panic: vm_page_free_prep: attempting to free a PG_NOFREE page
cpuid = 1
time = 1732002718
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0xc6/frame 0xfffffe0081af3070
kdb_backtrace() at kdb_backtrace+0xd0/frame 0xfffffe0081af31d0
vpanic() at vpanic+0x257/frame 0xfffffe0081af3390
panic() at panic+0xb5/frame 0xfffffe0081af3460
vm_page_free_prep() at vm_page_free_prep+0x66d/frame 0xfffffe0081af34c0
vm_page_free_toq() at vm_page_free_toq+0x1e/frame 0xfffffe0081af3500
_kmem_unback() at _kmem_unback+0x201/frame 0xfffffe0081af3550
kmem_back_domain() at kmem_back_domain+0x3de/frame 0xfffffe0081af35d0
kmem_malloc_domainset() at kmem_malloc_domainset+0x1c9/frame 0xfffffe0081af3710
keg_alloc_slab() at keg_alloc_slab+0x1f1/frame 0xfffffe0081af3830
zone_import() at zone_import+0x2d9/frame 0xfffffe0081af3a10
zone_alloc_item() at zone_alloc_item+0x16a/frame 0xfffffe0081af3af0
fork1() at fork1+0xa8a/frame 0xfffffe0081af3c10
sys_fork() at sys_fork+0xe3/frame 0xfffffe0081af3d10
ia32_syscall() at ia32_syscall+0x488/frame 0xfffffe0081af3f30
int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0xdfffcf98
KDB: enter: panic
[ thread pid 3605 tid 103776 ]
Stopped at      kdb_enter+0x6e: movq    $0,0x23eb8d7(%rip)
db> 
db> set $lines = 0
db> set $maxwidth = 0
db> show registers
cs                        0x20
ds                        0x3b
es                        0x3b
fs                        0x13
gs                        0x1b
ss                           0
rax                       0x12
rcx         0xfffffe00033eee30
rdx                          0
rbx         0xffffffff82728720  .str.27
rsp         0xfffffe0081af31b0
rbp         0xfffffe0081af31d0
rsi                          0
rdi         0xffffffff815d0e59  printf+0x149
r8                           0
r9                  0xffffffff
r10                        0x7
r11                        0x6
r12         0xfffffe0080ff2000
r13         0xfffffffffffffffd
r14         0xffffffff82728720  .str.27
r15                          0
rip         0xffffffff815ba73e  kdb_enter+0x6e
rflags                    0x46
kdb_enter+0x6e: movq    $0,0x23eb8d7(%rip)
db> show proc
Process 3605 (syz-executor) at 0xfffffe0080fe4560:
 state: NORMAL
 uid: 0  gids: 0, 0, 5
 parent: pid 2101 at 0xfffffe007cc58020
 ABI: FreeBSD ELF32
 flag: 0x10000000  flag2: 0
 arguments: ./syz-executor exec
 reaper: 0xfffffe0007a07040 reapsubtree: 1
 sigparent: 20
 vmspace: 0xfffffe0080fefc08
   (map 0xfffffe0080fefc08)
   (map.pmap 0xfffffe0080fefcc8)
   (pmap 0xfffffe0080fefd38)
 threads: 1
103776                   Run     CPU 1                       syz-executor
db>