M1 MacBook Pro constant kernel panic with ANS2 Recoverable Panic :MD_UNCORR_ERR F2H

Run the following Terminal command so we can retrieve the SMART health information from the internal SSD and post the results here (best to copy & paste this since every character is critical):

diskutil info -plist disk0 | plutil -extract "SMARTDeviceSpecificKeysMayVaryNotGuaranteed" json -r - -o -  | grep -v '_1"' 

ANS2 Kernel Panics are related to SSD issues. Usually it will be due to the internal SSD failing, but you may also see these types of Kernel Panics associated with Thunderbolt connected SSDs. I am very curious about the results of this command in regards to these Kernel Panics.

The Kernel Panic is showing "uncorrectable" errors which means the SSD has a hardware problem. With the Intel Macs I have successfully "fixed" SSD issues like this by resetting the SSD to defaults by using the SSD's built-in hardware secure erase feature. With the Apple Silicon Macs, there is no way to do this the same way.

Perhaps a DFU Firmware Restore will reset the built-in SSD to factory defaults, or it may just perform a simple erase which likely won't help fix anything. This is the only option you have to try to attempt to "fix" the internal SSD, otherwise the laptop will need to be repaired by having the Logic Board replaced because the SSD is integrated onto the Logic Board.

Unfortunately a DFU Firmware Restore requires access to another Mac currently running macOS 15.7+ Sequoia, macOS 26.x Tahoe, or macOS 27 Golden Gate (the Apple Configurator app version 2.19 is required if the host Mac is running Sequoia). This process will destroy all data on the internal SSD and it will push a clean copy of macOS onto the internal SSD. Afterwards you can restore from your Time Machine backup during the initial setup of the new OS.

If you do this, then run the Terminal command again to see if the "Media Errors" and "NUM_ERROR_INFO_LOG_ENTRIES_0" values have changed (most likely they should remain the same). I would monitor these values occasionally even if there are no more Kernel Panics just to make sure these values are not increasing. If the DFU Firmware Restore actually reset the internal SSD instead of just performing a simple erase, then hopefully those errors will stop accumulating.

I'm very glad to see you do have backups.

gbaghdik wrote:

Here is the result of this command:

greg@Gregs-MacBook-Pro ~ % diskutil info -plist disk0 | plutil -extract "SMARTDeviceSpecificKeysMayVaryNotGuaranteed" json -r - -o -  | grep -v '_1"'  

{

  "AVAILABLE_SPARE" : 100,

  "AVAILABLE_SPARE_THRESHOLD" : 99,

  "CONTROLLER_BUSY_TIME_0" : 0,

  "DATA_UNITS_READ_0" : 70991415,

  "DATA_UNITS_WRITTEN_0" : 48277170,

  "HOST_READ_COMMANDS_0" : 1401115017,

  "HOST_WRITE_COMMANDS_0" : 1109343037,

  "MEDIA_ERRORS_0" : 0,

  "NUM_ERROR_INFO_LOG_ENTRIES_0" : 0,

  "PERCENTAGE_USED" : 2,

  "POWER_CYCLES_0" : 490,

  "POWER_ON_HOURS_0" : 661,

  "TEMPERATURE" : 309,

  "UNSAFE_SHUTDOWNS_0" : 272,

}

Unfortunately I've already tried a DFU Firmware restore once before. It may have helped temporarily, but I'm not sure if it was something I reinstalled, or a hardware issue that made the kernel panics return.

Thanks for providing this information. I thought we would see some errors on these two health attributes:

  "MEDIA_ERRORS_0" : 0,

  "NUM_ERROR_INFO_LOG_ENTRIES_0" : 0,

Since these two health attributes are not showing any issues, I think your only option is to have the Logic Board replaced especially since you already tried a DFU Firmware Restore.

Convincing Apple or an Apple Authorized Service Provider that replacing the Logic Board is necessary will be your next obstacle since they usually don't understand how to interpret these Kernel Panics. If you can reproduce a Kernel Panic after a DFU Firmware Restore and before restoring from a backup or installing third party software, then it makes it easy for Apple or an AASP to replace the Logic Board. Otherwise you may need to open a support case with Apple and have the case escalated once the basic low level support leads nowhere so Apple will actually examine your Kernel Panic logs.

Here is a post by @Grant Bennet-Alder who explains the process & issues of getting a hardware repair for these types of issues (see the "Technical" section on):

@Grant Bennet-Alder's Tips for Getting Apple to Authorize a Hardware Repair for Kernel Panics - Apple Community

gbaghdik wrote:

Thank you for all this info!

Is a logic board replacement something that Apple would cover the cost of in this situation? I've in the past looked at the official Apple parts site and my board would be something around $1200, $400 after I return the original board, which is pretty expensive..

Only if the device is still under warranty or has the extended AppleCare+ coverage or whatever Apple may be calling it these days. Or if Apple has some secret free repair program for the issue.

For reference, here is the list of Apple's publicly acknowledged free repair programs, but your laptop is not on it:

Apple Service Programs - Apple Support

I've ran Apple diagnostics and it comes back with no errors.

Apple Diagnostics will never find anything that causes a kernel panic.

I have even clean installed MacOS from DFU using a 2nd Mac. This seemed to correct the problem for a while, but eventually the panics returned.

Do they return after having installed some System extension or external hardware?

Why do you have Wireshark installed?

I wasn't able to correlate the kernel panic return with any specific install. Note that I also have brew installed to make it easier to install linux-like tools, that could possibly be a suspect too? When I installed brew and tools like SDR++, GNU Radio, etc, it didn't immediately cause panics...

Panics aren't caused by regular software. Only kernel extensions. External hardware can cause a panic, but I think that is generally associated with a kernel extension installed to handle the hardware. If any of those tools are low-level system modifications, they could possibly trigger a panic.

I use Wireshark to examine traffic on my local network and diagnose network issues. Could the pcap plugin be causing issues?

I don't know. I was wondering if you were using Wireshark to try to resolve some other problem that might be related.

As HWTech noted, in order to get any response out of Apple, you have to demonstrate the panics on a completely clean system without any added software or any external hardware attached.

I wasn't able to correlate the kernel panic return with any specific install. Note that I also have brew installed to make it easier to install linux-like tools, that could possibly be a suspect too? When I installed brew and tools like SDR++, GNU Radio, etc, it didn't immediately cause panics...

I use Wireshark to examine traffic on my local network and diagnose network issues. Could the pcap plugin be causing issues?

Here is the result of this command:

greg@Gregs-MacBook-Pro ~ % diskutil info -plist disk0 | plutil -extract "SMARTDeviceSpecificKeysMayVaryNotGuaranteed" json -r - -o -  | grep -v '_1"'  
{
  "AVAILABLE_SPARE" : 100,
  "AVAILABLE_SPARE_THRESHOLD" : 99,
  "CONTROLLER_BUSY_TIME_0" : 0,
  "DATA_UNITS_READ_0" : 70991415,
  "DATA_UNITS_WRITTEN_0" : 48277170,
  "HOST_READ_COMMANDS_0" : 1401115017,
  "HOST_WRITE_COMMANDS_0" : 1109343037,
  "MEDIA_ERRORS_0" : 0,
  "NUM_ERROR_INFO_LOG_ENTRIES_0" : 0,
  "PERCENTAGE_USED" : 2,
  "POWER_CYCLES_0" : 490,
  "POWER_ON_HOURS_0" : 661,
  "TEMPERATURE" : 309,
  "UNSAFE_SHUTDOWNS_0" : 272,
}

Unfortunately I've already tried a DFU Firmware restore once before. It may have helped temporarily, but I'm not sure if it was something I reinstalled, or a hardware issue that made the kernel panics return.

Thank you for all this info!

Is a logic board replacement something that Apple would cover the cost of in this situation? I've in the past looked at the official Apple parts site and my board would be something around $1200, $400 after I return the original board, which is pretty expensive..