Page fault in midi/sequencer.c

I can trigger this on 13.0-CURRENT r339445 with a non-root test program:

Calling uiomove() with the following non-sleepable locks held:
exclusive sleep mutex seqflq (seqflq) r = 0 (0xfffff80003860c08) locked _at_ dev/sound/midi/sequencer.c:952
stack backtrace:
#0 0xffffffff80bfe263 at witness_debugger+0x73
#1 0xffffffff80bff1b8 at witness_warn+0x448
#2 0xffffffff80bf6a91 at uiomove_faultflag+0x71
#3 0xffffffff809439e6 at mseq_write+0x4c6
#4 0xffffffff80a4f725 at devfs_write_f+0x185
#5 0xffffffff80c02a87 at dofilewrite+0x97
#6 0xffffffff80c0287f at kern_pwritev+0x5f
#7 0xffffffff80c0277d at sys_pwrite+0x8d
#8 0xffffffff81070af7 at amd64_syscall+0x2a7
#9 0xffffffff8104a4ad at fast_syscall_common+0x101
Kernel page fault with the following non-sleepable locks held:
exclusive sleep mutex seqflq (seqflq) r = 0 (0xfffff80003860c08) locked _at_ dev/sound/midi/sequencer.c:952
stack backtrace:
#0 0xffffffff80bfe263 at witness_debugger+0x73
#1 0xffffffff80bff1b8 at witness_warn+0x448
#2 0xffffffff810700d3 at trap_pfault+0x53
#3 0xffffffff8106f70a at trap+0x2ba
#4 0xffffffff81049bc5 at calltrap+0x8
#5 0xffffffff80bf6b42 at uiomove_faultflag+0x122
#6 0xffffffff809439e6 at mseq_write+0x4c6
#7 0xffffffff80a4f725 at devfs_write_f+0x185
#8 0xffffffff80c02a87 at dofilewrite+0x97
#9 0xffffffff80c0287f at kern_pwritev+0x5f
#10 0xffffffff80c0277d at sys_pwrite+0x8d
#11 0xffffffff81070af7 at amd64_syscall+0x2a7
#12 0xffffffff8104a4ad at fast_syscall_common+0x101


Fatal trap 12: page fault while in kernel mode
cpuid = 4; apic id = 04
fault virtual address = 0x20ea6b
fault code  = supervisor read data, page not present
instruction pointer = 0x20:0xffffffff8106d32d
stack pointer         = 0x28:0xfffffe00a844a660
frame pointer         = 0x28:0xfffffe00a844a660
code segment  = base 0x0, limit 0xfffff, type 0x1b
   = DPL 0, pres 1, long 1, def32 0, gran 1
processor eflags = interrupt enabled, resume, IOPL = 0
current process  = 2356 (xxx)
[ thread pid 2356 tid 100278 ]
Stopped at      copyin_nosmap_erms+0xdd:        movl    (%rsi),%edx
db>

-- 
Peter