[PATCH RESEND] mfd: mc13xxx: Fix null pointer dereference in mc13xxx_common_init

[Michael Grzeschik]

On Sat, Nov 30, 2013 at 08:55:37AM +0400, Alexander Shiyan wrote:
> If this driver being loaded from devicetree, the pdata is NULL.
> This cause kernel Oops when "fsl,mc13xxx-uses-codec" and/or
> "fsl,mc13xxx-uses-touch" properties is specified.
> 
> mc13xxx spi0.0: mc13783: rev: 3.3, fin: 0, fab: 0, icid: 2/0
> Unable to handle kernel NULL pointer dereference at virtual address 00000018
> pgd = c0004000
> [00000018] *pgd=00000000
> Internal error: Oops: 5 [#1] PREEMPT ARM
> CPU: 0 PID: 1 Comm: swapper Not tainted 3.12.0-next-20131105-00004-g201dd34-dirty #5
> task: c7833bc0 ti: c7834000 task.ti: c7834000
> PC is at mc13xxx_common_init+0x1fc/0x280
> LR is at mfd_add_device+0x2a8/0x308
> pc : [<c024875c>]    lr : [<c0248d74>]    psr: 20000013
> sp : c7835d38  ip : 00000002  fp : c786a160
> r10: 00000000  r9 : c786a170  r8 : 00000000
> r7 : c06eab74  r6 : 00000000  r5 : 00000000  r4 : c79ffa10
> r3 : 00000008  r2 : 20000013  r1 : c05079c8  r0 : c79ffa10
> Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment kernel
> Control: 0005317f  Table: a0004000  DAC: 00000017
> Process swapper (pid: 1, stack limit = 0xc78341c0)
> Stack: (0xc7835d38 to 0xc7836000)
> 5d20:                                                       c0507958 c79ffa10
> 5d40: c791ab80 0000009b 00000000 c791ab80 c05de138 c023a998 c05a9854 c0293cf8
> 5d60: c0293ce0 c023a774 c023a998 00000000 c791ab80 c023a998 c79ffc00 c02393ac
> 5d80: c785a25c c7940e54 c791ab80 c791abb4 c791ab80 c023a4cc c791ab80 c05b2704
> 5da0: c791ab80 c02395e8 c791ab80 00000000 c791ab88 c0237938 00000000 c01d5ed8
> 5dc0: 60000013 c791ab80 c791ab80 c791ab80 00000000 c786a170 00000000 c06eaa04
> 5de0: c786a170 c0294d08 00000001 c79ffc00 c06eab74 c791ab80 00000000 c02953a8
> 5e00: c79f56a0 00000000 00000063 01312d00 00000000 c79ffc00 c79ffd78 c79ffc00
> 5e20: c06eaa04 00000000 c79ffd70 c0296cbc c780a840 c02978c0 00000000 c051054c
> 5e40: c79ffd70 c787c1f0 00000000 c0462b1c 00000000 00000002 c787c1f0 c786a170
> 5e60: c05b2864 c786a1a4 c05b2864 00000000 c05c5800 c0579430 00000000 c023b614
> 5e80: c023b5fc c786a170 c05de138 c023a774 00000000 c786a170 c05b2864 c786a1a4
> 5ea0: 00000000 c023a994 00000000 c05b2864 c023a908 c0239034 c7825d6c c785e610
> 5ec0: c05b2864 c7a0bae0 c05a9138 c02397dc c051054c c01bd2f8 c05b2864 c05b2864
> 5ee0: c0585094 579da752 00000000 c023ad38 00000000 00000006 c0585094 c0564a24
> 5f00: 0000047a 00000000 579da752 00000000 00000000 a0000053 c059b070 00000001
> 5f20: c06eefc9 c044c6a0 000000a7 c002cd48 c7835f5c c0036f44 c051aae4 c053d7f4
> 5f40: 00000006 00000006 c059b064 00000006 00000006 c0585094 c058db68 c0564480
> 5f60: c05850a0 c05c5800 000000a7 c0564c18 00000006 00000006 c0564480 c7833bc0
> 5f80: c7835f9c c0036da4 00000000 c043013c 00000000 00000000 00000000 00000000
> 5fa0: 00000000 c0430144 00000000 c0009490 00000000 00000000 00000000 00000000
> 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 df7f9b78 3b477df6
> [<c024875c>] (mc13xxx_common_init+0x1fc/0x280) from [<c0293cf8>] (spi_drv_probe+0x18/0x1c)
> [<c0293cf8>] (spi_drv_probe+0x18/0x1c) from [<c023a774>] (driver_probe_device+0x78/0x20c)
> [<c023a774>] (driver_probe_device+0x78/0x20c) from [<c02393ac>] (bus_for_each_drv+0x48/0x90)
> [<c02393ac>] (bus_for_each_drv+0x48/0x90) from [<c023a4cc>] (device_attach+0x74/0x80)
> [<c023a4cc>] (device_attach+0x74/0x80) from [<c02395e8>] (bus_probe_device+0x88/0xb0)
> [<c02395e8>] (bus_probe_device+0x88/0xb0) from [<c0237938>] (device_add+0x31c/0x4c4)
> [<c0237938>] (device_add+0x31c/0x4c4) from [<c0294d08>] (spi_add_device+0xa4/0x118)
> [<c0294d08>] (spi_add_device+0xa4/0x118) from [<c02953a8>] (spi_register_master+0x53c/0x6a0)
> [<c02953a8>] (spi_register_master+0x53c/0x6a0) from [<c0296cbc>] (spi_bitbang_start+0x88/0x100)
> [<c0296cbc>] (spi_bitbang_start+0x88/0x100) from [<c02978c0>] (spi_imx_probe+0x3a8/0x478)
> [<c02978c0>] (spi_imx_probe+0x3a8/0x478) from [<c023b614>] (platform_drv_probe+0x18/0x48)
> [<c023b614>] (platform_drv_probe+0x18/0x48) from [<c023a774>] (driver_probe_device+0x78/0x20c)
> [<c023a774>] (driver_probe_device+0x78/0x20c) from [<c023a994>] (__driver_attach+0x8c/0x90)
> [<c023a994>] (__driver_attach+0x8c/0x90) from [<c0239034>] (bus_for_each_dev+0x5c/0x8c)
> [<c0239034>] (bus_for_each_dev+0x5c/0x8c) from [<c02397dc>] (bus_add_driver+0xd4/0x1c8)
> [<c02397dc>] (bus_add_driver+0xd4/0x1c8) from [<c023ad38>] (driver_register+0x78/0xf4)
> [<c023ad38>] (driver_register+0x78/0xf4) from [<c0564a24>] (do_one_initcall+0x5c/0x168)
> [<c0564a24>] (do_one_initcall+0x5c/0x168) from [<c0564c18>] (kernel_init_freeable+0xe8/0x1a8)
> [<c0564c18>] (kernel_init_freeable+0xe8/0x1a8) from [<c0430144>] (kernel_init+0x8/0x110)
> [<c0430144>] (kernel_init+0x8/0x110) from [<c0009490>] (ret_from_fork+0x14/0x24)
> Code: eaffffdb e3a03008 e1a00004 e59f107c (e5962018)
> ---[ end trace 71265dd116f3967e ]---
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
> 
> Signed-off-by: Alexander Shiyan <shc_work at mail.ru>
> ---
>  drivers/mfd/mc13xxx-core.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/mfd/mc13xxx-core.c b/drivers/mfd/mc13xxx-core.c
> index dbbf8ee..625633a 100644
> --- a/drivers/mfd/mc13xxx-core.c
> +++ b/drivers/mfd/mc13xxx-core.c
> @@ -682,14 +682,14 @@ err_revision:
>  	if (mc13xxx->flags & MC13XXX_USE_ADC)
>  		mc13xxx_add_subdevice(mc13xxx, "%s-adc");
>  
> -	if (mc13xxx->flags & MC13XXX_USE_CODEC)
> +	if ((mc13xxx->flags & MC13XXX_USE_CODEC) && pdata)
>  		mc13xxx_add_subdevice_pdata(mc13xxx, "%s-codec",
>  					pdata->codec, sizeof(*pdata->codec));
>  
>  	if (mc13xxx->flags & MC13XXX_USE_RTC)
>  		mc13xxx_add_subdevice(mc13xxx, "%s-rtc");
>  
> -	if (mc13xxx->flags & MC13XXX_USE_TOUCHSCREEN)
> +	if ((mc13xxx->flags & MC13XXX_USE_CODEC) && pdata)

Why do we check for CODEC if the Touchscreen should be used?

>  		mc13xxx_add_subdevice_pdata(mc13xxx, "%s-ts",
>  				&pdata->touch, sizeof(pdata->touch));
>  
> @@ -701,6 +701,10 @@ err_revision:
>  		mc13xxx_add_subdevice_pdata(mc13xxx, "%s-pwrbutton",
>  				pdata->buttons, sizeof(*pdata->buttons));
>  	} else {
> +		if (mc13xxx->flags & MC13XXX_USE_CODEC)
> +			mc13xxx_add_subdevice(mc13xxx, "%s-codec");
> +		if (mc13xxx->flags & MC13XXX_USE_TOUCHSCREEN)
> +			mc13xxx_add_subdevice(mc13xxx, "%s-ts");
>  		mc13xxx_add_subdevice(mc13xxx, "%s-regulator");
>  		mc13xxx_add_subdevice(mc13xxx, "%s-led");
>  		mc13xxx_add_subdevice(mc13xxx, "%s-pwrbutton");
> -- 
> 1.8.3.2
> 
> 

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