I am experiencing the same issue. It was working flawlessly for months, and now the HD can only be mounted r/o.
From looking at the console logs, it seems that there is now a segfault with the mount command:
Code:
Process: mount [2915]
Path: /sbin/mount
Identifier: mount
Version: 641.40.3
Code Type: X86-64 (Native)
Parent Process: ??? [2914]
Responsible: diskarbitrationd [154]
User ID: 0
Date/Time: 2022-03-31 20:56:20.454 +0200
OS Version: Mac OS X 10.15.7 (19H1824)
Report Version: 12
Anonymous UUID: 4A481F0B-16F7-0881-6A45-47BF6F69CF42
Time Awake Since Boot: 1600 seconds
System Integrity Protection: enabled
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_BAD_ACCESS (SIGSEGV)
Exception Codes: EXC_I386_GPFLT
Exception Note: EXC_CORPSE_NOTIFY
Termination Signal: Segmentation fault: 11
Termination Reason: Namespace SIGNAL, Code 0xb
Terminating Process: exc handler [2915]
Application Specific Information:
dyld3 mode
crashed on child side of fork pre-exec
Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0 libsystem_platform.dylib 0x00007fff733fce52 _platform_strlen + 18
1 libsystem_c.dylib 0x00007fff73294891 __vfprintf + 5379
2 libsystem_c.dylib 0x00007fff732baad3 __v2printf + 475
3 libsystem_c.dylib 0x00007fff732a0ee7 _vsnprintf + 417
4 libsystem_c.dylib 0x00007fff732a0f90 vsnprintf + 68
5 libsystem_c.dylib 0x00007fff732cf4b8 __snprintf_chk + 123
6 mount 0x000000010eca6e68 0x10eca5000 + 7784
7 mount 0x000000010eca676b 0x10eca5000 + 5995
8 libdyld.dylib 0x00007fff73202cc9 start + 1
Thread 0 crashed with X86 Thread State (64-bit):
rax: 0x2f6d65747379532f rbx: 0x0000000000000001 rcx: 0x2f6d65747379532f rdx: 0x2f6d65747379532f
rdi: 0x2f6d657473795320 rsi: 0x0000000000000001 rbp: 0x00007ffee0f594e0 rsp: 0x00007ffee0f594e0
r8: 0x0000000000000000 r9: 0x00007ffee0f59bf0 r10: 0x000000010eca7d0b r11: 0x000000010eca7d0b
r12: 0x0000000000000073 r13: 0x0000000000000000 r14: 0xffffffffffffffff r15: 0x000000010eca7d0d
rip: 0x00007fff733fce52 rfl: 0x0000000000010202 cr2: 0x00007ff6fcc03f28
Logical CPU: 4
Error Code: 0x00000000
Trap Number: 13