I'm getting the same problem. Macbook Pro 16 (2019). Seemed to start occurring after a recent Big Sur update: panic(cpu 9 caller 0xffffff800669f6b6): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff937da7c800, prot:zero) 1672: 0xfffffffe00000000 Backtrace (CPU 9), Frame : Return Address 0xffffffa132adaa80 : 0xffffff8005e8e02d 0xffffffa132adaad0 : 0xffffff8005fd48e3 0xffffffa132adab10 : 0xffffff8005fc4eda 0xffffffa132adab60 : 0xffffff8005e32a2f 0xffffffa132adab80 : 0xffffff8005e8d84d 0xffffffa132adaca0 : 0xffffff8005e8db43 0xffffffa132adad10 : 0xffffff800669d68a 0xffffffa132adad80 : 0xffffff800669f6b6 0xffffffa132adb200 : 0xffffff8005eec816 0xffffffa132adb270 : 0xffffff8005e9d60c 0xffffffa132adb2c0 : 0xffffff80065af582 0xffffffa132adb2e0 : 0xffffff8008f4d73c 0xffffffa132adb300 : 0xffffff8008f5b71c 0xffffffa132adb360 : 0xffffff8008f4de8e 0xffffffa132adb400 : 0xffffff8008f50007 0xffffffa132adb6b0 : 0xffffff8008f4e393 0xffffffa132adb810 : 0xffffff8008f479e5 0xffffffa132adba10 : 0xffffff8006682f9a 0xffffffa132adba50 : 0xffffff80060f19dc 0xffffffa132adbc20 : 0xffffff80060f41a9 0xffffffa132adbd20 : 0xffffff80060f70e0 0xffffffa132adbf40 : 0xffffff8006540dae 0xffffffa132adbfa0 : 0xffffff8005e331f6 Kernel Extensions in backtrace: com.apple.security.sandbox(300.0)[A8EB8B72-CF6C-313B-96B9-B5BDA3C48E03]@0xffffff8008f3c000-0xffffff8008f81fff dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[9B4B41D7-B68F-33D5-80A4-2C4C4A649F6D]@0xffffff80074b8000-0xffffff80074cdfff dependency: com.apple.iokit.IOStorageFamily(2.1)[58EA4506-4E6B-3AC3-A70D-ED35EE2C381D]@0xffffff8008a62000-0xffffff8008a73fff dependency: com.apple.kext.AppleMatch(1.0.0d1)[47674A56-91B7-3A68-835F-A96648461333]@0xffffff80074b4000-0xffffff80074b6fff Process name corresponding to current thread: mds Boot args: chunklist-security-epoch=0 -chunklist-no-rev2-dev chunklist-security-epoch=0 -chunklist-no-rev2-dev Mac OS version: 20E241 Kernel version: Darwin Kernel Version 20.4.0: Thu Apr 22 21:46:47 PDT 2021; root:xnu-7195.101.2~1/RELEASE_X86_64 Kernel UUID: 068F99A3-1DB3-31C0-87D5-09942F122BB6 KernelCache slide: 0x0000000005c00000 KernelCache base: 0xffffff8005e00000 Kernel slide: 0x0000000005c10000 Kernel text base: 0xffffff8005e10000 __HIB text base: 0xffffff8005d00000 System model name: MacBookPro16,1 (Mac-E1008331FDC96864) System shutdown begun: NO Hibernation exit count: 44 System uptime in nanoseconds: 161940436870002 Last Sleep: absolute base_tsc base_nano Uptime : 0x00009348b236ebe4 Sleep : 0x00006922e12f9603 0x00009f11c7dab7ea 0x00006916f2c4258e Wake : 0x0000692313e0179e 0x00009f49a8fbd090 0x00006922f30d5d5e last started kext at 97018319064226: AudioAUUC 1.70 (addr 0xffffff7f9f18c000, size 12288) last stopped kext at 94784630241352: !UAudio 405.39 (addr 0xffffff7f9f112000, size 315392) loaded kexts: com.box.filesystems.osxfuse 403.11.2 AudioAUUC 1.70 @filesystems.smbfs 3.5 AGPM 122 !APlatformEnabler 2.7.0d0 X86PlatformShim 1.0.0 @filesystems.autofs 3.0 @fileutil 20.036.15 !ATopCaseHIDEventDriver 4040.11 !AHIDALSService 1 @kext.AMDRadeonX6000 4.0.4 !AUpstreamUserClient 3.6.8 @kext.AMDRadeonServiceManager 4.0.4 !A!IKBLGraphics 16.0.2 !A!ICFLGraphicsFramebuffer 16.0.2 !AGraphicsDevicePolicy 6.2.9 BridgeAudioCommunication 140.4 !AAVEBridge 6.1 !AThunderboltIP 4.0.3 @AGDCPluginDisplayMetrics 6.2.9 pmtelemetry 1 |IOUserEthernet 1.0.1 usb.!UUserHCI 1 |IO!BSerialManager 8.0.4d18 @Dont_Steal_Mac_OS_X 7.0.0 !AHV 1 !ADiskImages2 1 !A!ISlowAdaptiveClocking 4.0.0 !A!IPCHPMC 2.0.1 !ABridgeAudio!C 140.4 AGDCBacklightControl 6.2.9 !AMCCSControl 1.14 !AGFXHDA 100.1.433 !AMuxControl2 6.2.9 BCMWLANFirmware4378.Hashstore 1 BCMWLANFirmware4377.Hashstore 1 BCMWLANFirmware4364.Hashstore 1 BCMWLANFirmware4355.Hashstore 1 !AFileSystemDriver 3.0.1 @filesystems.tmpfs 1 @filesystems.hfs.kext 556.100.11 @BootCache 40 @!AFSCompression.!AFSCompressionTypeZlib 1.0.0 @!AFSCompression.!AFSCompressionTypeDataless 1.0.0d1 !ABCMWLANBusInterfacePCIeMac 1 @filesystems.apfs 1677.100.114 @private.KextAudit 1.0 !ASmartBatteryManager 161.0.0 !AACPIButtons 6.1 !ASMBIOS 2.1 !AACPIEC 6.1 !AAPIC 1.7 @!ASystemPolicy 2.0.0 @nke.applicationfirewall 311 |IOKitRegistryCompatibility 1 |EndpointSecurity 1 !UAudio 405.39 @kext.triggers 1.0 !AHS!BDriver 4040.11 IO!BHIDDriver 8.0.4d18 !AActuatorDriver 4440.3 !AMultitouchDriver 4440.3 !AInputDeviceSupport 4400.35 !AHIDKeyboard 224 @kext.AMDRadeonX6100HWLibs 1.0 @kext.AMDRadeonX6000HWServices 4.0.4 X86PlatformPlugin 1.0.0 |IOAccelerator!F2 442.9 |IO!BHost!CUARTTransport 8.0.4d18 |IO!BHost!CTransport 8.0.4d18 !A!ILpssUARTv1 3.0.60 !A!ILpssUARTCommon 3.0.60 !AOnboardSerial 1.0 !AThunderboltDPOutAdapter 8.1.4 |IOAVB!F 940.4 |IOEthernetAVB!C 1.1.0 @!AGPUWrangler 6.2.9 |IOSlowAdaptiveClocking!F 1.0.0 IOPlatformPlugin!F 6.0.0d8 !ABacklightExpert 1.1.0 !ASMBus!C 1.0.18d1 |IONDRVSupport 585.1 |IOAudio!F 300.6.1 @vecLib.kext 1.2.0 @kext.AMDRadeonX6000Framebuffer 4.0.4 @kext.AMDSupport 4.0.4 !AGraphicsControl 6.2.9 @!AGraphicsDeviceControl 6.2.9 |IOGraphics!F 585.1 @plugin.IOgPTPPlugin 980.4 usb.IOUSBHostHIDDevice 1.2 usb.cdc.ncm 5.0.0 usb.cdc.ecm 5.0.0 usb.!UHub 1.2 usb.cdc 5.0.0 usb.networking 5.0.0 usb.!UHostCompositeDevice 1.2 !AThunderboltPCIDownAdapter 4.1.1 !AThunderboltDPInAdapter 8.1.4 !AThunderboltDPAdapter!F 8.1.4 !AHPM 3.4.4 !A!ILpssI2C!C 3.0.60 !A!ILpssI2C 3.0.60 !A!ILpssDmac 3.0.60 !ABSDKextStarter 3 |IOSurface 290.7 @filesystems.hfs.encodings.kext 1 !ABCMWLANCoreMac 1.0.0 |IOSerial!F 11 |IO80211!FV2 1200.12.2b1 |IOSkywalk!F 1 mDNSOffloadUserClient 1.0.1b8 IOImageLoader 1.0.0 corecapture 1.0.4 !AXsanScheme 3 usb.!UVHCIBCE 1.2 usb.!UVHCICommonBCE 1.0 usb.!UVHCI 1.2 usb.!UVHCICommon 1.0 !AEffaceableNOR 1.0 |IOBufferCopy!C 1.1.0 |IOBufferCopyEngine!F 1 |IONVMe!F 2.1.0 !AThunderboltNHI 7.2.8 |IOThunderbolt!F 9.3.2 usb.!UHostPacketFilter 1.0 |IOUSB!F 900.4.2 usb.!UXHCIPCI 1.2 usb.!UXHCI 1.2 !AEFINVRAM 2.1 !AEFIRuntime 2.1 !ASMCRTC 1.0 |IOSMBus!F 1.1 |IOHID!F 2.0.0 $!AImage4 3.0.0 |IOTimeSync!F 980.4 |IONetworking!F 3.4 DiskImages 493.0.0 |IO!B!F 8.0.4d18 |IOReport!F 47 |IO!BPacketLogger 8.0.4d18 $quarantine 4 $sandbox 300.0 @kext.!AMatch 1.0.0d1 |CoreAnalytics!F 1 !ASSE 1.0 !AKeyStore 2 !UTDM 511.101.1 |IOUSBMass!SDriver 184.101.1 |IOSCSIBlockCommandsDevice 436.100.4 |IO!S!F 2.1 |IOSCSIArchitectureModel!F 436.100.4 !AMobileFileIntegrity 1.0.5 @kext.CoreTrust 1 !AFDEKeyStore 28.30 !AEffaceable!S 1.0 !ACredentialManager 1.0 KernelRelayHost 1 |IOUSBHost!F 1.2 !UHostMergeProperties 1.2 usb.!UCommon 1.0 !ABusPower!C 1.0 !ASEPManager 1.0.1 IOSlaveProcessor 1 !AACPIPlatform 6.1 !ASMC 3.1.9 |IOPCI!F 2.9 |IOACPI!F 1.4 watchdog 1 @kec.pthread 1 @kec.corecrypto 11.1 @kec.Libm 1