======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0 Not tainted
------------------------------------------------------
kworker/0:6/17115 is trying to acquire lock:
ffffffff8fabfcc8 (rtnl_mutex){+.+.}-{4:4}, at: smc_vlan_by_tcpsk+0x251/0x620 net/smc/smc_core.c:1903

but task is already holding lock:
ffff888032781958 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1623 [inline]
ffff888032781958 (sk_lock-AF_INET){+.+.}-{0:0}, at: smc_connect_work+0x1ef/0xae0 net/smc/af_smc.c:1597

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_sock_nested+0x3a/0xf0 net/core/sock.c:3622
       lock_sock include/net/sock.h:1623 [inline]
       sockopt_lock_sock net/core/sock.c:1126 [inline]
       sockopt_lock_sock+0x54/0x70 net/core/sock.c:1117
       do_ip_setsockopt+0x101/0x38c0 net/ipv4/ip_sockglue.c:1078
       ip_setsockopt+0x59/0xf0 net/ipv4/ip_sockglue.c:1417
       raw_setsockopt+0xb8/0x290 net/ipv4/raw.c:845
       do_sock_setsockopt+0x222/0x480 net/socket.c:2313
       __sys_setsockopt+0x1a0/0x230 net/socket.c:2338
       __do_sys_setsockopt net/socket.c:2344 [inline]
       __se_sys_setsockopt net/socket.c:2341 [inline]
       __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2341
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (rtnl_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain kernel/locking/lockdep.c:3904 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
       smc_vlan_by_tcpsk+0x251/0x620 net/smc/smc_core.c:1903
       __smc_connect+0x466/0x4890 net/smc/af_smc.c:1517
       smc_connect_work+0x54f/0xae0 net/smc/af_smc.c:1610
       process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
       process_scheduled_works kernel/workqueue.c:3310 [inline]
       worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

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 ***

3 locks held by kworker/0:6/17115:
 #0: ffff888031005948 ((wq_completion)smc_hs_wq){+.+.}-{0:0}, at: process_one_work+0x12cd/0x1b30 kernel/workqueue.c:3204
 #1: ffffc9000427fd80 ((work_completion)(&smc->connect_work)){+.+.}-{0:0}, at: process_one_work+0x8bb/0x1b30 kernel/workqueue.c:3205
 #2: ffff888032781958 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1623 [inline]
 #2: ffff888032781958 (sk_lock-AF_INET){+.+.}-{0:0}, at: smc_connect_work+0x1ef/0xae0 net/smc/af_smc.c:1597

stack backtrace:
CPU: 0 UID: 0 PID: 17115 Comm: kworker/0:6 Not tainted 6.13.0-rc5-syzkaller-00012-g0bc21e701a6f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: smc_hs_wq smc_connect_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x41c/0x610 kernel/locking/lockdep.c:2074
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
 smc_vlan_by_tcpsk+0x251/0x620 net/smc/smc_core.c:1903
 __smc_connect+0x466/0x4890 net/smc/af_smc.c:1517
 smc_connect_work+0x54f/0xae0 net/smc/af_smc.c:1610
 process_one_work+0x958/0x1b30 kernel/workqueue.c:3229
 process_scheduled_works kernel/workqueue.c:3310 [inline]
 worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>