Big Sur panic when connect/disconnect usb-c dock

One more here.. It is frustrating//

Stop being such a sneaky lying *** and maybe you might be able to resolve some of your sneaky USB router issues

I've been facing the same issue for months now, it's been extremely annoying. My MBP16" 2019 crashes almost every day once or twice. A $2000+ dollars laptop that can work with a monitor is completely unacceptable.

Today I was working at the office and I got a new kernel panic while reconnecting my USB-C dock:

panic(cpu 1 caller 0xfffffff00efe8d90): x86 CPU CATERR detected
Debugger message: panic
Memory ID: 0x6
OS release type: User
OS version: 19P50284g
macOS version: 20G95
Kernel version: Darwin Kernel Version 21.0.0: Sun Jun 20 18:32:24 PDT 2021; root:xnu-8011.0.0.121.4~1/RELEASE_ARM64_T8010
Kernel UUID: 46970279-CCEF-30AD-822F-1A1053068BC2
iBoot version: iBoot-7429.0.133.121.1
secure boot?: YES
x86 EFI Boot State: 0x16
x86 System State: 0x0
x86 Power State: 0x0
x86 Shutdown Cause: 0xec
x86 Previous Power Transitions: 0x10001000100
PCIeUp link state: 0x89473611
Paniclog version: 13
Kernel slide:      0x0000000006fa4000
Kernel text base:  0xfffffff00dfa8000
mach_absolute_time: 0x864ad301482
Epoch Time:        sec       usec
  Boot    : 0x61155c50 0x000b0ffb
  Sleep   : 0x611b8616 0x00045947
  Wake    : 0x611b8787 0x00089b09
  Calendar: 0x611bd3e6 0x000d5c26

CORE 0: PC=0xfffffff00e8aa138, LR=0xfffffff00e7a685c, FP=0xffffffeb0ee63ee0
CORE 1 is the one that panicked. Check the full backtrace for details.
Panicked task 0xffffffe133564648: 0 pages, 233 threads: pid 0: kernel_task
Panicked thread: 0xffffffe133861550, backtrace: 0xffffffeb03f5b6b0, tid: 392
		  lr: 0xfffffff00e776af4  fp: 0xffffffeb03f5b6f0
		  lr: 0xfffffff00e776878  fp: 0xffffffeb03f5b760
		  lr: 0xfffffff00e8a7b7c  fp: 0xffffffeb03f5b840
		  lr: 0xfffffff00edc55fc  fp: 0xffffffeb03f5b850
		  lr: 0xfffffff00e77658c  fp: 0xffffffeb03f5bbd0
		  lr: 0xfffffff00e77658c  fp: 0xffffffeb03f5bc30
		  lr: 0xfffffff00f89b440  fp: 0xffffffeb03f5bc50
		  lr: 0xfffffff00efe8d90  fp: 0xffffffeb03f5bc80
		  lr: 0xfffffff00efd636c  fp: 0xffffffeb03f5bce0
		  lr: 0xfffffff00efdc800  fp: 0xffffffeb03f5bd30
		  lr: 0xfffffff00efd8258  fp: 0xffffffeb03f5bdd0
		  lr: 0xfffffff00efd5a50  fp: 0xffffffeb03f5be50
		  lr: 0xfffffff00ee9e7c4  fp: 0xffffffeb03f5be80
		  lr: 0xfffffff00ed128e4  fp: 0xffffffeb03f5bec0
		  lr: 0xfffffff00ed120f0  fp: 0xffffffeb03f5bf00
		  lr: 0xfffffff00edd05c0  fp: 0x0000000000000000

This sounds more serious though :(

Same issue with my 13' MBP 2020 i7 running Big Sur 11.5 and the CalDigit USB-C dock (Thunderbolt 3 mini Dock):

panic(cpu 4 caller 0xffffff80196e28c3): "waitq deadlock - waitq=0xffffff86c75a6c90, cpu=4\n"@/System/Volumes/Data/SWE/macOS/BuildRoots/d7e177bcf5/Library/Caches/com.apple.xbs/Sources/xnu/xnu-7195.141.2/osfmk/kern/waitq.c:2005
Backtrace (CPU 4), Frame : Return Address
0xffffffa12108bb00 : 0xffffff801968e04d
0xffffffa12108bb50 : 0xffffff80197d4e13
0xffffffa12108bb90 : 0xffffff80197c540a
0xffffffa12108bbe0 : 0xffffff8019632a2f
0xffffffa12108bc00 : 0xffffff801968d86d
0xffffffa12108bd20 : 0xffffff801968db63
0xffffffa12108bd90 : 0xffffff8019e9dc0a
0xffffffa12108be00 : 0xffffff80196e28c3
0xffffffa12108be20 : 0xffffff801966f29c
0xffffffa12108be60 : 0xffffff80196813ae
0xffffffa12108bef0 : 0xffffff80197a970d
0xffffffa12108bfa0 : 0xffffff8019633216

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

Mac OS version:
20G71

Kernel version:
Darwin Kernel Version 20.6.0: Wed Jun 23 00:26:31 PDT 2021; root:xnu-7195.141.2~5/RELEASE_X86_64
Kernel UUID: FECBF22B-FBBE-36DE-9664-F12A7DD41D3D
KernelCache slide: 0x0000000019400000
KernelCache base:  0xffffff8019600000
Kernel slide:      0x0000000019410000
Kernel text base:  0xffffff8019610000
__HIB  text base: 0xffffff8019500000
System model name: MacBookPro16,2 (Mac-5F9802EFE386AA28)
System shutdown begun: NO
Hibernation exit count: 3

Anyone would have any idea to solve this?

Experiencing the same issue daily for months with my 2019 i9 MBP 16" + Dell U2719H connected via display port. Annoying. Nothing solved the problem to me yet.

panic(cpu 6 caller 0xffffff8017e9fc36): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff939025d000, prot:zero)
 1672: 0xfffffffe00000000

Just to Chime in:

• Brand spanking new 16" Macbook,
• Big Sur 11.5.1
• Lenovo dock ldc-g2 connected over USB-C, monitor on DisplayPort
• Multiple hard crashes a day with this same kernel panic error, mostly when removing or reconnecting the dock, maybe 5-10s after it.

I am going to swap this out for an HDMI cable this weekend and report back on results.

Same issue here. Consistent crash when I connect to the dock.

MacBook Pro (16-inch, 2019) + Belkin Thunderbolt 3 Pro Dock + Dell U3818DW

Same problem here since the Big Sur Update. I submitted every panic to Apple.

I attached the last one...

Same here since i got my 16" MacBook Pro (2019) AMD Radeon 5300M 18 Month ago. Happens every time i plug/unplug my usb-c docking station (HP G5). MacOS Big Sur 11.5.2.

panic(cpu 4 caller 0xffffff8005e9fc36): [kext.kalloc.2048]: element modified after free (off:1584, val:0x0000210100000000, sz:2048, ptr:0xffffff9366301000, prot:zero)
 1584: 0x0000210100000000
 1592: 0x0000000b00005400
 1600: 0x0000000000000009
 1608: 0x0000020300000100
 1616: 0x0000015400000154
 1624: 0x0000000100000a00
 1632: 0x000008340000041a
 1640: 0x0000000000001400
 1672: 0xfffffffe00000000
Backtrace (CPU 4), Frame : Return Address
0xffffffb0cec0a570 : 0xffffff800568e04d 
0xffffffb0cec0a5c0 : 0xffffff80057d4e13 
0xffffffb0cec0a600 : 0xffffff80057c540a 
0xffffffb0cec0a650 : 0xffffff8005632a2f 

I have been encountering this issue for like 3 months already. It's good to see a dedicated thread for this but too bad it's still an issue and we're already in page 7. I am using my 2019 Macbook Pro 16" at Big Sur 11.5

panic(cpu 2 caller 0xffffff801749a9b6): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff9373558000, prot:zero)
1672: 0xfffffffe00000000
Backtrace (CPU 2), Frame : Return Address
0xffffffb0e5f4a550 : 0xffffff8016c8915d 
0xffffffb0e5f4a5a0 : 0xffffff8016dd0033 
0xffffffb0e5f4a5e0 : 0xffffff8016dc062a 
0xffffffb0e5f4a630 : 0xffffff8016c2da2f 
0xffffffb0e5f4a650 : 0xffffff8016c8897d 
0xffffffb0e5f4a770 : 0xffffff8016c88c73 
0xffffffb0e5f4a7e0 : 0xffffff801749898a 
0xffffffb0e5f4a850 : 0xffffff801749a9b6 
0xffffffb0e5f4acd0 : 0xffffff8016ce7b56 
0xffffffb0e5f4ad40 : 0xffffff8016c9873c 
0xffffffb0e5f4ad90 : 0xffffff80173a95f2 
0xffffffb0e5f4adb0 : 0xffffff8019d5a41c 
0xffffffb0e5f4add0 : 0xffffff8019d683fc 
0xffffffb0e5f4ae30 : 0xffffff8019d5ab6e 
0xffffffb0e5f4aed0 : 0xffffff8019d5cce7 
0xffffffb0e5f4b180 : 0xffffff8019d60b7d 
0xffffffb0e5f4b450 : 0xffffff8019d7023f 
0xffffffb0e5f4b640 : 0xffffff8019d560b4 
0xffffffb0e5f4b9e0 : 0xffffff8019d56abf 
0xffffffb0e5f4ba40 : 0xffffff801747c4a6 
0xffffffb0e5f4ba80 : 0xffffff8016f5144e 
0xffffffb0e5f4bd50 : 0xffffff8016f32e43 
0xffffffb0e5f4bf40 : 0xffffff801733ad9e 
0xffffffb0e5f4bfa0 : 0xffffff8016c2e1f6 
      Kernel Extensions in backtrace:
         com.apple.security.sandbox(300.0)[1D016FA0-09CF-3D63-A613-57B7A8AA640C]@0xffffff8019d49000->0xffffff8019d8efff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[F5BC1EC5-40C5-36E6-8F25-BA1DFE57654A]@0xffffff80182c0000->0xffffff80182d5fff
            dependency: com.apple.iokit.IOStorageFamily(2.1)[3DE94082-367D-3255-9BE7-7F5A87838247]@0xffffff801986e000->0xffffff801987ffff
            dependency: com.apple.kext.AppleMatch(1.0.0d1)[87BEAD84-D39B-36F5-9703-26D5D48C188D]@0xffffff80182bc000->0xffffff80182befff

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

Mac OS version:
20G5023d

Kernel version:
Darwin Kernel Version 20.6.0: Mon May 10 03:15:35 PDT 2021; root:xnu-7195.140.13.0.1~20/RELEASE_X86_64
Kernel UUID: 3893CD5D-E480-3097-A4F4-3F1A6D146AE4
KernelCache slide: 0x0000000016a00000
KernelCache base:  0xffffff8016c00000
Kernel slide:      0x0000000016a10000
Kernel text base:  0xffffff8016c10000
__HIB  text base: 0xffffff8016b00000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 11

Been having this issue at work for about 3 months now. It had gotten worse and worse. Every update that comes out i install instantly but it only makes the crashed happen more frequent. I'm really regetting updating to Big Sur.

The following crash will happen about 2 times a day. It's always when i connect one of my external monitors usb-c to display.

panic(cpu 10 caller 0xffffff801b69fc36): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff93787f5800, prot:zero)
 1672: 0xfffffffe00000000
Backtrace (CPU 10), Frame : Return Address
0xffffffb0e4842cf0 : 0xffffff801ae8e04d 
0xffffffb0e4842d40 : 0xffffff801afd4e13 
0xffffffb0e4842d80 : 0xffffff801afc540a 
0xffffffb0e4842dd0 : 0xffffff801ae32a2f 
0xffffffb0e4842df0 : 0xffffff801ae8d86d 
0xffffffb0e4842f10 : 0xffffff801ae8db63 
0xffffffb0e4842f80 : 0xffffff801b69dc0a 
0xffffffb0e4842ff0 : 0xffffff801b69fc36 
0xffffffb0e4843470 : 0xffffff801aeec9e6 
0xffffffb0e48434e0 : 0xffffff801ae9d65c 
0xffffffb0e4843530 : 0xffffff801b5ae872 
0xffffffb0e4843550 : 0xffffff7fb52fefce 
0xffffffb0e4843600 : 0xffffff7fb52ff65e 
0xffffffb0e4843640 : 0xffffff7fb52bfc4a 
0xffffffb0e4843660 : 0xffffff7fb5bf9e78 
0xffffffb0e4843900 : 0xffffff7fb52c07e8 
0xffffffb0e4843930 : 0xffffff7fb5bfb074 
0xffffffb0e48439c0 : 0xffffff7fb5bf90f7 
0xffffffb0e4843a10 : 0xffffff7fb5bf8ee7 
0xffffffb0e4843a60 : 0xffffff7fb5bf7f99 
0xffffffb0e4843aa0 : 0xffffff801b61e4be 
0xffffffb0e4843af0 : 0xffffff7fb52c04a6 
0xffffffb0e4843b20 : 0xffffff801b62876b 
0xffffffb0e4843c80 : 0xffffff801af80841 
0xffffffb0e4843d90 : 0xffffff801ae936cd 
0xffffffb0e4843e00 : 0xffffff801ae69cf5 
0xffffffb0e4843e60 : 0xffffff801ae81252 
0xffffffb0e4843ef0 : 0xffffff801afa970d 
0xffffffb0e4843fa0 : 0xffffff801ae33216 
      Kernel Extensions in backtrace:
         com.apple.iokit.IOAcceleratorFamily2(442.9)[8F6B0D56-AFD7-38F7-8EDA-B43ACA468394]@0xffffff7fb5bb4000->0xffffff7fb5c1efff
            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[152D7047-0D43-3CA8-B1EA-251D3F80AC28]@0xffffff801c4c0000->0xffffff801c4d5fff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[B5241FDE-C525-39D6-9813-2BE73DD7CEE3]@0xffffff7fb5d35000->0xffffff7fb5d63fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[F7AA4BAF-35CF-3784-A50C-5FD9CDCBE488]@0xffffff801d96c000->0xffffff801d994fff
            dependency: com.apple.iokit.IOReportFamily(47)[AE367C5D-FEFC-390D-ABDF-86E037890F00]@0xffffff801d9a3000->0xffffff801d9a5fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[DCE8209F-A72D-3EBA-BE93-C0AF896AA9B5]@0xffffff801da96000->0xffffff801dab2fff
         com.apple.driver.AppleIntelKBLGraphics(16.0.5)[8B11EE30-3D67-3FB9-9F2E-46A1B159E059]@0xffffff7fb52a9000->0xffffff7fb5360fff
            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[8F6B0D56-AFD7-38F7-8EDA-B43ACA468394]@0xffffff7fb5bb4000->0xffffff7fb5c1efff
            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[B5241FDE-C525-39D6-9813-2BE73DD7CEE3]@0xffffff7fb5d35000->0xffffff7fb5d63fff
            dependency: com.apple.iokit.IOPCIFamily(2.9)[F7AA4BAF-35CF-3784-A50C-5FD9CDCBE488]@0xffffff801d96c000->0xffffff801d994fff
            dependency: com.apple.iokit.IOSurface(290.8.1)[DCE8209F-A72D-3EBA-BE93-C0AF896AA9B5]@0xffffff801da96000->0xffffff801dab2fff

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

Mac OS version:
20G80

Kernel version:
Darwin Kernel Version 20.6.0: Wed Jun 23 00:26:31 PDT 2021; root:xnu-7195.141.2~5/RELEASE_X86_64
Kernel UUID: FECBF22B-FBBE-36DE-9664-F12A7DD41D3D
KernelCache slide: 0x000000001ac00000
KernelCache base:  0xffffff801ae00000
Kernel slide:      0x000000001ac10000
Kernel text base:  0xffffff801ae10000
__HIB  text base: 0xffffff801ad00000
System model name: MacBookPro16,1 (Mac-E1008331FDC96864)
System shutdown begun: NO
Hibernation exit count: 1

Happens to me as well as described by @dbdotconf. I use 2 monitors with 16'' 2021 Big Sur 11.5.1. The same flow of actions, almost every day when I plug in monitors via 2 TB3, I hear fans and then it crashes and reboots. Also send report every time. This is very annoying. Such amount of money was paid not for such an experience with Mac which is supposed to be ideal.

And yes my crash starts with "[kext.kalloc.2048]: element modified after free" and cpu panic as well.

cpu...panic...[kext.kalloc.2048]: element modified after free....

2021 16'' Big Sur 11.5.1, still happens every day when I start my work in the morning and connect 2 monitors via TB3.

Jeeezzzz...