uvm_fault(0xfffffd80667e8d00, 0x668, 0, 2) -> e
kernel: page fault trap, code=0
Stopped at      pppacopen+0x1b5:        movq    %r13,0x668
    TID    PID    UID     PRFLAGS     PFLAGS  CPU  COMMAND
*409412  56551      0           0  0x4000000    0K syz-executor.1
 171429  21049      0           0  0x4000000    1  syz-executor.0
pppacopen(86338,1,2000,ffff800022ca7a48) at pppacopen+0x1b5 sys/net/if_pppx.c:1020
spec_open(ffff800027b0f098) at spec_open+0x3d7 sys/kern/spec_vnops.c:157
VOP_OPEN(fffffd8070a8e9b0,1,fffffd807f7d7840,ffff800022ca7a48) at VOP_OPEN+0x75 sys/kern/vfs_vops.c:138
vn_open(ffff800027b0f2e8,1,0) at vn_open+0x467 sys/kern/vfs_vnops.c:183
doopenat(ffff800022ca7a48,ffffff9c,20000040,0,0,ffff800027b0f4d0) at doopenat+0x26a sys/kern/vfs_syscalls.c:1128
syscall(ffff800027b0f540) at syscall+0x489 mi_syscall sys/sys/syscall_mi.h:102 [inline]
syscall(ffff800027b0f540) at syscall+0x489 sys/arch/amd64/amd64/trap.c:585
Xsyscall() at Xsyscall+0x128
end of kernel
end trace frame: 0xf75ddfc9f0, count: 8
https://www.openbsd.org/ddb.html describes the minimum info required in bug
reports.  Insufficient info makes it difficult to find and fix bugs.