panic: mtx_lock() of destroyed mutex @ /syzkaller/managers/i386/kernel/sys/netinet/sctp_pcb.c:4855
cpuid = 1
time = 1605782390
KDB: stack backtrace:
db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe0003636120
vpanic() at vpanic+0x1c7/frame 0xfffffe0003636180
panic() at panic+0x43/frame 0xfffffe00036361e0
__mtx_lock_flags() at __mtx_lock_flags+0x1e2/frame 0xfffffe0003636240
sctp_free_assoc() at sctp_free_assoc+0x83e/frame 0xfffffe00036362d0
sctp_process_control() at sctp_process_control+0x8a98/frame 0xfffffe0003636750
sctp_common_input_processing() at sctp_common_input_processing+0x7db/frame 0xfffffe00036368e0
sctp_input_with_port() at sctp_input_with_port+0x308/frame 0xfffffe00036369d0
sctp_input() at sctp_input+0x1f/frame 0xfffffe00036369f0
ip_input() at ip_input+0x388/frame 0xfffffe0003636a90
swi_net() at swi_net+0x20d/frame 0xfffffe0003636b10
ithread_loop() at ithread_loop+0x33f/frame 0xfffffe0003636bb0
fork_exit() at fork_exit+0xb3/frame 0xfffffe0003636bf0
fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe0003636bf0
--- trap 0, rip = 0, rsp = 0, rbp = 0 ---
KDB: enter: panic
[ thread pid 12 tid 100020 ]
Stopped at      kdb_enter+0x67: movq    $0,0x1478c66(%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                       0x80
rdx         0xffffffff819292d0
rbx                          0
rsp         0xfffffe0003636100
rbp         0xfffffe0003636120
rsi                        0x1
rdi                          0
r8                           0
r9                  0xffffffff
r10         0xfffffe00036367dc
r11                       0xbf
r12         0xffffffff820671c0  ddb_dbbe
r13                          0
r14         0xffffffff81975651
r15         0xffffffff81975651
rip         0xffffffff810e3717  kdb_enter+0x67
rflags                    0x86
kdb_enter+0x67: movq    $0,0x1478c66(%rip)
db>