devpts: called with bogus options
netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'.

=====================================
[ BUG: bad unlock balance detected! ]
4.9.67-gf26d3c7 #106 Not tainted
-------------------------------------
syz-executor2/3995 is trying to release lock ([   44.115423] netlink: 8 bytes leftover after parsing attributes in process `syz-executor6'.
mrt_lock) at:
but there are no more locks to release!

other info that might help us debug this:
2 locks held by syz-executor2/3995:
 #0:  (&f->f_pos_lock){+.+.+.}, at: [<ffffffff815cf8df>] __fdget_pos+0x9f/0xc0 fs/file.c:781
 #1:  (&p->lock){+.+.+.}, at: [<ffffffff815e4cdd>] seq_read+0xdd/0x1290 fs/seq_file.c:178

stack backtrace:
CPU: 1 PID: 3995 Comm: syz-executor2 Not tainted 4.9.67-gf26d3c7 #106
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801c68378e8 ffffffff81d906e9 ffffffff849ae8f8 ffff8801c4b46000
 ffffffff834dec54 ffffffff849ae8f8 ffff8801c4b46888 ffff8801c6837918
 ffffffff812353f4 dffffc0000000000 ffffffff849ae8f8 00000000ffffffff
Call Trace:
 [<ffffffff81d906e9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d906e9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff812353f4>] print_unlock_imbalance_bug+0x174/0x1a0 kernel/locking/lockdep.c:3398
 [<ffffffff8123dec8>] __lock_release kernel/locking/lockdep.c:3540 [inline]
 [<ffffffff8123dec8>] lock_release+0x6f8/0xb80 kernel/locking/lockdep.c:3775
 [<ffffffff838a951a>] __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
 [<ffffffff838a951a>] _raw_read_unlock+0x1a/0x50 kernel/locking/spinlock.c:255
 [<ffffffff834dec54>] ipmr_mfc_seq_stop+0xe4/0x140 net/ipv6/ip6mr.c:553
 [<ffffffff815e5683>] seq_read+0xa83/0x1290 fs/seq_file.c:283
 [<ffffffff816be32f>] proc_reg_read+0xef/0x170 fs/proc/inode.c:202
 [<ffffffff81568cb1>] do_loop_readv_writev.part.17+0x141/0x1e0 fs/read_write.c:714
 [<ffffffff8156cb20>] do_loop_readv_writev fs/read_write.c:880 [inline]
 [<ffffffff8156cb20>] do_readv_writev+0x520/0x750 fs/read_write.c:874
 [<ffffffff8156cdd4>] vfs_readv+0x84/0xc0 fs/read_write.c:898
 [<ffffffff8156cef6>] do_readv+0xe6/0x250 fs/read_write.c:924
 [<ffffffff815703e7>] SYSC_readv fs/read_write.c:1011 [inline]
 [<ffffffff815703e7>] SyS_readv+0x27/0x30 fs/read_write.c:1008
 [<ffffffff838a9985>] entry_SYSCALL_64_fastpath+0x23/0xc6