[PATCH] ARM: keystone: fix platform_domain_notifier array overrun

[Santosh Shilimkar]

On 5/10/2018 6:24 AM, Russell King wrote:
> platform_domain_notifier contains a variable sized array, which the
> pm_clk_notify() notifier treats as a NULL terminated array:
> 
>       for (con_id = clknb->con_ids; *con_id; con_id++)
>               pm_clk_add(dev, *con_id);
> 
> Omitting the initialiser for con_ids means that the array is zero
> sized, and there is no NULL terminator.  This leads to pm_clk_notify()
> overrunning into what ever structure follows, which may not be NULL.
> This leads to an oops:
> 
> Unable to handle kernel NULL pointer dereference at virtual address 0000008c
> pgd = c0003000
> [0000008c] *pgd=80000800004003c, *pmd=00000000c
> Internal error: Oops: 206 [#1] PREEMPT SMP ARM
> Modules linked in:c
> CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.16.0+ #9
> Hardware name: Keystone
> PC is at strlen+0x0/0x34
> LR is at kstrdup+0x18/0x54
> pc : [<c0623340>]    lr : [<c0111d6c>]    psr: 20000013
> sp : eec73dc0  ip : eed780c0  fp : 00000001
> r10: 00000000  r9 : 00000000  r8 : eed71e10
> r7 : 0000008c  r6 : 0000008c  r5 : 014000c0  r4 : c03a6ff4
> r3 : c09445d0  r2 : 00000000  r1 : 014000c0  r0 : 0000008c
> Flags: nzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
> Control: 30c5387d  Table: 00003000  DAC: fffffffd
> Process swapper/0 (pid: 1, stack limit = 0xeec72210)
> Stack: (0xeec73dc0 to 0xeec74000)
> ...
> [<c0623340>] (strlen) from [<c0111d6c>] (kstrdup+0x18/0x54)
> [<c0111d6c>] (kstrdup) from [<c03a6ff4>] (__pm_clk_add+0x58/0x120)
> [<c03a6ff4>] (__pm_clk_add) from [<c03a731c>] (pm_clk_notify+0x64/0xa8)
> [<c03a731c>] (pm_clk_notify) from [<c004614c>] (notifier_call_chain+0x44/0x84)
> [<c004614c>] (notifier_call_chain) from [<c0046320>] (__blocking_notifier_call_chain+0x48/0x60)
> [<c0046320>] (__blocking_notifier_call_chain) from [<c0046350>] (blocking_notifier_call_chain+0x18/0x20)
> [<c0046350>] (blocking_notifier_call_chain) from [<c0390234>] (device_add+0x36c/0x534)
> [<c0390234>] (device_add) from [<c047fc00>] (of_platform_device_create_pdata+0x70/0xa4)
> [<c047fc00>] (of_platform_device_create_pdata) from [<c047fea0>] (of_platform_bus_create+0xf0/0x1ec)
> [<c047fea0>] (of_platform_bus_create) from [<c047fff8>] (of_platform_populate+0x5c/0xac)
> [<c047fff8>] (of_platform_populate) from [<c08b1f04>] (of_platform_default_populate_init+0x8c/0xa8)
> [<c08b1f04>] (of_platform_default_populate_init) from [<c000a78c>] (do_one_initcall+0x3c/0x164)
> [<c000a78c>] (do_one_initcall) from [<c087bd9c>] (kernel_init_freeable+0x10c/0x1d0)
> [<c087bd9c>] (kernel_init_freeable) from [<c0628db0>] (kernel_init+0x8/0xf0)
> [<c0628db0>] (kernel_init) from [<c00090d8>] (ret_from_fork+0x14/0x3c)
> Exception stack(0xeec73fb0 to 0xeec73ff8)
> 3fa0:                                     00000000 00000000 00000000 00000000
> 3fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
> 3fe0: 00000000 00000000 00000000 00000000 00000013 00000000
> Code: e3520000 1afffff7 e12fff1e c0801730 (e5d02000)
> ---[ end trace cafa8f148e262e80 ]---
> 
> Fix this by adding the necessary initialiser.
> 
> Fixes: fc20ffe1213b ("ARM: keystone: add PM domain support for clock management")
> Signed-off-by: Russell King <rmk+kernel at armlinux.org.uk>
> ---
Looks good. Thanks Russell !!
Acked-by: Santosh Shilimkar <ssantosh at kernel.org>

Arnd, olof,
Could you please pick this up for the fixes branch ?