log, ------------- [ 1.986452] fsl,ifc-nand 530000000.nand: IFC NAND device at 0x530000000, bank 2 [ 1.994751] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000080 [ 2.003542] Mem abort info: [ 2.006331] ESR = 0x96000004 [ 2.009380] EC = 0x25: DABT (current EL), IL = 32 bits [ 2.014718] SET = 0, FnV = 0 [ 2.017764] EA = 0, S1PTW = 0 [ 2.020908] Data abort info: [ 2.023787] ISV = 0, ISS = 0x00000004 [ 2.027621] CM = 0, WnR = 0 [ 2.030586] [0000000000000080] user address but active_mm is swapper [ 2.036940] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 2.042505] Modules linked in: [ 2.045553] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.9.0-rc8 #1 [ 2.051725] Hardware name: Freescale Layerscape 2088A RDB Board (DT) [ 2.058072] pstate: 40000005 (nZcv daif -PAN -UAO BTYPE=--) [ 2.063643] pc : dspi_setup+0x5c/0x2b0 [ 2.067383] lr : dspi_setup+0x278/0x2b0 [ 2.071209] sp : ffff80001005b900 [ 2.074514] x29: ffff80001005b900 x28: ffff0082ccd3f000 [ 2.079819] x27: ffffd73de0a704e0 x26: ffff0082edebc100 [ 2.085123] x25: 0000000000000001 x24: ffff0082edea6810 [ 2.090427] x23: ffffd73de15b6c40 x22: ffff0082ccd3f600 [ 2.095731] x21: ffff0082ee6b0000 x20: ffff0082cce51100 [ 2.101036] x19: ffff0082ccd3f800 x18: 0000000000000000 [ 2.106340] x17: ffffd73de088e6d8 x16: ffffd73de088e6e0 [ 2.111644] x15: ffff0082ee6b0480 x14: ffffffffffffffff [ 2.116947] x13: ffff0082cce51087 x12: ffff0082cce51085 [ 2.122251] x11: 0000000000000008 x10: 0101010101010101 [ 2.127554] x9 : 0000000000000000 x8 : ffff0082cce51180 [ 2.132858] x7 : 0000000000000000 x6 : 000000000000003f [ 2.138162] x5 : 0000000000000040 x4 : ffff80001005b8f0 [ 2.143466] x3 : 0000000000000001 x2 : 0000000000000dc0 [ 2.148770] x1 : e01dcf85cfcc6200 x0 : 0000000000000000 [ 2.154074] Call trace: [ 2.156512] dspi_setup+0x5c/0x2b0 [ 2.159906] spi_setup+0xcc/0x2e0 [ 2.163211] spi_add_device+0xec/0x218 [ 2.166951] of_register_spi_device+0x224/0x370 [ 2.171473] spi_register_controller+0x598/0x830 [ 2.176081] dspi_probe+0x32c/0x798 [ 2.179562] platform_drv_probe+0x5c/0xb0 [ 2.183564] really_probe+0xf0/0x4d8 [ 2.187131] driver_probe_device+0xfc/0x168 [ 2.191305] device_driver_attach+0x7c/0x88 [ 2.195478] __driver_attach+0xac/0x178 [ 2.199306] bus_for_each_dev+0x78/0xc8 [ 2.203134] driver_attach+0x2c/0x38 [ 2.206702] bus_add_driver+0x14c/0x230 [ 2.210529] driver_register+0x6c/0x128 [ 2.214355] __platform_driver_register+0x50/0x60 [ 2.219053] fsl_dspi_driver_init+0x24/0x30 [ 2.223229] do_one_initcall+0x4c/0x2c0 [ 2.227058] kernel_init_freeable+0x214/0x280 [ 2.231409] kernel_init+0x1c/0x128 [ 2.234889] ret_from_fork+0x10/0x30 [ 2.238458] Code: 290a7fff f9403c16 b4001094 f94006c0 (f9404000) [ 2.244553] ---[ end trace cec4aea5fb1ac3ec ]--- [ 2.249176] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b [ 2.249618] ata1: SATA link down (SStatus 0 SControl 300) [ 2.256828] SMP: stopping secondary CPUs [ 2.256836] Kernel Offset: 0x573dcf080000 from 0xffff800010000000 [ 2.256837] PHYS_OFFSET: 0xffff8f0ec0000000 [ 2.256839] CPU features: 0x0240022,21806008 [ 2.256840] Memory Limit: none

[ 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 michael@walle.cc Tested-by: Sascha Hauer s.hauer@pengutronix.de Reviewed-by: Krzysztof Kozlowski krzk@kernel.org

---

changes since v2:

• trimmed the commit message, suggested by Krzysztof.

changes since v1:

• moved platform_set_drvdata(), suggested by Krzysztof.

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 a939618f5e47..3967afa465f0 100644 --- a/drivers/spi/spi-fsl-dspi.c +++ b/drivers/spi/spi-fsl-dspi.c @@ -1236,6 +1236,9 @@ 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;
  
  

@@ -1371,8 +1374,6 @@ static int dspi_probe(struct platform_device *pdev) 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");
  

-- 2.20.1

metadata: git branch: master git repo: https://gitlab.com/Linaro/lkft/mirrors/torvalds/linux-mainline git commit: 583090b1b8232e6eae243a9009699666153a13a9 git describe: v5.9-rc8-206-g583090b1b823 make_kernelversion: 5.9.0-rc8 kernel-config: https://builds.tuxbuild.com/hkbjxXyQ2-4IiR2Z-6P8vw/kernel.config

full log link, https://qa-reports.linaro.org/lkft/linux-mainline-master/build/v5.9-rc8-206-...