login: witness: acquiring duplicate lock of same type: "&sc->sc_lock"
 1st wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:242
 2nd wsmuxlk @ /syzkaller/managers/multicore/kernel/sys/dev/wscons/wsmux.c:242
Starting stack trace...
witness_checkorder(ffff800000026fd0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe14 witness_debugger sys/kern/subr_witness.c:2650 [inline]
witness_checkorder(ffff800000026fd0,1,ffffffff81f354ca,f2,0) at witness_checkorder+0xe14 sys/kern/subr_witness.c:926
_rw_enter_read(ffff800000026fc0,ffffffff81f354ca,f2) at _rw_enter_read+0x80 sys/kern/kern_rwlock.c:102
wsmux_mux_open(ffff800000026f00,ffff800000026d50) at wsmux_mux_open+0x82 wsmux_do_open sys/dev/wscons/wsmux.c:243 [inline]
wsmux_mux_open(ffff800000026f00,ffff800000026d50) at wsmux_mux_open+0x82 sys/dev/wscons/wsmux.c:225
wsmuxopen(4500,1,2000,ffff800020b439e0) at wsmuxopen+0x179 wsmux_do_open sys/dev/wscons/wsmux.c:255 [inline]
wsmuxopen(4500,1,2000,ffff800020b439e0) at wsmuxopen+0x179 sys/dev/wscons/wsmux.c:201
spec_open(ffff800020c64be0) at spec_open+0x217 sys/kern/spec_vnops.c:158
VOP_OPEN(fffffd806ff3a6d8,1,fffffd807f7c7ae0,ffff800020b439e0) at VOP_OPEN+0x76 sys/kern/vfs_vops.c:153
vn_open(ffff800020c64dd0,1,0) at vn_open+0x4c6 sys/kern/vfs_vnops.c:174
doopenat(ffff800020b439e0,ffffff9c,20000100,0,0,ffff800020c65010) at doopenat+0x2be sys/kern/vfs_syscalls.c:1045
syscall(ffff800020c650c0) at syscall+0x5ac mi_syscall sys/sys/syscall_mi.h:99 [inline]
syscall(ffff800020c650c0) at syscall+0x5ac sys/arch/amd64/amd64/trap.c:574
Xsyscall(6,0,ffffffffffffffb1,0,4,e00bc7d1010) at Xsyscall+0x128
end of kernel
end trace frame: 0xe02c33fc3e0, count: 247
End of stack trace.
Stopped at      db_enter+0x18:  addq    $0x8,%rsp