=====================================
WARNING: bad unlock balance detected!
4.15.0-rc7+ #255 Not tainted
-------------------------------------
syz-executor7/854 is trying to release lock (mrt_lock) at:
[<000000004dbb6ec3>] ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
but there are no more locks to release!

other info that might help us debug this:
1 lock held by syz-executor7/854:
 #0:  (&p->lock){+.+.}, at: [<000000001c790614>] seq_read+0xd5/0x13d0 fs/seq_file.c:165

stack backtrace:
CPU: 0 PID: 854 Comm: syz-executor7 Not tainted 4.15.0-rc7+ #255
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3479
 __lock_release kernel/locking/lockdep.c:3685 [inline]
 lock_release+0x6fe/0xa40 kernel/locking/lockdep.c:3933
 __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
 _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:248
 ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
 seq_read+0xc42/0x13d0 fs/seq_file.c:277
 proc_reg_read+0xef/0x170 fs/proc/inode.c:217
 __vfs_read+0xef/0xa00 fs/read_write.c:411
 vfs_read+0x11e/0x350 fs/read_write.c:447
 SYSC_pread64 fs/read_write.c:611 [inline]
 SyS_pread64+0x15b/0x190 fs/read_write.c:598
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f7c831a4c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000011
RAX: ffffffffffffffda RBX: 00007f7c831a5700 RCX: 0000000000452ac9
RDX: 0000000000000055 RSI: 0000000020de8000 RDI: 0000000000000013
RBP: 0000000000a2f870 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007f7c831a59c0 R15: 0000000000000002
BUG: sleeping function called from invalid context at lib/usercopy.c:25
in_atomic(): 1, irqs_disabled(): 0, pid: 854, name: syz-executor7
INFO: lockdep is turned off.
CPU: 0 PID: 854 Comm: syz-executor7 Not tainted 4.15.0-rc7+ #255
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
binder: 856:861 got transaction with invalid offset (0, min 0 max 24) or object.
binder: 856:861 transaction failed 29201/-22, size 24-8 line 2966
binder_alloc: binder_alloc_mmap_handler: 856 20000000-20002000 already mapped failed -16
binder: BINDER_SET_CONTEXT_MGR already set
binder: 856:861 ioctl 40046207 0 returned -16
binder_alloc: 856: binder_alloc_buf, no vma
binder: 856:862 transaction failed 29189/-3, size 24-8 line 2903
binder: undelivered TRANSACTION_ERROR: 29189
binder: undelivered TRANSACTION_ERROR: 29201
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060
 __might_sleep+0x95/0x190 kernel/sched/core.c:6013
 __might_fault+0xab/0x1d0 mm/memory.c:4526
 _copy_to_user+0x2c/0xc0 lib/usercopy.c:25
 copy_to_user include/linux/uaccess.h:155 [inline]
 seq_read+0xcb4/0x13d0 fs/seq_file.c:279
 proc_reg_read+0xef/0x170 fs/proc/inode.c:217
 __vfs_read+0xef/0xa00 fs/read_write.c:411
 vfs_read+0x11e/0x350 fs/read_write.c:447
 SYSC_pread64 fs/read_write.c:611 [inline]
 SyS_pread64+0x15b/0x190 fs/read_write.c:598
 entry_SYSCALL_64_fastpath+0x23/0x9a
RIP: 0033:0x452ac9
RSP: 002b:00007f7c831a4c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000011
RAX: ffffffffffffffda RBX: 00007f7c831a5700 RCX: 0000000000452ac9
RDX: 0000000000000055 RSI: 0000000020de8000 RDI: 0000000000000013
RBP: 0000000000a2f870 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a2f7ef R14: 00007f7c831a59c0 R15: 0000000000000002
WARNING: CPU: 0 PID: 854 at lib/usercopy.c:26 _copy_to_user+0xb5/0xc0 lib/usercopy.c:26