=====================================
WARNING: bad unlock balance detected!
5.11.0-syzkaller #0 Not tainted
-------------------------------------
syz-executor112/5896 is trying to release lock (&call->user_mutex) at:
[<ffffffff875d9a97>] rxrpc_do_sendmsg+0x8b7/0x12c0 net/rxrpc/sendmsg.c:748
but there are no more locks to release!

other info that might help us debug this:
no locks held by syz-executor112/5896.

stack backtrace:
CPU: 0 PID: 5896 Comm: syz-executor112 Not tainted 5.11.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x9a/0xcc lib/dump_stack.c:120
 print_unlock_imbalance_bug include/trace/events/lock.h:58 [inline]
 __lock_release kernel/locking/lockdep.c:5111 [inline]
 lock_release.cold+0x49/0x4e kernel/locking/lockdep.c:5462
 __mutex_unlock_slowpath+0x81/0x610 kernel/locking/mutex.c:1228
 rxrpc_do_sendmsg+0x8b7/0x12c0 net/rxrpc/sendmsg.c:748
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg+0xab/0xe0 net/socket.c:672
 ____sys_sendmsg+0x5bf/0x7a0 net/socket.c:2345
 ___sys_sendmsg+0xd3/0x150 net/socket.c:2399
 __sys_sendmsg+0xb2/0x140 net/socket.c:2432
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7feaf1ec8de9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 14 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feaf1e7b318 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007feaf1f513e8 RCX: 00007feaf1ec8de9
RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007feaf1f513e0 R08: 000000000000224e R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 000000d7860cdad7
R13: 00007fffbe841fff R14: 00007feaf