Re: [PATCH v3] spi: fsl-dspi: fix NULL pointer dereference

From: Naresh Kamboju
Date: Fri Oct 09 2020 - 07:01:41 EST


On Mon, 28 Sep 2020 at 14:26, Michael Walle <michael@xxxxxxxx> 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@xxxxxxxx>
> Tested-by: Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>
> Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> ---
> 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-g583090b1b823/testrun/3283416/suite/linux-log-parser/test/check-kernel-oops-91954/log


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