login: panic: mtx_lock() of destroyed mutex @ /syzkaller/managers/i386/kernel/sys/kern/sys_socket.c:309 cpuid = 1 time = 1569912382 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00246a15f0 vpanic() at vpanic+0x1e0/frame 0xfffffe00246a1650 panic() at panic+0x43/frame 0xfffffe00246a16b0 __mtx_lock_flags() at __mtx_lock_flags+0x1e2/frame 0xfffffe00246a1710 soo_stat() at soo_stat+0x9c/frame 0xfffffe00246a1750 kern_fstat() at kern_fstat+0xed/frame 0xfffffe00246a17a0 freebsd32_fstat() at freebsd32_fstat+0x2b/frame 0xfffffe00246a1970 ia32_syscall() at ia32_syscall+0x46a/frame 0xfffffe00246a1ab0 int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0x814266a KDB: enter: panic [ thread pid 882 tid 100544 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why