# After Update from 4.1.15 --> 4.4.6 = Corrupted low memory ?!

## SarahS93

After Update from 4.1.15 to 4.4.6 dmesg shows me "Corrupted low memory" message:

```
[  540.904754] Corrupted low memory at ffff88000000a000 (a000 phys) = 00020a0e

[  540.904763] ------------[ cut here ]------------

[  540.904772] WARNING: CPU: 5 PID: 725 at arch/x86/kernel/check.c:141 check_for_bios_corruption+0xb9/0x110()

[  540.904774] Memory corruption detected in low memory

[  540.904775] Modules linked in: nvidia(PO) x86_pkg_temp_thermal

[  540.904782] CPU: 5 PID: 725 Comm: kworker/5:1 Tainted: P           O    4.4.6-gentoo #1

[  540.904784] Hardware name: Gigabyte Technology Co., Ltd. P67A-UD4-B3/P67A-UD4-B3, BIOS F8 03/21/2012

[  540.904788] Workqueue: events check_corruption

[  540.904790]  0000000000000000 ffff8804183e3d30 ffffffff8148f368 ffff8804183e3d78

[  540.904794]  ffffffff81e345e5 ffff8804183e3d68 ffffffff810d7111 0000000000000000

[  540.904796]  ffff880000010000 ffffffff82295690 0000000000000001 ffff880000000000

[  540.904800] Call Trace:

[  540.904806]  [<ffffffff8148f368>] dump_stack+0x4d/0x65

[  540.904810]  [<ffffffff810d7111>] warn_slowpath_common+0x81/0xc0

[  540.904812]  [<ffffffff810d7197>] warn_slowpath_fmt+0x47/0x50

[  540.904816]  [<ffffffff8108f949>] check_for_bios_corruption+0xb9/0x110

[  540.904819]  [<ffffffff8108f9a9>] check_corruption+0x9/0x40

[  540.904823]  [<ffffffff810ecece>] process_one_work+0x14e/0x400

[  540.904825]  [<ffffffff810ed496>] worker_thread+0x46/0x440

[  540.904837]  [<ffffffff81a492b5>] ? __schedule+0x355/0x9c0

[  540.904838]  [<ffffffff810ed450>] ? rescuer_thread+0x2d0/0x2d0

[  540.904839]  [<ffffffff810ed450>] ? rescuer_thread+0x2d0/0x2d0

[  540.904841]  [<ffffffff810f20f4>] kthread+0xc4/0xe0

[  540.904842]  [<ffffffff810f2030>] ? kthread_park+0x50/0x50

[  540.904844]  [<ffffffff81a4d3df>] ret_from_fork+0x3f/0x70

[  540.904845]  [<ffffffff810f2030>] ? kthread_park+0x50/0x50

[  540.904846] ---[ end trace a20df8e27195da9a ]---
```

Syslog show me messages too

```
Jun  3 22:56:25 deruse kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 000736ba

Jun  3 22:58:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 00082ca5

Jun  3 23:01:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 000960b2

Jun  3 23:04:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 000ac377

Jun  3 23:06:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 000f5bbf

Jun  3 23:07:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 00150fa1

Jun  3 23:08:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 0017c2e5

Jun  3 23:10:25 pc1 kernel: Corrupted low memory at ffff88000000a000 (a000 phys) = 001e13d8
```

Anything wrong with my Hardware?

What have i to do?

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## Ant P.

This comes from CONFIG_X86_CHECK_BIOS_CORRUPTION=y in the processor type menu. If you already have CONFIG_X86_RESERVE_LOW set to its default value, you don't need to do anything and can turn the first option off.

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## khayyam

SarahS93 ...

given that this is "disabled at runtime" (see: help/"?" for this item in menuconfig) and so requires that "memory_corruption_check=1" be set, it is probably a bug. Try the following, either set CONFIG_X86_CHECK_BIOS_CORRUPTION=n (Processor type and features => Check for low memory corruption) and rebuild the kernel, or set 'memory_corruption_check=0' as a kernel parameter (ie, via grub.cfg).

I don't think there is anything is wrong with your hardware/memory, its the driver which seems to be causing the issue (as again, the driver shouldn't be active unless explictly provided 'memory_corruption_check=1').

HTH & best ... khay

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