======================================================
[ INFO: possible circular locking dependency detected ]
4.9.96-g71fce1e #10 Not tainted
-------------------------------------------------------
syz-executor6/12168 is trying to acquire lock:
 ([  117.236599] BTRFS: device fsid ecf6f2a3-2997-48ae-b81e-1b00920efd9a 
devid 1 transid 5 /dev/loop7
but task is already holding lock:
 (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff83340fd9>] lock_sock include/net/sock.h:1404 [inline]
 (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff83340fd9>] do_ip_setsockopt.isra.13+0x269/0x2b10 net/ipv4/ip_sockglue.c:638
which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

       lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
       lock_sock_nested+0xc6/0x120 net/core/sock.c:2511
       lock_sock include/net/sock.h:1404 [inline]
       do_ip_setsockopt.isra.13+0x12a/0x2b10 net/ipv4/ip_sockglue.c:638
       ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1242
       tcp_setsockopt+0x88/0xe0 net/ipv4/tcp.c:2755
       sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706
       SYSC_setsockopt net/socket.c:1772 [inline]
       SyS_setsockopt+0x166/0x260 net/socket.c:1751
       do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
       entry_SYSCALL_64_after_swapgs+0x5d/0xdb

       check_prev_add kernel/locking/lockdep.c:1828 [inline]
       check_prevs_add kernel/locking/lockdep.c:1938 [inline]
       validate_chain kernel/locking/lockdep.c:2265 [inline]
       __lock_acquire+0x3019/0x4070 kernel/locking/lockdep.c:3345
       lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
       __mutex_lock_common kernel/locking/mutex.c:521 [inline]
       mutex_lock_nested+0xc0/0x870 kernel/locking/mutex.c:621
       rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
       mrtsock_destruct+0x3b/0x1e0 net/ipv4/ipmr.c:1231
       ip_ra_control+0x2c2/0x420 net/ipv4/ip_sockglue.c:360
       do_ip_setsockopt.isra.13+0x15ff/0x2b10 net/ipv4/ip_sockglue.c:1139
       ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1242
       raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:833
       sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706
       SYSC_setsockopt net/socket.c:1772 [inline]
       SyS_setsockopt+0x166/0x260 net/socket.c:1751
       do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
       entry_SYSCALL_64_after_swapgs+0x5d/0xdb

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_INET);
                               lock(rtnl_mutex);
                               lock(sk_lock-AF_INET);
  lock(rtnl_mutex);

 *** DEADLOCK ***

1 lock held by syz-executor6/12168:
 #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff83340fd9>] lock_sock include/net/sock.h:1404 [inline]
 #0:  (sk_lock-AF_INET){+.+.+.}, at: [<ffffffff83340fd9>] do_ip_setsockopt.isra.13+0x269/0x2b10 net/ipv4/ip_sockglue.c:638

stack backtrace:
CPU: 0 PID: 12168 Comm: syz-executor6 Not tainted 4.9.96-g71fce1e #10
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801b8d675f8 ffffffff81eb0b69 ffffffff8539cf30 ffffffff853e7690
 ffffffff8539cf30 ffff8801be1720e8 ffff8801be171800 ffff8801b8d67640
 ffffffff814242fd 0000000000000001 00000000be171800 0000000000000001
Call Trace:
 [<ffffffff81eb0b69>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81eb0b69>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff814242fd>] print_circular_bug.cold.51+0x1bd/0x27d kernel/locking/lockdep.c:1202
 [<ffffffff81237399>] check_prev_add kernel/locking/lockdep.c:1828 [inline]
 [<ffffffff81237399>] check_prevs_add kernel/locking/lockdep.c:1938 [inline]
 [<ffffffff81237399>] validate_chain kernel/locking/lockdep.c:2265 [inline]
 [<ffffffff81237399>] __lock_acquire+0x3019/0x4070 kernel/locking/lockdep.c:3345
 [<ffffffff81238e60>] lock_acquire+0x130/0x3e0 kernel/locking/lockdep.c:3756
 [<ffffffff839e85b0>] __mutex_lock_common kernel/locking/mutex.c:521 [inline]
 [<ffffffff839e85b0>] mutex_lock_nested+0xc0/0x870 kernel/locking/mutex.c:621
 [<ffffffff830b06a7>] rtnl_lock+0x17/0x20 net/core/rtnetlink.c:70
 [<ffffffff8347feab>] mrtsock_destruct+0x3b/0x1e0 net/ipv4/ipmr.c:1231
 [<ffffffff83340c12>] ip_ra_control+0x2c2/0x420 net/ipv4/ip_sockglue.c:360
 [<ffffffff8334236f>] do_ip_setsockopt.isra.13+0x15ff/0x2b10 net/ipv4/ip_sockglue.c:1139
 [<ffffffff833438ba>] ip_setsockopt+0x3a/0xb0 net/ipv4/ip_sockglue.c:1242
 [<ffffffff833e52c7>] raw_setsockopt+0xb7/0xd0 net/ipv4/raw.c:833
 [<ffffffff8301875a>] sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:2706
 [<ffffffff83015516>] SYSC_setsockopt net/socket.c:1772 [inline]
 [<ffffffff83015516>] SyS_setsockopt+0x166/0x260 net/socket.c:1751
 [<ffffffff81006316>] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282
 [<ffffffff839f3313>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb
BTRFS error (device loop7): superblock checksum mismatch
BTRFS error (device loop7): open_ctree failed
BTRFS error (device loop7): superblock checksum mismatch
BTRFS error (device loop7): open_ctree failed
BTRFS error (device loop7): superblock checksum mismatch
BTRFS error (device loop7): open_ctree failed
BTRFS error (device loop7): superblock checksum mismatch
BTRFS error (device loop7): open_ctree failed
BTRFS error (device loop7): superblock checksum mismatch
BTRFS error (device loop7): open_ctree failed