Re: [PATCH] x86/numa: kernel stack corruption fix
From: Dave Young
Date: Fri Apr 03 2015 - 03:15:44 EST
Hi,
On 04/02/15 at 12:36pm, Yasuaki Ishimatsu wrote:
>
> On Wed, 1 Apr 2015 12:53:46 +0800
> Dave Young <dyoung@xxxxxxxxxx> wrote:
>
> > I got below kernel panic during kdump test on Thinkpad T420 laptop:
> >
> > [ 0.000000] No NUMA configuration found
> > [ 0.000000] Faking a node at [mem 0x0000000000000000-0x0000000037ba4fff]
> > [ 0.000000] Kernel panic - not syncing: stack-protector: Kernel stack is cor
> > upted in: ffffffff81d21910 r
> > [ 0.000000]
> > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rc6+ #44
> > [ 0.000000] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET76WW (1.46 ) 07/
> > 5/2013 0
> > [ 0.000000] 0000000000000000 c70296ddd809e4f6 ffffffff81b67ce8 ffffffff817c
> > a26 2
> > [ 0.000000] 0000000000000000 ffffffff81a61c90 ffffffff81b67d68 ffffffff817b
> > 8d2 c
> > [ 0.000000] 0000000000000010 ffffffff81b67d78 ffffffff81b67d18 c70296ddd809
> > 4f6 e
> > [ 0.000000] Call Trace:
> > [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57
> > [ 0.000000] [<ffffffff817bc8d2>] panic+0xd0/0x204
> > [ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2
> > [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20
> > [ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2
> > [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520
> > [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d
> > [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb
> > [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c
> > [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184
> > [ 0.000000] ---[ end Kernel panic - not syncing: stack-protector: Kernel sta
> > k is corrupted in: ffffffff81d21910 c
> > [ 0.000000]
> > PANIC: early exception 0d rip 10:ffffffff8105d2a6 error 7eb cr2 ffff8800371dd00
> > [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.0.0-rc6+ #44 0
> > [ 0.000000] Hardware name: LENOVO 4236NUC/4236NUC, BIOS 83ET76WW (1.46 ) 07/
> > 5/2013 0
> > [ 0.000000] 0000000000000000 c70296ddd809e4f6 ffffffff81b67c60 ffffffff817c
> > a26 2
> > [ 0.000000] 0000000000000096 ffffffff81a61c90 ffffffff81b67d68 fffffff00000
> > 084 0000000000000a0d 0000000000000a00 0
> > [ 0.000000] Call Trace:
> > [ 0.000000] [<ffffffff817c2a26>] dump_stack+0x45/0x57
> > [ 0.000000] [<ffffffff81d051b0>] early_idt_handler+0x90/0xb7
> > [ 0.000000] [<ffffffff8105d2a6>] ? native_irq_enable+0x6/0x10
> > [ 0.000000] [<ffffffff817bc9c5>] ? panic+0x1c3/0x204
> > [ 0.000000] [<ffffffff81d21910>] ? numa_clear_kernel_node_hotplug+0xe6/0xf2
> > [ 0.000000] [<ffffffff8107741b>] __stack_chk_fail+0x1b/0x20
> > [ 0.000000] [<ffffffff81d21910>] numa_clear_kernel_node_hotplug+0xe6/0xf2
> > [ 0.000000] [<ffffffff81d21e5d>] numa_init+0x1a5/0x520
> > [ 0.000000] [<ffffffff81d222b1>] x86_numa_init+0x19/0x3d
> > [ 0.000000] [<ffffffff81d22460>] initmem_init+0x9/0xb
> > [ 0.000000] [<ffffffff81d0d00c>] setup_arch+0x94f/0xc82
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff817bd0bb>] ? printk+0x55/0x6b
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff81d05d9b>] start_kernel+0xe8/0x4d6
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff81d05120>] ? early_idt_handlers+0x120/0x120
> > [ 0.000000] [<ffffffff81d055ee>] x86_64_start_reservations+0x2a/0x2c
> > [ 0.000000] [<ffffffff81d05751>] x86_64_start_kernel+0x161/0x184
> > [ 0.000000] RIP 0x46
> >
> > This is caused by writing over end of numa mask bitmap.
> >
> > numa_clear_kernel_node try to set node id in a mask bitmap, it iterating all
> > reserved region and assume every regions have valid nid. It is not true because
> > There's an exception for graphic memory quirks. see function trim_snb_memory
> > in arch/x86/kernel/setup.c
> >
> > It is easily to reproduce the bug in kdump kernel because kdump kernel use
> > prereserved memory instead of whole memory, but kexec pass other reserved memory
> > ranges to 2nd kernel as well. like below in my test:
> > kdump kernel ram 0x2d000000 - 0x37bfffff
> > One of the reserved regions: 0x40000000 - 0x40100000
> >
> > The above reserved region includes 0x40004000, a page excluded in
> > trim_snb_memory. For this memblock reserved region the nid is not set it is
> > still default value MAX_NUMNODES. later node_set callback will set bit
> > MAX_NUMNODES in nodemask bitmap thus stack corruption happen.
> >
> > Fixing this by adding a check, do not call node_set in case nid is MAX_NUMNODES.
> >
> > Signed-off-by: Dave Young <dyoung@xxxxxxxxxx>
> > ---
>
> Looks good to me.
>
> Reviewed-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Per suggestion from Xishi Qiu, I would like to add below comment in code and repost
Could I carry with your Reviewed-by line?
/* In case booting with numa=off and only using part of system ram
* ie. mem=nn[kMG] or in kdump kernel, numa_meminfo may not include all the
* memblock.reserved memory because trim_snb_memory() reserves specific pages
* for Sandy Bridge graphics. */
Thanks
Dave
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