Big Sur panic when connect/disconnect usb-c dock

I'm having the same issue when connecting one of my usb-c docks (CalDigit USB-C Pro Dock and StarTech.com Thunderbolt 3 Dock). MacBook Pro (16-inch, 2019) - macOS 11.4

0xffffffa12b02bfa0 : 0xffffff80014331f6
      Kernel Extensions in backtrace:
         com.apple.security.sandbox(300.0)[C7CC6439-6854-33FB-9E97-F468B75AD280]@0xffffff8004549000->0xffffff800458efff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff8002ac0000->0xffffff8002ad5fff
            dependency: com.apple.iokit.IOStorageFamily(2.1)[A0D72FE9-649B-316A-8B5C-934E295FF0B5]@0xffffff800406d000->0xffffff800407efff
            dependency: com.apple.kext.AppleMatch(1.0.0d1)[759DEBDE-C844-3703-A01C-4DF5EEA8F4ED]@0xffffff8002abc000->0xffffff8002abefff

Process name corresponding to current thread: lghub_agent

0xffffffa12af6bfa0 : 0xffffff8015033216
      Kernel Extensions in backtrace:
         com.apple.iokit.IOAcceleratorFamily2(442.9)[5523A2B9-D179-3560-9738-E720033965D7]@0xffffff7fae51a000->0xffffff7fae584fff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[9B4B41D7-B68F-33D5-80A4-2C4C4A649F6D]@0xffffff80166b8000->0xffffff80166cdfff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[CC341A35-707F-3C8B-8EFD-925F742166A1]@0xffffff7fae69b000->0xffffff7fae6c9fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[B99B3B05-71B8-3178-8C27-E0A0ACA9F16E]@0xffffff8017b5f000->0xffffff8017b87fff
            dependency: com.apple.iokit.IOReportFamily(47)[3F7604AB-EA65-3904-A1F4-AFEB25D288A7]@0xffffff8017b96000->0xffffff8017b98fff
            dependency: com.apple.iokit.IOSurface(290.7)[6AE0FD31-9444-350A-88A6-620DF634FF78]@0xffffff8017c89000->0xffffff8017ca5fff
         com.apple.kext.AMDRadeonX6000(4.0.4)[F9A8D4D1-CA26-3CD7-B8B5-0D9C0AF929A1]@0xffffff7fa3b7d000->0xffffff7fa3cb1fff
            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[5523A2B9-D179-3560-9738-E720033965D7]@0xffffff7fae51a000->0xffffff7fae584fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[CC341A35-707F-3C8B-8EFD-925F742166A1]@0xffffff7fae69b000->0xffffff7fae6c9fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[B99B3B05-71B8-3178-8C27-E0A0ACA9F16E]@0xffffff8017b5f000->0xffffff8017b87fff
            dependency: com.apple.iokit.IOSurface(290.7)[6AE0FD31-9444-350A-88A6-620DF634FF78]@0xffffff8017c89000->0xffffff8017ca5fff

Process name corresponding to current thread: Google Chrome Helper (GPU)

0xffffffa12dd23fa0 : 0xffffff8001433216
      Kernel Extensions in backtrace:
         com.apple.iokit.IOAcceleratorFamily2(442.9)[5523A2B9-D179-3560-9738-E720033965D7]@0xffffff7f9a91a000->0xffffff7f9a984fff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[9B4B41D7-B68F-33D5-80A4-2C4C4A649F6D]@0xffffff8002ab8000->0xffffff8002acdfff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[CC341A35-707F-3C8B-8EFD-925F742166A1]@0xffffff7f9aa9b000->0xffffff7f9aac9fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[B99B3B05-71B8-3178-8C27-E0A0ACA9F16E]@0xffffff8003f5f000->0xffffff8003f87fff
            dependency: com.apple.iokit.IOReportFamily(47)[3F7604AB-EA65-3904-A1F4-AFEB25D288A7]@0xffffff8003f96000->0xffffff8003f98fff
            dependency: com.apple.iokit.IOSurface(290.7)[6AE0FD31-9444-350A-88A6-620DF634FF78]@0xffffff8004089000->0xffffff80040a5fff
         com.apple.kext.AMDRadeonX6000(4.0.4)[F9A8D4D1-CA26-3CD7-B8B5-0D9C0AF929A1]@0xffffff7f8ff7d000->0xffffff7f900b1fff
            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[5523A2B9-D179-3560-9738-E720033965D7]@0xffffff7f9a91a000->0xffffff7f9a984fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[CC341A35-707F-3C8B-8EFD-925F742166A1]@0xffffff7f9aa9b000->0xffffff7f9aac9fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[B99B3B05-71B8-3178-8C27-E0A0ACA9F16E]@0xffffff8003f5f000->0xffffff8003f87fff
            dependency: com.apple.iokit.IOSurface(290.7)[6AE0FD31-9444-350A-88A6-620DF634FF78]@0xffffff8004089000->0xffffff80040a5fff

Process name corresponding to current thread: idea

still nothing fixed with 11.5 beta 2, whether Apple simply has no more priority on it or they can just add new bugs and not fix any more because missing knowledge on this topic.

I have the same problem on my MacBook Pro (16-inch, 2019), with the CalDigit USB-C Pro Dock (which is confusingly actually Thunderbolt 3). I have a 4K screen attached to the Dock over HDMI. I get the kernel panic with "modified after free" when I plug in the dock.

I'm pretty sure the kernel panics started with the Big Sur 11.3.1 update for me. The 11.4 update didn't fix it.

My wife is using the same dock with her M1 MacBook Air and does not see the issue.

I have had this happening for months now. This is becoming a daily pain to deal with at office now given how often I have to undock my MBP and move around. I finally got frustrated enough to reset my NVRAM/erase disk/reinstall Big Sur and it happened again immediately before I even starting reinstalling software.

It was bad enough having to unplug/replug the dock to just get my second monitor active again in the past. The kernel panics have made this so much worse.

I am using a CalDigit USB-C Pro Dock at work and a CalDigit TS3 Plus Thunderbolt 3 Dock at home, both cause the issue.

 1672: 0xfffffffe00000000
Backtrace (CPU 3), Frame : Return Address
0xffffffb0e409ac10 : 0xffffff801c48e0dd 
0xffffffb0e409ac60 : 0xffffff801c5d4f33 
0xffffffb0e409aca0 : 0xffffff801c5c552a 
0xffffffb0e409acf0 : 0xffffff801c432a2f 
0xffffffb0e409ad10 : 0xffffff801c48d8fd 
0xffffffb0e409ae30 : 0xffffff801c48dbf3 
0xffffffb0e409aea0 : 0xffffff801cc9d81a 
0xffffffb0e409af10 : 0xffffff801cc9f846 
0xffffffb0e409b390 : 0xffffff801c4ecad6 
0xffffffb0e409b400 : 0xffffff801c49d6bc 
0xffffffb0e409b450 : 0xffffff801cbae4f2 
0xffffffb0e409b470 : 0xffffff801f55a41c 
0xffffffb0e409b490 : 0xffffff801f5683fc 
0xffffffb0e409b4f0 : 0xffffff801f55ab6e 
0xffffffb0e409b590 : 0xffffff801f55cce7 
0xffffffb0e409b840 : 0xffffff801f55b073 
0xffffffb0e409b9a0 : 0xffffff801f56b882 
0xffffffb0e409bbb0 : 0xffffff801f56b564 
0xffffffb0e409bed0 : 0xffffff801cc79f5e 
0xffffffb0e409bf40 : 0xffffff801cb3fc9e 
0xffffffb0e409bfa0 : 0xffffff801c4331f6 
      Kernel Extensions in backtrace:
         com.apple.security.sandbox(300.0)[C7CC6439-6854-33FB-9E97-F468B75AD280]@0xffffff801f549000->0xffffff801f58efff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff801dac0000->0xffffff801dad5fff
            dependency: com.apple.iokit.IOStorageFamily(2.1)[A0D72FE9-649B-316A-8B5C-934E295FF0B5]@0xffffff801f06d000->0xffffff801f07efff
            dependency: com.apple.kext.AppleMatch(1.0.0d1)[759DEBDE-C844-3703-A01C-4DF5EEA8F4ED]@0xffffff801dabc000->0xffffff801dabefff

Process name corresponding to current thread: mds
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: 0x000000001c200000
KernelCache base:  0xffffff801c400000
Kernel slide:      0x000000001c210000
Kernel text base:  0xffffff801c410000
__HIB  text base: 0xffffff801c300000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 0

System uptime in nanoseconds: 5557308287228
Last Sleep:           absolute           base_tsc          base_nano
  Uptime  : 0x0000050de962eb77
  Sleep   : 0x00000360d7e59ac6 0x0000819188b511fa 0x0000035e0cc98a3f
  Wake    : 0x000003610ac134ae 0x000081dd606e7b8c 0x00000360e9e6e12e
last started kext at 5485587191614: >usb.cdc.acm	5.0.0 (addr 0xffffff7fb6fa2000, size 8192)
last stopped kext at 4030580153044: >usb.serial	6.0.0 (addr 0xffffff7fb700c000, size 20480)

I'm also seeing constant kernel panics when connecting/disconnecting my monitors. I have a 2021 16" MacBook Pro (2019 model, 2.3 GHz 8-Core Intel Core i9, 32 GB 2667 MHz DDR4, Intel UHD Graphics 630 1536 M😎 and am running Big Sur 11.3.1. The machine is only a couple of weeks old and I can easily reproduce the problem by simply connecting and disconnecting the monitor cable 2 or 3 times.

I initially thought the problem was my CalDigit TS3 Plus but I started to remove all peripherals to see what was causing the problem and eventually got to a single monitor (Dell U2415) and a single USB-C to DisplayPort cable - no dock or hub involved. I disconnected keyboard, trackpad, headphones, yubi key, etc etc. I even booted in safe mode but issue persists.

My crash report is the same as reported by most folks in this thread: panic(cpu 0 caller 0xffffff801d69f6b6): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff93926d4000, prot:zero)

The interesting bit I found was that everything works fine if I connect my monitors via HDMI rather than DisplayPort. So at the moment I have 2 external monitor connected via USB-C to HDMI cables (1 using the TS3 dock, and 1 using a cheap USB hub).

Reproduced in macOS 12 Monterey 🤦‍♂️

Every day this machine crashes, a top of the line 16" MBP. Now in Monterey?? 

Mine still crashes aswell, everyday after waking up, high fan, dead. restart with Errors.

I called Belkin Support, they told me they are aware of that Problem and it only appears on Big Sur. They can't do anything as the Device has no Firmware. It's totally up to Apple.

Same issue here for months, same two monitors or mostly after other monitors connected, eg TV in mtg room. Sometime just turning monitors on/off or unplugging/plugin the cable again. Also in 11.4 😦

Belkin has official Announcement about Macbook Pros 2019 - 2020: https://www.belkin.com/de/support-article?articleNum=318353

I have had the same problem on Big Sur using a Dell WD19TB Thunderbolt Docking Station.

 1584: 0x0000210100000000
 1592: 0x0000000b00005400
 1600: 0x0000000000000009
 1608: 0x0000020300000100
 1616: 0x0000015400000154
 1624: 0x0000000100000a00
 1632: 0x000008340000041a
 1640: 0x0000000000001400
Backtrace (CPU 10), Frame : Return Address
0xffffffa0d3562cf0 : 0xffffff8009a8e0dd 
0xffffffa0d3562d40 : 0xffffff8009bd4f33 
0xffffffa0d3562d80 : 0xffffff8009bc552a 
0xffffffa0d3562dd0 : 0xffffff8009a32a2f 
0xffffffa0d3562df0 : 0xffffff8009a8d8fd 
0xffffffa0d3562f10 : 0xffffff8009a8dbf3 
0xffffffa0d3562f80 : 0xffffff800a29d81a 
0xffffffa0d3562ff0 : 0xffffff800a29f846 
0xffffffa0d3563470 : 0xffffff8009aecad6 
0xffffffa0d35634e0 : 0xffffff8009a9d6bc 
0xffffffa0d3563530 : 0xffffff800a1ae4f2 
0xffffffa0d3563550 : 0xffffff7fa3ef8fce 
0xffffffa0d3563600 : 0xffffff7fa3ef965e 
0xffffffa0d3563640 : 0xffffff7fa3eb9d86 
0xffffffa0d3563660 : 0xffffff7fa47f3e78 
0xffffffa0d3563900 : 0xffffff7fa3eba924 
0xffffffa0d3563930 : 0xffffff7fa47f5074 
0xffffffa0d35639c0 : 0xffffff7fa47f30f7 
0xffffffa0d3563a10 : 0xffffff7fa47f2ee7 
0xffffffa0d3563a60 : 0xffffff7fa47f1f99 
0xffffffa0d3563aa0 : 0xffffff800a21e13e 
0xffffffa0d3563af0 : 0xffffff7fa3eba5e2 
0xffffffa0d3563b20 : 0xffffff800a22837b 
0xffffffa0d3563c80 : 0xffffff8009b80961 
0xffffffa0d3563d90 : 0xffffff8009a9375d 
0xffffffa0d3563e00 : 0xffffff8009a69cf5 
0xffffffa0d3563e60 : 0xffffff8009a81312 
0xffffffa0d3563ef0 : 0xffffff8009ba982d 
0xffffffa0d3563fa0 : 0xffffff8009a33216 
      Kernel Extensions in backtrace:
         com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7fa47ae000->0xffffff7fa4818fff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[366C7BD4-9502-3D1C-ABBE-DE9749913D0C]@0xffffff800b0c0000->0xffffff800b0d5fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7fa492f000->0xffffff7fa495dfff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff800c56a000->0xffffff800c592fff
            dependency: com.apple.iokit.IOReportFamily(47)[367CCAE7-DAB4-3424-B191-44044619D5CB]@0xffffff800c5a1000->0xffffff800c5a3fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff800c694000->0xffffff800c6b0fff
         com.apple.driver.AppleIntelKBLGraphics(16.0.4)[F7BCF586-AF08-3277-9C66-04F439E684B4]@0xffffff7fa3ea3000->0xffffff7fa3f5afff
            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[BDA1401D-563F-3650-B616-C8073E90475B]@0xffffff7fa47ae000->0xffffff7fa4818fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[2C81B74F-C771-3643-82EC-12CD4AC5EFDB]@0xffffff7fa492f000->0xffffff7fa495dfff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[99A70889-A31C-3B25-8E88-ADD3F317E4E4]@0xffffff800c56a000->0xffffff800c592fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[8FA218E4-361C-3C8B-94F0-48434AA535A0]@0xffffff800c694000->0xffffff800c6b0fff

Process name corresponding to current thread: TouchBarServer
Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev 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: 0x0000000009800000
KernelCache base:  0xffffff8009a00000
Kernel slide:      0x0000000009810000
Kernel text base:  0xffffff8009a10000
__HIB  text base: 0xffffff8009900000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 12

System uptime in nanoseconds: 44120622946291
Last Sleep:           absolute           base_tsc          base_nano
  Uptime  : 0x00002820a20edafc
  Sleep   : 0x0000281a9b5f8e9a 0x0000000201beb7d4 0x0000280af830fca7
  Wake    : 0x0000281abf2d9789 0x0000000200a50fbc 0x0000281aaa3beba3
last started kext at 14175647796: >AGPM	122.1 (addr 0xffffff7fa31a3000, size 118784)
loaded kexts:

Dear Apple Support & Engineers

The is simply unacceptable. I get 2 crashes per day!!!

I first reported this 2 months ago, after the first crash, right after the update to Big Sur 11.3 Then updated to 11.4 hoping it would fix it? Of course, it didn't.

The issue is with osX. I tried 5 different docks, my CalDigit and 4 that I borrowed from colleagues at the office (CalDigit, HP, StartTech, some no-name from Amazon & Microsoft one), all having the same problem with I connect my MacBook Pro 16 (it's less than 9 month old!!) - it crashes within 10 seconds of connecting to dock. I have to reboot it.

The crash report is different every time too? See attached samples from the past few weeks

RIDICULOUS!!

1. crash_report_202106220852.txt
2. crash_report_202106161018.txt
3. crash_report_202106160010.txt
4. crash_report_202005101310.txt
5. crash_report_202005061010.txt

This is getting ridiculous, I keep getting interrupted in my work because of this. Apple what are you doing ? You still have to support the intel based hardware !!

@apple can you please take this seriously.

This has been going for months - many threads in apple developer, reddit, news articles, etc but still no fix. I'm on big sur 11.4, this problem always happens when connecting to dock.

Submitted to APPLE so many times.

Details:

MacBook Pro (16-inch, 2019) 2.6 GHz 6-Core Intel Core i7 AMD Radeon Pro 5300M 4 GB Intel UHD Graphics 630 1536 MB

panic(cpu 4 caller 0xffffff8013a9f846): [kext.kalloc.2048]: element modified after free (off:1672, val:0xffffffff00000000, sz:2048, ptr:0xffffff9372beb000, prot:zero) 1672: 0xffffffff00000000 Backtrace (CPU 4), Frame : Return Address 0xffffffa0c6882c10 : 0xffffff801328e0dd .... Kernel Extensions in backtrace: com.apple.kext.AMDRadeonX6000Framebuffer(4.0.5)[57D9B457-0E07-3304-B3E5-2D05A3E6FB13]@0xffffff7fa1ef6000->0xffffff7fa2170fff dependency: com.apple.AppleGraphicsDeviceControl(6.3.3)[6E0CE02A-0480-3500-9A25-9CD277522DF9]@0xffffff7fac94a000->0xffffff7fac94dfff dependency: com.apple.iokit.IOACPIFamily(1.4) .... Process name corresponding to current thread: kernel_task Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev 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

Hi all, found this thread by googling the first line of my crash report.

I am getting the exact same issue (16", 11.4) only I am using the Pluggable TBT3-UDZ TB3 dock.

The issue seemed to be related often to one of my external monitors turning on/off or the cables being plugged in or out. I'd get the fan whir and a crash out to restart. It sometime happened when the dock itself was plugged in or out (which would of course include the monitors disconnecting). The only time it happened when I left the dock connected was when the monitors were doing something.

Switching to the HDMI ports on the dock from DP (this dock offers the choice of DP or HDMI for both of it's outputs thankfully) seems to have fixed the issue. My guess is that it is related to the signal that Display port sends back to the computer (called EDID?) to tell it whether the monitor is switched on or not. On DP, if I turned a monitor off it would blank out the other displays for a moment and rejig the arrangement in settings. With HDMI, turning the monitor off doesn't do this and the monitor is still listed in settings.

Hopefully that helps someone else out until apple pull their socks up!

Richard.