=====================================
[ BUG: bad unlock balance detected! ]
4.4.113-g202e079 #1 Not tainted
-------------------------------------
syz-executor4/5860 is trying to release lock (mrt_lock) at:
[<ffffffff833c5524>] ipmr_mfc_seq_stop+0xe4/0x140 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-executor4/5860:
 #0:  (&p->lock){+.+.+.}, at: [<ffffffff8158c14d>] seq_read+0xdd/0x1270 fs/seq_file.c:178

stack backtrace:
 ffff8800b6947b30 ffffffff81605d55 ffffffff812363c0
Call Trace:
 [<ffffffff81d0278d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0278d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81605d55>] handle_userfault+0x715/0xf50 fs/userfaultfd.c:316
 [<ffffffff814a1ca8>] do_anonymous_page mm/memory.c:2731 [inline]
 [<ffffffff814a1ca8>] handle_pte_fault mm/memory.c:3295 [inline]
 [<ffffffff814a1ca8>] __handle_mm_fault mm/memory.c:3426 [inline]
 [<ffffffff814a1ca8>] handle_mm_fault+0x2938/0x3190 mm/memory.c:3455
 [<ffffffff810dc6cb>] __do_page_fault+0x35b/0xa00 arch/x86/mm/fault.c:1245
 [<ffffffff810dcd97>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1308
 [<ffffffff83772f88>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1033
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98
CPU: 1 PID: 5860 Comm: syz-executor4 Not tainted 4.4.113-g202e079 #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 0f5c9f0b1c733cb1 ffff8801c57b7930 ffffffff81d0278d
 ffffffff84771c18 ffff8801c57a17c0 ffffffff833c5524 ffffffff84771c18
 ffff8801c57a2008 ffff8801c57b7960 ffffffff81232314 dffffc0000000000
Call Trace:
 [<ffffffff81d0278d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0278d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81232314>] print_unlock_imbalance_bug+0x174/0x1a0 kernel/locking/lockdep.c:3266
 [<ffffffff8123d1aa>] __lock_release kernel/locking/lockdep.c:3408 [inline]
 [<ffffffff8123d1aa>] lock_release+0x72a/0xc10 kernel/locking/lockdep.c:3611
 [<ffffffff8377145a>] __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
 [<ffffffff8377145a>] _raw_read_unlock+0x1a/0x50 kernel/locking/spinlock.c:255
 [<ffffffff833c5524>] ipmr_mfc_seq_stop+0xe4/0x140 net/ipv6/ip6mr.c:553
 [<ffffffff8158caf0>] seq_read+0xa80/0x1270 fs/seq_file.c:283
 [<ffffffff8166479f>] proc_reg_read+0xef/0x170 fs/proc/inode.c:202
 [<ffffffff8151c561>] do_loop_readv_writev+0x141/0x1e0 fs/read_write.c:680
 [<ffffffff8151e8bd>] do_readv_writev+0x5dd/0x6e0 fs/read_write.c:810
 [<ffffffff8151ea38>] vfs_readv+0x78/0xb0 fs/read_write.c:834
 [<ffffffff815212a9>] SYSC_preadv fs/read_write.c:912 [inline]
 [<ffffffff815212a9>] SyS_preadv+0x199/0x230 fs/read_write.c:898
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 5870 Comm: syz-executor1 Not tainted 4.4.113-g202e079 #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 39407dbaf2ae3ce6 ffff8801c56f7980 ffffffff81d0278d
 ffff8801d4aa0d80 1ffff10038adef3d ffff8801c56f7b08 0000000000000000
 0000000000000000 ffff8801c56f7b30 ffffffff81605d55 ffffffff812363c0
Call Trace:
 [<ffffffff81d0278d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0278d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81605d55>] handle_userfault+0x715/0xf50 fs/userfaultfd.c:316
 [<ffffffff814a1ca8>] do_anonymous_page mm/memory.c:2731 [inline]
 [<ffffffff814a1ca8>] handle_pte_fault mm/memory.c:3295 [inline]
 [<ffffffff814a1ca8>] __handle_mm_fault mm/memory.c:3426 [inline]
 [<ffffffff814a1ca8>] handle_mm_fault+0x2938/0x3190 mm/memory.c:3455
 [<ffffffff810dc6cb>] __do_page_fault+0x35b/0xa00 arch/x86/mm/fault.c:1245
 [<ffffffff810dcd97>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1308
 [<ffffffff83772f88>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1033
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98
syz-executor7 uses obsolete (PF_INET,SOCK_PACKET)
audit: type=1400 audit(1517163977.463:19): avc:  denied  { setattr } for  pid=5935 comm="syz-executor5" name="fdinfo" dev="proc" ino=12911 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=dir permissive=1
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 1 PID: 6065 Comm: syz-executor3 Not tainted 4.4.113-g202e079 #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 cdc0b3b3973e30df ffff8800b5337580 ffffffff81d0278d
 ffff8801d4aa1200 1ffff10016a66ebd ffff8800b5337708 0000000000000000
 0000000000000000 ffff8800b5337730 ffffffff81605d55 ffffffff812363c0
Call Trace:
 [<ffffffff81d0278d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0278d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81605d55>] handle_userfault+0x715/0xf50 fs/userfaultfd.c:316
 [<ffffffff814a1ca8>] do_anonymous_page mm/memory.c:2731 [inline]
 [<ffffffff814a1ca8>] handle_pte_fault mm/memory.c:3295 [inline]
 [<ffffffff814a1ca8>] __handle_mm_fault mm/memory.c:3426 [inline]
 [<ffffffff814a1ca8>] handle_mm_fault+0x2938/0x3190 mm/memory.c:3455
 [<ffffffff810dc6cb>] __do_page_fault+0x35b/0xa00 arch/x86/mm/fault.c:1245
 [<ffffffff810dcd97>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1308
 [<ffffffff83772f88>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1033
 [<ffffffff8141dcbb>] generic_perform_write+0x1eb/0x530 mm/filemap.c:2540
 [<ffffffff814242da>] __generic_file_write_iter+0x35a/0x580 mm/filemap.c:2675
 [<ffffffff814247f1>] generic_file_write_iter+0x2f1/0x720 mm/filemap.c:2703
 [<ffffffff8151c30c>] new_sync_write fs/read_write.c:478 [inline]
 [<ffffffff8151c30c>] __vfs_write+0x33c/0x450 fs/read_write.c:491
 [<ffffffff8151df3a>] vfs_write+0x18a/0x530 fs/read_write.c:538
 [<ffffffff81520629>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff81520629>] SyS_write+0xd9/0x1b0 fs/read_write.c:577
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 1 PID: 6065 Comm: syz-executor3 Not tainted 4.4.113-g202e079 #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 0000000000000000 cdc0b3b3973e30df ffff8800b5337580 ffffffff81d0278d
 ffff8801d4aa1380 1ffff10016a66ebd ffff8800b5337708 0000000000000000
 0000000000000000 ffff8800b5337730 ffffffff81605d55 ffffffff812363c0
Call Trace:
 [<ffffffff81d0278d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d0278d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff81605d55>] handle_userfault+0x715/0xf50 fs/userfaultfd.c:316
 [<ffffffff814a1ca8>] do_anonymous_page mm/memory.c:2731 [inline]
 [<ffffffff814a1ca8>] handle_pte_fault mm/memory.c:3295 [inline]
 [<ffffffff814a1ca8>] __handle_mm_fault mm/memory.c:3426 [inline]
 [<ffffffff814a1ca8>] handle_mm_fault+0x2938/0x3190 mm/memory.c:3455
 [<ffffffff810dc6cb>] __do_page_fault+0x35b/0xa00 arch/x86/mm/fault.c:1245
 [<ffffffff810dcd97>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1308
 [<ffffffff83772f88>] page_fault+0x28/0x30 arch/x86/entry/entry_64.S:1033
 [<ffffffff8141dcbb>] generic_perform_write+0x1eb/0x530 mm/filemap.c:2540
 [<ffffffff814242da>] __generic_file_write_iter+0x35a/0x580 mm/filemap.c:2675
 [<ffffffff814247f1>] generic_file_write_iter+0x2f1/0x720 mm/filemap.c:2703
 [<ffffffff8151c30c>] new_sync_write fs/read_write.c:478 [inline]
 [<ffffffff8151c30c>] __vfs_write+0x33c/0x450 fs/read_write.c:491
 [<ffffffff8151df3a>] vfs_write+0x18a/0x530 fs/read_write.c:538
 [<ffffffff81520629>] SYSC_write fs/read_write.c:585 [inline]
 [<ffffffff81520629>] SyS_write+0xd9/0x1b0 fs/read_write.c:577
 [<ffffffff83771b5f>] entry_SYSCALL_64_fastpath+0x1c/0x98
audit: type=1400 audit(1517163979.783:20): avc:  denied  { setattr } for  pid=6370 comm="syz-executor4" name="mountinfo" dev="proc" ino=13354 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=file permissive=1