Big Sur panic when connect/disconnect usb-c dock

@DelGurth mine has AMD Radeon Pro 5300M 4 GB yes

Crash fixed in macOS 12 Monterey beta 2

Little bugs: If I use multiport adapter – I see black screen only on external display (NEC 231WMi). On different external display multiport work ok. If I use non–apple dock and the laptop turns on from sleep mode I see black screen on external display (NEC 231WMi) too, but I can reconnect non–apple dock and I see correct external display working. Apple, please fix this bugs with external display too. Also appeared starting from macos 11.3 to 12 beta 2.

Has anyone tested the Big Sur 11.5 Beta 3 release?

Can confirm - have Radeon pro 5600M 8gb. It does it with Displayport and HDMI on my system. I'm guessing they'll not bother till MacOS Monterey - which has been my experience with EGPU and weird issues like this in the past when they're hard at work on a new OS.

Not great - it's been going on for ages. Hardly what you'd expect when you pay the Apple premium for high end hardware

Big Sur 11.5 beta 4... anyone?

In my case it crashes reproducible if I connect the USB-C hub that has two external monitors connected (either both via HDMI or 1 HDMI and 1 DisplayPort doesn't really matter).

Note: The USB-C hub has two HDMI ports and one DisplayPort, so I can try all kinds of combinations. It also has two USB-C ports for connecting (both) to the MacBook.

It doesn't crash though if one monitor is connected via the USB-C hub and I connect the other monitor directly to one of the MacBook's ports with a USB-C-to-DisplayPort cable.

Sadly, I have the same issue, with a Kensington SD5600T dock, with two 4K external monitors.

Usually, I can get the laptop to boot and both monitors to power on and display an image (not always, though). All it takes to get a crash is to disconnect the Thunderbolt cable and connect it again. I have no issues if I connect the monitors directly to the laptop.

{"caused_by":"macos","macos_version":"Mac OS X 11.4 (20F71)","os_version":"Bridge OS 5.4 (18P4663)","macos_system_state":"running","incident_id":"A55327BC-9C3D-4287-A718-9E95DC783DB8","timestamp":"2021-07-01 08:39:39.00 +0000","bug_type":"210"}
{
  ...
  "build" : "Bridge OS 5.4 (18P4663)",
  "crashReporterKey" : "c0dec0dec0dec0dec0dec0dec0dec0dec0de0001",
  "date" : "2021-07-01 08:39:39.76 +0000",
  "incident" : "A55327BC-9C3D-4287-A718-9E95DC783DB8",
  "kernel" : "Darwin Kernel Version 20.5.0: Fri May  7 22:04:14 PDT 2021; root:xnu-7195.121.3~8\/RELEASE_ARM64_T8010",
  "macOSOtherString" : "\n** In Memory Panic Stackshot Succeeded ** Bytes Traced 400304 (Uncompressed 988640) **\n",
  "macOSPanicFlags" : "0xc",
  "macOSPanicString" : "panic(cpu 1 caller 0xffffff801c09f846): [kext.kalloc.2048]: element modified after free (off:1584, val:0x0000210100000000, sz:2048, ptr:0xffffff937950b000, prot:zero)\n 1584: 0x0000210100000000\n 1592: 0x0000000b00000c00\n 1600: 0x000000010000000d\n 1608: 0x0000061f00000000\n 1616: 0x0000028a00000154\n 1624: 0x0000001000000a00\nBacktrace (CPU 1), Frame : 
...
"panicFlags" : "0x902",
  "panicString" : "panic(cpu 1 caller 0xfffffff011488190): macOS panic detected\nDebugger message: panic\nMemory ID: 0x6\nOS release type: User\nOS version: 18P4663\nmacOS version: 20F71\nKernel version: Darwin Kernel Version 20.5.0: Fri May  7 22:04:14 PDT 2021; root:xnu-7195.121.3~8\/REL
EASE_ARM64_T8010\nKernel UUID: 873F4AC5-B66C-3016-8EAC-39D538EEB5A3\niBoot version: iBoot-6723.120.36\nsecure boot?: YES\nx86 EFI Boot State: 0x16\nx86 System State: 0x0\nx86 Power State: 0x0\nx86 Shutdown Cause: 0xf5\nx86 Previous Power Transitions: 0x70707060400\nPCIeUp link state: 0x892
71614\nPaniclog version: 13\nKernel slide:      0x000000000952c000\n
...

I get the same issue on Dell WD19TB docking station on Macbook pro 16 inch running Big Sur 11.4

No workaround so far

panic(cpu 2 caller 0xffffff8016a9f846): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff937493b800, prot:zero)
 1672: 0xfffffffe00000000
Backtrace (CPU 2), Frame : Return Address
0xffffffb0e1c5acf0 : 0xffffff801628e0dd 
0xffffffb0e1c5ad40 : 0xffffff80163d4f33 
0xffffffb0e1c5ad80 : 0xffffff80163c552a 
0xffffffb0e1c5add0 : 0xffffff8016232a2f 
0xffffffb0e1c5adf0 : 0xffffff801628d8fd 
0xffffffb0e1c5af10 : 0xffffff801628dbf3 
0xffffffb0e1c5af80 : 0xffffff8016a9d81a 
0xffffffb0e1c5aff0 : 0xffffff8016a9f846 
0xffffffb0e1c5b470 : 0xffffff80162ecad6 
0xffffffb0e1c5b4e0 : 0xffffff801629d6bc 
0xffffffb0e1c5b530 : 0xffffff80169ae4f2 
0xffffffb0e1c5b550 : 0xffffff7fb06f8fce 
0xffffffb0e1c5b600 : 0xffffff7fb06f965e 
0xffffffb0e1c5b640 : 0xffffff7fb06b9d86 
0xffffffb0e1c5b660 : 0xffffff7fb0ff3e78 
0xffffffb0e1c5b900 : 0xffffff7fb06ba924 
0xffffffb0e1c5b930 : 0xffffff7fb0ff5074 
0xffffffb0e1c5b9c0 : 0xffffff7fb0ff30f7 
0xffffffb0e1c5ba10 : 0xffffff7fb0ff2ee7 
0xffffffb0e1c5ba60 : 0xffffff7fb0ff1f99 
0xffffffb0e1c5baa0 : 0xffffff8016a1e13e 
0xffffffb0e1c5baf0 : 0xffffff7fb06ba5e2 
0xffffffb0e1c5bb20 : 0xffffff8016a2837b 
0xffffffb0e1c5bc80 : 0xffffff8016380961 
0xffffffb0e1c5bd90 : 0xffffff801629375d 
0xffffffb0e1c5be00 : 0xffffff8016269cf5 
0xffffffb0e1c5be60 : 0xffffff8016281312 
0xffffffb0e1c5bef0 : 0xffffff80163a982d 
0xffffffb0e1c5bfa0 : 0xffffff8016233216 
      Kernel Extensions in backtrace:
         com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7fb0fae000->0xffffff7fb1018fff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff80178c0000->0xffffff80178d5fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7fb112f000->0xffffff7fb115dfff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff8018d6a000->0xffffff8018d92fff
            dependency: com.apple.iokit.IOReportFamily(47)[367CCAE7-DAB4-3424-B191-44044619D5CB]@0xffffff8018da1000->0xffffff8018da3fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff8018e94000->0xffffff8018eb0fff
         com.apple.driver.AppleIntelKBLGraphics(16.0.4)[F7BCF586-AF08-3277-9C66-04F439E684B4]@0xffffff7fb06a3000->0xffffff7fb075afff
            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7fb0fae000->0xffffff7fb1018fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7fb112f000->0xffffff7fb115dfff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff8018d6a000->0xffffff8018d92fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff8018e94000->0xffffff8018eb0fff

Process name corresponding to current thread: TouchBarServer
Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version:
20F71

Kernel version:
Darwin Kernel Version 20.5.0: Sat May  8 05:10:33 PDT 2021; root:xnu-7195.121.3~9/RELEASE_X86_64
Kernel UUID: 52A1E876-863E-38E3-AC80-09BBAB13B752
KernelCache slide: 0x0000000016000000
KernelCache base:  0xffffff8016200000
Kernel slide:      0x0000000016010000
Kernel text base:  0xffffff8016210000
__HIB  text base: 0xffffff8016100000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 20

System uptime in nanoseconds: 73757520514384
Last Sleep:           absolute           base_tsc          base_nano
  Uptime  : 0x0000431502cf50a0
  Sleep   : 0x000040654b0930dd 0x0000570283f01b4a 0x00004058bc1cc29a
  Wake    : 0x0000406587fda601 0x00005f776a0abd50 0x00004065674dd451
last started kext at 70335722390424: >!AWWANSupport1	4.0.0 (addr 0xffffff7fb11c2000, size 20480)
last stopped kext at 71105444164574: >AudioAUUC	1.70 (addr 0xffffff7fb0e20000, size 12288)

Same issue here, this is currently messing up my workday where I sometimes need to connect/disconnect monitors multiple times a day.

Been having the same crash as everyone. I noticed a pattern, The crash seems to happen at Idle times, and a few times I noticed the mouse froze when coming back to the mac moving the mouse around seems to unfreeze the mac. I ordered a "VAYDEER Tiny Mouse Jiggler USB" which causes your cursor to constantly move when you have it on (Assuming any juggler that has the cursors moving constantly will work). Every time I leave the Mac I turn it the "Mouse Jiggler" and for the last week I have not had a Kernel Panic, normally had them a few times a day. Not sure what this proves but I think something on the Mac tries to go to sleep when it is Idle it crashes. If anyone else has a mouse jiggle can you try this and see if it make a difference??

Exact same system as you, Belkin Thunderbolt 3 Pro dock here. Same symptoms on 11.4.

I've had the logic board in this machine replaced twice now, bugs logged with Apple support etc. It's very easy to reproduce as others say.

This, in addition to the ethernet driver not working as of Big Sur is another reason I think Apple's QC is going down the pan. Totally unacceptable to have this critical bug in a release OS.

HI ,

Same issue here when I am connecting to my MCP 16 BigSur 11.4 my Docking station my laptop panic and reboot him self it didn't happened the las version before only now .

any update on it. ?

panic(cpu 8 caller 0xffffff8003c9f846): [kext.kalloc.2048]: element modified after free (off:1672, val:0xffffffff00000000, sz:2048, ptr:0xffffff9362ecd000, prot:zero) 1672: 0xffffffff00000000 Backtrace (CPU 8), Frame : Return Address 0xffffffb0cacbab60 : 0xffffff800348e0dd 0xffffffb0cacbabb0 : 0xffffff80035d4f33 0xffffffb0cacbabf0 : 0xffffff80035c552a 0xffffffb0cacbac40 : 0xffffff8003432a2f 0xffffffb0cacbac60 : 0xffffff800348d8fd 0xffffffb0cacbad80 : 0xffffff800348dbf3 0xffffffb0cacbadf0 : 0xffffff8003c9d81a 0xffffffb0cacbae60 : 0xffffff8003c9f846 0xffffffb0cacbb2e0 : 0xffffff80034ecad6 0xffffffb0cacbb350 : 0xffffff800349d6bc 0xffffffb0cacbb3a0 : 0xffffff8003bae4f2 0xffffffb0cacbb3c0 : 0xffffff800655a41c 0xffffffb0cacbb3e0 : 0xffffff80065683fc 0xffffffb0cacbb440 : 0xffffff800655ab6e 0xffffffb0cacbb4e0 : 0xffffff800655df0e 0xffffffb0cacbb790 : 0xffffff800655b073 0xffffffb0cacbb8f0 : 0xffffff8006550377 0xffffffb0cacbb950 : 0xffffff8006554e88 0xffffffb0cacbbb10 : 0xffffff8003c8536e 0xffffffb0cacbbb60 : 0xffffff80037488af 0xffffffb0cacbbc70 : 0xffffff800373d95d 0xffffffb0cacbbf40 : 0xffffff8003b3fc9e 0xffffffb0cacbbfa0 : 0xffffff80034331f6 Kernel Extensions in backtrace: com.apple.security.sandbox(300.0)[C7CC6439-6854-33FB-9E97-F468B75AD280]@0xffffff8006549000->0xffffff800658efff dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff8004ac0000->0xffffff8004ad5fff dependency: com.apple.iokit.IOStorageFamily(2.1)[A0D72FE9-649B-316A-8B5C-934E295FF0B5]@0xffffff800606d000->0xffffff800607efff dependency: com.apple.kext.AppleMatch(1.0.0d1)[759DEBDE-C844-3703-A01C-4DF5EEA8F4ED]@0xffffff8004abc000->0xffffff8004abefff

Process name corresponding to current thread: NotificationCenter Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version: 20F71

Kernel version: Darwin Kernel Version 20.5.0: Sat May 8 05:10:33 PDT 2021; root:xnu-7195.121.3~9/RELEASE_X86_64 Kernel UUID: 52A1E876-863E-38E3-AC80-09BBAB13B752 KernelCache slide: 0x0000000003200000 KernelCache base: 0xffffff8003400000 Kernel slide: 0x0000000003210000 Kernel text base: 0xffffff8003410000 __HIB text base: 0xffffff8003300000 System model name: MacBookPro16,1 (Mac-E1008331FDC96864) System shutdown begun: NO Hibernation exit count: 0

All my problems started with the update to 11.4, before that I was using 11.2 and had no problems. The error is happening when I connect a second usb-c dock to HDMI to be able to use two external HDMI monitors, as soon I connect the second dongle, is go straight to the kernel error.

Frustrating indeed.

I contacted Apple Support and was escalated to a senior Mac advisor. I showed him this thread, and his immediate response was that because it is not reproduced with the Apple Multiport Adapter, it is a third-party issue.

I insisted, and explained thoroughly, that this is an issue that was introduced by an Apple update, is caused by Apple's GPU drivers, and it's unacceptable that the solution to a botched update is that I buy a 3-port $69.99 adapter.

I was told that they don't control third parties, "things change", and they don't control their drivers.

Frankly, Apple has a responsibility to make sure they don't introduce updates that make previously functional accessories crash our computers. I was told that unless I can present a convincing argument, the case will be closed because it is only affecting third-party adapters.

I explained that if the case is closed I will dedicate however long is needed to reverse-engineer the drivers and diagnose the issue, and come back with a solid case. They then promptly collected diagnostics and had me reproduce the crash three times (which happened one after another), and escalated the case to engineers out of generosity.

While this has been escalated to engineers, I don't have high hopes that this will be fixed for us. If the sentiment that was shown to me is shared by the rest of Apple, the solution is going to be that we need to buy their multiport adapter and accept it. Completely unprofessional, and certainly not a way to keep me on as a customer.

Alas Apple Support is not able to help me any further. The only fix they can provide is connecting via HDMI and not via usb-c -> DisplayPort (so far I've not been able to crash my system once it's connected via HDMI).

The Senior Advisers are not able to get through to Engineering, the feedback stays: it's a problem with the 3rd party hardware, not our system. If only this happened to a famous streamer. The HDMI solution sucks, since it means I'll only have 1 usb-c port free. But it's better than crashes.

Updating to Monterey BETA 2 fixed the issue for me as well :)

I'm on BigSur 11.4 with the same issue as describe: plug-in USB-C Dell monitor results mostly in system crashes, 1m - 2h later during web conferences / work. Same crash reports as posted here many times.

% sw_vers
ProductName:	macOS
ProductVersion:	11.4
BuildVersion:	20F71

Updating to Monterey BETA 2 fixed the issue for me as well :)

Can somebody explain how to get this beta?

Big Sur 11.5 Beta 5 is out... anyone?

Just realised one of my Dell monitors has an option to use DisplayPort 1.1 (instead of the default 1.2) and in this mode it doesn't seem to crash my laptop. I'll leave this running for another while to see if it gets around the problem.

Of course this option might not be available in more recent monitors and also DP 1.1 is very limiting in terms of resolution/refresh rate (it can't run 4K at 60fps) but for anyone with lower res monitors suffering daily crashes this might be a better compromise until Apple get their act together.

Finally! macOS Monterey 12.0 beta fixes the issue for me.

MacBook Pro 16 2019, connected to a Kapok USB-C PD Hub (https://www.amazon.ca/Adapter-Docking-Station-Monitors-Windows/dp/B08QVPY28N/ref=sr_1_6) connected to a 65W power adapter and a 4K HDMI 1.4 monitor.

With previous OS versions (tried 11.4 and 11.5 beta 5) I could easily reproduce the crash. With 12.0 beta I ran about 5 minutes of plug-unplug at 10-15 seconds of interval and my system is still up and running, stable.

Good luck to the rest of you!

Has anyone tried the 11.5 release candidate... I'm not holding my breath...

I have the same issue with my iMac 2021.

After I shut down my mac, it restarted and I got a Problem Report for MacOS prompt saying it was a Kernel version: Darwin Kernel Version 20.4.0. I searched the issue right away in Google and found out about this thread. True enough, I'm using my Baseus USB-C Dock for the first time. Hope they'll fix it soon.

Same here. Calldigit dock with 2 mons. Sometimes, it's also enough to only connect the monitor (HDMI) to the dock.

It's quite frustrating, to reboot the laptop on every dock connecting..

Same issue with MacBook Pro (16-inch, 2019) and HP Z27k G3 by connect & disconnect the monitor.

System: MacBook Pro (16-inch, 2019)

OS Version: Big Sur 11.4 (20F71)

Graphics: AMD Radeon Pro 5500M 4 GB, Intel UHD Graphics 630 1536 MB

I had encountered the same problem. Unplug and Plug USB-C cable to MacBook and Kernal panic 'element modified after free'. I'm following this thread from quite sometime now just to find any fix/workaround.

Home setup: dual monitors - DELL P2421DC directly connecting via USB-C cable (cable is from Dell, out of box with new monitors).

Office setup: dual monitors - DELL U3821DW directly connecting via USB3.1 Type C cable (80C 30V - is printed on wire) -> https://www.bizlinktech.com/products/detail/1240/USB+3.1+Gen+2+Type-C+Active+Cable

And surprisingly when I connected my MBP to external monitors in office last week, no crashes. I tested my home setup with Bizlink USB3.1 Type C cable and didn't encountered any crashes so far. I'm not sure how these cables differ. I couldn't find anything written on Dell USB-C cable to figure out.