login: panic: mtx_lock() of spin mutex (null) @ /syzkaller/managers/main/kernel/sys/netinet/tcp_output.c:352
cpuid = 1
time = 1601841451
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0025e72660
vpanic() at vpanic+0x1c7/frame 0xfffffe0025e726c0
panic() at panic+0x43/frame 0xfffffe0025e72720
__mtx_lock_flags() at __mtx_lock_flags+0x202/frame 0xfffffe0025e72780
tcp_output() at tcp_output+0x717/frame 0xfffffe0025e72950
tcp_usr_connect() at tcp_usr_connect+0x258/frame 0xfffffe0025e729c0
soconnectat() at soconnectat+0x183/frame 0xfffffe0025e72a20
kern_connectat() at kern_connectat+0x1e1/frame 0xfffffe0025e72a80
sys_connect() at sys_connect+0xd9/frame 0xfffffe0025e72ac0
amd64_syscall() at amd64_syscall+0x25e/frame 0xfffffe0025e72bf0
fast_syscall_common() at fast_syscall_common+0xf8/frame 0xfffffe0025e72bf0
--- syscall (198, FreeBSD ELF64, nosys), rip = 0x2838ca, rsp = 0x7fffdfffdf08, rbp = 0x7fffdfffdf70 ---
KDB: enter: panic
[ thread pid 7250 tid 100181 ]
Stopped at      kdb_enter+0x67: movq    $0,0x1480d96(%rip)
db> 
db> set $lines = 0
db> set $maxwidth = 0
db> show registers
cs                        0x20
ds                        0x3b  ll+0x1a
es                        0x3b  ll+0x1a
fs                        0x13
gs                        0x1b
ss                        0x28  ll+0x7
rax                       0x12
rcx                       0x80  ll+0x5f
rdx         0xffffffff818928e9
rbx                          0
rsp         0xfffffe0025e72640
rbp         0xfffffe0025e72660
rsi                        0x1
rdi                          0
r8                           0
r9                  0xffffffff
r10                 0x489c6dfe
r11                 0xf4f789de
r12         0xffffffff82066ae0  ddb_dbbe
r13                          0
r14         0xffffffff819377eb
r15         0xffffffff819377eb
rip         0xffffffff810d12e7  kdb_enter+0x67
rflags                    0x86  ll+0x65
kdb_enter+0x67: movq    $0,0x1480d96(%rip)
db> show proc
Process 7250 (syz-executor.1) at 0xfffff80019aed520:
 state: NORMAL
 uid: 0  gids: 0, 0, 5
 parent: pid 774 at 0xfffff800198f1000
 ABI: FreeBSD ELF64
 arguments: /root/syz-executor.1
 reaper: 0xfffff80004312000 reapsubtree: 1
 sigparent: 20
 vmspace: 0xfffffe00258213d0
   (map 0xfffffe00258213d0)
   (map.pmap 0xfffffe0025821490)
   (pmap 0xfffffe00258214f0)
 threads: 3
100165                   RunQ                                syz-executor.1
100181                   Run     CPU 1                       syz-executor.1
100183                   S       umtxn   0xfffff80019b3f980  syz-executor.1
db>