Macbook Pro 16" crashes randomly when connected to monitor

This seems to only happen when I'm connected directly to a monitor. Does not happen when connected with my docks, only when connected directly via USB-C to display port.

It is more likely to happen when waking from sleep after walking away for a few minutes. Or when disconnecting and reconnecting the monitor because it does not detect it.

Now it happened for the first time in the middle of writing an email.

This is the report:

panic(cpu 3 caller 0xffffff801729fc36): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff938f917000, prot:zero)

 1672: 0xfffffffe00000000

Backtrace (CPU 3), Frame : Return Address

0xffffffc140f3bfa0 : 0xffffff8016a33216 

      Kernel Extensions in backtrace:

         com.apple.iokit.IOAcceleratorFamily2(442.9)[8F6B0D56-AFD7-38F7-8EDA-B43ACA468394]@0xffffff7fb17b4000->0xffffff7fb181efff

            dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[152D7047-0D43-3CA8-B1EA-251D3F80AC28]@0xffffff80180c0000->0xffffff80180d5fff

            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[B5241FDE-C525-39D6-9813-2BE73DD7CEE3]@0xffffff7fb1935000->0xffffff7fb1963fff

            dependency: com.apple.iokit.IOPCIFamily(2.9)[F7AA4BAF-35CF-3784-A50C-5FD9CDCBE488]@0xffffff801956c000->0xffffff8019594fff

            dependency: com.apple.iokit.IOReportFamily(47)[AE367C5D-FEFC-390D-ABDF-86E037890F00]@0xffffff80195a3000->0xffffff80195a5fff

            dependency: com.apple.iokit.IOSurface(290.8.1)[DCE8209F-A72D-3EBA-BE93-C0AF896AA9B5]@0xffffff8019696000->0xffffff80196b2fff

         com.apple.driver.AppleIntelKBLGraphics(16.0.5)[8B11EE30-3D67-3FB9-9F2E-46A1B159E059]@0xffffff7fb0ea9000->0xffffff7fb0f60fff

            dependency: com.apple.iokit.IOAcceleratorFamily2(442.9)[8F6B0D56-AFD7-38F7-8EDA-B43ACA468394]@0xffffff7fb17b4000->0xffffff7fb181efff

            dependency: com.apple.iokit.IOGraphicsFamily(585.1)[B5241FDE-C525-39D6-9813-2BE73DD7CEE3]@0xffffff7fb1935000->0xffffff7fb1963fff

            dependency: com.apple.iokit.IOPCIFamily(2.9)[F7AA4BAF-35CF-3784-A50C-5FD9CDCBE488]@0xffffff801956c000->0xffffff8019594fff

            dependency: com.apple.iokit.IOSurface(290.8.1)[DCE8209F-A72D-3EBA-BE93-C0AF896AA9B5]@0xffffff8019696000->0xffffff80196b2fff

Process name corresponding to current thread: TouchBarServer

Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev

Mac OS version:

20G95

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: 0x0000000016800000

KernelCache base:  0xffffff8016a00000

Kernel slide:      0x0000000016810000

Kernel text base:  0xffffff8016a10000

__HIB  text base: 0xffffff8016900000

System model name: MacBookPro16,1 (Mac-E1008331FDC96864)

System shutdown begun: NO

Hibernation exit count: 4

I had to trim down the report to fit in the post

Experiencing the same issues with 2 MBP 16's with the same extensions in the backtrace. Connecting via usbc to a single LG monitor.

Hi, could you both file this on Feedback Assistant? I couldn't find any similar reports. Please include the crash reports, sysdiagnoses, and monitor types you used.

This looks similar to a long standing issue: https://developer.apple.com/forums/thread/678644

In my case, switching to a HDMI cable resolved the issue. Depending on your monitor, you could also try to switch to DisplayPort 1.1 if it supports.

Macbook Pro 16" crashes randomly when connected to monitor
 
 
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