Roon causes kernel PANIC on Mac Big Sur [resolved: network driver, not Roon]

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1

Hi All,

Before I start let me explain that I have been investigating this issue I have on my Mac for 6 months, since I updated to Big Sur macOS 11.x. I have reinstalled and by process of elimination determined that the ONLY difference I have made to my system that has stopped the kernel panics is NOT RUNNING ROON. Note that my Mac (Intel i9 iMac) is running the Roon Core with my media on a QNAP NAS. I have other Macs running Roon bridge on Big Sur that have no such problems.

Also, I’m an electrical engineer and used to develop kernel drivers for a living on multiple platforms. So before someone says “a user space application cannot possibly cause a kernel panic”. Yes I understand that (unless Roon installs a kernel component) the application itself in user space cannot cause a kernel panic. That’s why operating system have a kernel. However the fact remains if I have Roon running I get kernel panics. Sometimes even if I’m not actually playing music (in the middle of the night). But does happen more frequently when I’m playing music.

So while the fault might lay with Apple, there is something about how Roon interacts with the system that causes the kernel panic to manifest.

So a few facts:

  • Only started happening after I updated to Bug Sur
  • Happens every few days if not using Roon much
  • Can happen several times a day if using Roon (randomly)
  • macOS updated to 11.4 (latest)
  • Music access via SMB mount Music folder
  • Have tried SMB and AFP mounts
  • Mac is on Ethernet and WiFi
  • NAS is on Ethernet
  • I’ve done numerous disk checks (all ok)
  • Re-installing the OS did not help

The Panic message is the following: (and its always the same error)

panic(cpu 2 caller 0xffffff801cc737da): "m_free: freeing an already freed mbuf"@/System/Volumes/Data/SWE/macOS/BuildRoots/e90674e518/Library/Caches/com.apple.xbs/Sources/xnu/xnu-7195.121.3/bsd/kern/uipc_mbuf.c:4820
Backtrace (CPU 2), Frame : Return Address
0xffffffa15b4c3a70 : 0xffffff801c68e0dd 
0xffffffa15b4c3ac0 : 0xffffff801c7d4f33 
0xffffffa15b4c3b00 : 0xffffff801c7c552a 
0xffffffa15b4c3b50 : 0xffffff801c632a2f 
0xffffffa15b4c3b70 : 0xffffff801c68d8fd 
0xffffffa15b4c3c90 : 0xffffff801c68dbf3 
0xffffffa15b4c3d00 : 0xffffff801ce9d81a 
0xffffffa15b4c3d70 : 0xffffff801cc737da 
0xffffffa15b4c3e00 : 0xffffff801eee869f 
0xffffffa15b4c3e20 : 0xffffff801ef1e8e8 
0xffffffa15b4c3e50 : 0xffffff801ef10b4f 
0xffffffa15b4c3e80 : 0xffffff801c6d46c5 
0xffffffa15b4c3ef0 : 0xffffff801c6d5634 
0xffffffa15b4c3fa0 : 0xffffff801c63213e 
      Kernel Extensions in backtrace:
         com.apple.iokit.IONetworkingFamily(3.4)[B6F28D28-0733-3358-B9F0-0825BE36BD88]@0xffffff801eede000->0xffffff801eef4fff
         com.apple.iokit.AppleBCM5701Ethernet(11.0)[329C92EC-5105-3A1E-AA56-B00FD389B51D]@0xffffff801ef0c000->0xffffff801ef2ffff
            dependency: com.apple.driver.mDNSOffloadUserClient(1.0.1b8)[79AE6F06-4E08-37E8-8509-61104903CF66]@0xffffff801f164000->0xffffff801f168fff
            dependency: com.apple.iokit.IOACPIFamily(1.4)[1B2FE91E-3EC7-3ED3-AF6B-E9C4BE29D5E3]@0xffffff801ec42000->0xffffff801ec43fff
            dependency: com.apple.iokit.IONetworkingFamily(3.4)[B6F28D28-0733-3358-B9F0-0825BE36BD88]@0xffffff801eede000->0xffffff801eef4fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff801f16a000->0xffffff801f192fff
            dependency: com.apple.iokit.IOTimeSyncFamily(985.2)[5DDE1DBA-D152-3ED9-B6ED-1612F6A8BE88]@0xffffff801f3b8000->0xffffff801f3d3fff

I’ve seen mention of other kernel panics here, but possibly not this exact error. Any ideas welcome. My plan is to migrate the core to a ROCK once I can find a NUC.

I’ve left Roon not running now for many days and its stable as can be. I’ll update this thread with heartfelt apologies if I do still get a crash but so far its good.

The stack trace about implies it could be an incompatibility with the Ethernet interface. But this could be a red herring and it could be deeper in the IP stack. I have no networking issues with any other application.

Another point of interest, Roon appears to mange its own mount point here:

/Users/<user>/Library/RoonMounts/RoonStorage_<guid>

Is this in any way non-standard. It’s using SMB.

2

I don’t know about Mac, but generally I believe user level application can (indirectly) cause low level issues by triggering a driver level problem for audio / network / graphics / disk, etc.

For your case, I suggest trying having the music library on a USB drive attached to your Roon Core, and remove all watched network folders and remove all network mount points if possible.

3

What Mac? It looks like your network driver is crashing.

1 Like
4

Hi Peter,
yes that would probably work, but if I had to use Roon like that I would not have paid the money for it.
I really have an expectation of using the software in the supported configuration. I’m done debugging other people’s software.

5

2019 27" 5K iMac 3.6 GHz i9:

https://everymac.com/systems/apple/imac/specs/imac-core-i9-3.6-27-inch-aluminum-retina-5k-early-2019-specs.html
Has a 512GB SSD and 8GB + 32GB (40GB) RAM

6

I think Danny has hit the nail on the head!!!

Last night my iMac panic’ed again with the same crash and Roon was not running. It took almost 4 days but the error was there.

So after it rebooted I run Wireshark on the Ethernet interface and discovered a lot of restarts on socket connections, indicative of the high level TCP protocol having to compensate for low level data loss. An ethernet problem at the hardware level. The following is a filtered trace from the Ethernet interface with IP addresses obscured.

image
image1111×875 250 KB

For now I will run just on WiFi and monitor the performance and stability. I’ll run Roon and everything to give it a work out. Plus my wife is working on it during the day. I also have a USB-C to Ethernet adapter (D-Link) so after a few days I may try that one too.

The machine is about 2 years old and I don’t have apple care. I did log this issue with Apple earlier in the year. I’m hopeful they will realise this is probably an issue the machine has had since the factory. It was jus the new drivers as part of Big Sur that have exposed the issue. In fact thinking back, I was occasionally getting pops and dropouts on Roon even before the Big Sur update.

Thanks all for the input.

1 Like