[PATCH] ARM: keystone: fix platform_domain_notifier array overrun

[Olof Johansson]

On Thu, May 10, 2018 at 10:55:39AM -0700, Santosh Shilimkar wrote:
> 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 ?

Applied to fixes. Thanks!


-Olof