Brand new 2020 5K iMac kernel panic

[AppleGeek1127]

I haven't seen a kernel panic on a Mac for probably 10 years. Yet my brand new iMac has given me several in the few days I have owned it. Here is the verbose output of the last one. Any idea what this means?

panic(cpu 4 caller 0xffffff80151cf223): "Possible memory corruption: pmap_pv_remove(0xffffff86e47b2580,0x10d489000,0x42826c): " "empty hash, removing rooted, priors: 0"@/AppleInternal/BuildRoot/Library/Caches/com.apple.xbs/Sources/xnu/xnu-7195.50.7/osfmk/i386/pmap_internal.h:936
Backtrace (CPU 4), Frame : Return Address
0xffffffa0c1b63900 : 0xffffff80150bc66d
0xffffffa0c1b63950 : 0xffffff80151ff073
0xffffffa0c1b63990 : 0xffffff80151ef6aa
0xffffffa0c1b639e0 : 0xffffff8015061a2f
0xffffffa0c1b63a00 : 0xffffff80150bbf0d
0xffffffa0c1b63b20 : 0xffffff80150bc1f8
0xffffffa0c1b63b90 : 0xffffff80158bee1a
0xffffffa0c1b63c00 : 0xffffff80151cf223
0xffffffa0c1b63ce0 : 0xffffff80151cf456
0xffffffa0c1b63d40 : 0xffffff801515c4d5
0xffffffa0c1b63e90 : 0xffffff801515be23
0xffffffa0c1b63ec0 : 0xffffff80150add5e
0xffffffa0c1b63ef0 : 0xffffff80151d3823
0xffffffa0c1b63fa0 : 0xffffff8015062216

Process name corresponding to current thread: com.apple.Safari.History
Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version:
20B29

Kernel version:
Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASE_X86_64
Kernel UUID: 84C6DC45-6B02-335F-9439-5D2A9BC385A4
KernelCache slide: 0x0000000014e00000
KernelCache base: 0xffffff8015000000
Kernel slide: 0x0000000014e10000
Kernel text base: 0xffffff8015010000
__HIB text base: 0xffffff8014f00000
System model name: iMac20,2 (Mac-AF89B6D9451A490B)
System shutdown begun: NO
Hibernation exit count: 0

System uptime in nanoseconds: 262275839448
Last Sleep: absolute base_tsc base_nano
Uptime : 0x0000003d10dbb7e1
Sleep : 0x0000000000000000 0x0000000000000000 0x0000000000000000
Wake : 0x0000000000000000 0x000000051d6868e6 0x0000000000000000
last started kext at 112355805557: @filesystems.smbfs 3.4.1 (addr 0xffffff7fb54b5000, size 434176)
loaded kexts:
@filesystems.smbfs 3.4.1
>!ATopCaseHIDEventDriver 4000.27
>!APlatformEnabler 2.7.0d0
>AGPM 119
>X86PlatformShim 1.0.0
@filesystems.autofs 3.0
>!AHIDALSService 1
@fileutil 20.036.15
>!AUpstreamUserClient 3.6.8
@kext.AMDRadeonX6000 4.0.0
@kext.AMDRadeonServiceManager 4.0.0
>!AGraphicsDevicePolicy 6.1.27
@AGDCPluginDisplayMetrics 6.1.27
>pmtelemetry 1
>LuaHardwareAccess 1.0.16
|IOUserEthernet 1.0.1
>usb.!UUserHCI 1
|IO!BSerialManager 8.0.1f5
@Dont_Steal_Mac_OS_X 7.0.0
>!AHV 1
>!ADiskImages2 1
>AGDCBacklightControl 6.1.27
>!ABacklight 180.3
>!AGFXHDA 100.1.431
>!A!IKBLGraphics 16.0.0
>!AThunderboltIP 4.0.3
>BridgeAudioCommunication 100.2
>!AFIVRDriver 4.1.0
>!ABridgeAudio!C 100.2
>!AMCCSControl 1.14
>!A!IPCHPMC 2.0.1
>ACPI_SMC_PlatformPlugin 1.0.0
>!AMuxControl2 6.1.27
>!A!ICFLGraphicsFramebuffer 16.0.0
>!AAVEBridge 6.1
>!A!ISlowAdaptiveClocking 4.0.0
|SCSITaskUserClient 436.40.6
>!UCardReader 511.40.9
>BCMWLANFirmware4378.Hashstore 1
>BCMWLANFirmware4377.Hashstore 1
>BCMWLANFirmware4364.Hashstore 1
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>!ABCMWLANBusInterfacePCIeMac 1
|!ABCM5701Ethernet 11.0.0
>!AFileSystemDriver 3.0.1
@filesystems.tmpfs 1
@filesystems.hfs.kext 556.41.1
@BootCache 40
@!AFSCompression.!AFSCompressionTypeZlib 1.0.0
@!AFSCompression.!AFSCompressionTypeDataless 1.0.0d1
@filesystems.apfs 1677.50.1
@private.KextAudit 1.0
>!AACPIButtons 6.1
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@nke.applicationfirewall 310
|IOKitRegistryCompatibility 1
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>!AMultitouchDriver 4400.28
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@kext.triggers 1.0
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@kext.AMDRadeonX6200HWLibs 1.0
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@kext.AMDSupport 4.0.0
|IO!BHost!CUARTTransport 8.0.1f5
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>!ASMBusPCI 1.0.14d1
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@vecLib.kext 1.2.0
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>!AOnboardSerial 1.0
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@!AGraphicsDeviceControl 6.1.27
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>usb.IOUSBHostHIDDevice 1.2
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[wilberforce]

You are not by any chance running 4 sticks of OWC RAM?
There are several (many?) reports of kernel panics for people running 4 sticks of OWC RAM in 2020 iMac. Maybe just coincidence.
Just checking

 

[AppleGeek1127]

You are not by any chance running 4 sticks of OWC RAM?
There are several (many?) reports of kernel panics for people running 4 sticks of OWC RAM in 2020 iMac. Maybe just coincidence.
Just checking

2 sticks of OWC RAM...

 

[xgman]

maybe try trashing the contents of your user name/Library/Caches and see how things go.

 

[decypher44]

You are not by any chance running 4 sticks of OWC RAM?
There are several (many?) reports of kernel panics for people running 4 sticks of OWC RAM in 2020 iMac. Maybe just coincidence.
Just checking

Man, I'm running 4 OWC. So far, so good. But now you got me worried! I've been running them for about 6 weeks. Currently knocking on wood...

 

[Hulip]

Man, I'm running 4 OWC. So far, so good. But now you got me worried! I've been running them for about 6 weeks. Currently knocking on wood...

I've had no problems with my 4 OWC (64 gigs) either but yes, this has me worried. Perhaps anyone with problems should try contacting OWC to see if that is actually the issue?

Another thought is which brand name is on the stick? Mine says Hynix.

 

[decypher44]

I've had no problems with my 4 OWC (64 gigs) either but yes, this has me worried. Perhaps anyone with problems should try contacting OWC to see if that is actually the issue?

Another thought is which brand name is on the stick? Mine says Hynix.

I'll try to take a look at mine this weekend (been busy dealing with the CA Unemployment Dept - fun!). I can't remember what they said when I installed them. I'm also wondering if it is more correlation than causation. I looked it up earlier and I saw there were some panics related to the graphics card, and something else. Plus, I'm thinking if they've been ok for this long now, they will probably be ok.

 

[dspdoc]

64 GB OWC here. So far no issues. Knock on wood.

 

[nambuccaheadsau]

The issue seems to be when adding after sales memory and leaving the original in place. If you have upgraded the memory, remove the original and see what happens.

 

[decypher44]

The issue seems to be when adding after sales memory and leaving the original in place. If you have upgraded the memory, remove the original and see what happens.

OP, did you mix your memory, or just OWC? Nambuccaheadsau is correct. Bad to mix Apple memory with aftermarket memory.

 

[Ethosik]

The issue seems to be when adding after sales memory and leaving the original in place. If you have upgraded the memory, remove the original and see what happens.

I am getting these again after I dealt with them for months with the Catalina launch. I have spoken to Apple directly about this and it was confirmed to be a GPU driver issue. Proof of this was I used a 5700XT as an eGPU and the Kernel Panics completely stopped. I still checked every week or two to see if the issue is resolved by disconnecting my eGPU, and 15 minutes later - boom Kernel Panic. It never happened with Mojave, so it was a Catalina problem. Apple confirmed this, and it was fixed on the .5 version of Catalina. I am getting this again on Big Sur, I bet they did not include the patch in the Big Sur codebase or something to that effect.

Your use case might be different that is a problem with faulty RAM, but for my case it was confirmed to be the GPU to be a problem - drivers not hardware.