login: panic: mtx_lock() of destroyed mutex @ /syzkaller/managers/i386/kernel/sys/kern/sys_socket.c:309 cpuid = 0 time = 1570029374 KDB: stack backtrace: db_trace_self_wrapper() at db_trace_self_wrapper+0x47/frame 0xfffffe00246cc650 vpanic() at vpanic+0x1e0/frame 0xfffffe00246cc6b0 panic() at panic+0x43/frame 0xfffffe00246cc710 __mtx_lock_flags() at __mtx_lock_flags+0x1e2/frame 0xfffffe00246cc770 soo_stat() at soo_stat+0x9c/frame 0xfffffe00246cc7b0 kern_fstat() at kern_fstat+0xed/frame 0xfffffe00246cc800 freebsd11_freebsd32_fstat() at freebsd11_freebsd32_fstat+0x2d/frame 0xfffffe00246cc970 ia32_syscall() at ia32_syscall+0x46a/frame 0xfffffe00246ccab0 int0x80_syscall_common() at int0x80_syscall_common+0x9c/frame 0x8142660 KDB: enter: panic [ thread pid 948 tid 100513 ] Stopped at kdb_enter+0x6a: movq $0,kdb_why