A7500 recurring BSOD when used as Hyper-V virtual switch — WinDbg points to mtkwl6eux.sys

Experiencing recurring BSODs with my A7500 when configured as a Hyper-V external virtual switch on Windows 11 24H2. 4 crashes in 6 days. The adapter works fine in normal (non-Hyper-V)

usage.

Reproduction (on my system):

1. Enable Hyper-V on Windows 11 24H2

2. Create an external virtual switch bound to the A7500 shared with mgmt OS

3. Connect to a WiFi network

4. System BSODs within hours to days

WinDbg analysis of the full kernel memory dump points to mtkwl6eux.sys (though I'm not a kernel debugging expert, so corrections welcome):

- Bugcheck 0x139 (KERNEL_SECURITY_CHECK_FAILURE), param 0x3 — LIST_ENTRY corruption

- A system thread created by mtkwl6eux.sys waits on an I/O buffer (pool tag IoSB) in nonpaged pool

- The wait block for this thread is corrupted — both list pointers zeroed, Thread field NULL — consistent with a double-remove or use-after-free

- Thread stack: mtkwl6eux → ndis!NdisWaitEvent → nt!KeWaitForSingleObject

- The crash occurs when Windows' ETW subsystem enumerates threads and walks the corrupted wait list

- All dumps have identical stacks. Failure bucket: 0x139_3_CORRUPT_LIST_ENTRY_nt!KiFastFailDispatch

- Driver's internal PDB references MediaTek MT7921AU — may affect other adapters using the same chipset

Ruled out: RAM (memory diagnostic passed), other drivers (corrupted memory and thread both trace to mtkwl6eux.sys), hardware (adapter works fine without vSwitch).

Workaround: Move the Hyper-V virtual switch to a different adapter. Crashes stop.

Environment: Windows 11 Pro 24H2 Build 26100.8037 | mtkwl6eux.sys v1.0.0.125 (latest) | USB 3.0 | Hyper-V + HVCI enabled

Anyone else seen this? I've also opened a support case. Happy to share more dump details.