panic: negative vmsize for uid 60929

cpuid = 1
time = 5
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0xc6/frame 0xfffffe005752e1d0
kdb_backtrace() at kdb_backtrace+0xd0/frame 0xfffffe005752e330
vpanic() at vpanic+0x257/frame 0xfffffe005752e4f0
panic() at panic+0xb5/frame 0xfffffe005752e5b0
swap_release_by_cred() at swap_release_by_cred+0x14f/frame 0xfffffe005752e5f0
vm_map_entry_delete() at vm_map_entry_delete+0xca/frame 0xfffffe005752e670
vm_map_delete() at vm_map_delete+0x530/frame 0xfffffe005752e7b0
vm_map_fixed() at vm_map_fixed+0x181/frame 0xfffffe005752e890
vm_mmap_object() at vm_mmap_object+0x324/frame 0xfffffe005752e930
shm_mmap() at shm_mmap+0x539/frame 0xfffffe005752ea70
kern_mmap() at kern_mmap+0xedd/frame 0xfffffe005752ec10
sys_mmap() at sys_mmap+0x153/frame 0xfffffe005752ed10
amd64_syscall() at amd64_syscall+0x4af/frame 0xfffffe005752ef30
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe005752ef30
--- syscall (198, FreeBSD ELF64, __syscall), rip = 0x3a197a, rsp = 0x826ca0f08, rbp = 0x826ca0f80 ---
KDB: enter: panic
[ thread pid 913 tid 100235 ]
Stopped at      kdb_enter+0x6e: movq    $0,0x25be387(%rip)
db> 
db> set $lines = 0
db> set $maxwidth = 0
db>