======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc2-syzkaller-00485-gc1bad69f8baf #0 Not tainted
------------------------------------------------------
syz.3.2944/16130 is trying to acquire lock:
ffffffff8fcb2008 (rtnl_mutex){+.+.}-{4:4}, at: do_ipv6_setsockopt+0x9e8/0x3640 net/ipv6/ipv6_sockglue.c:566

but task is already holding lock:
ffff88807e5c1628 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3059

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       smc_switch_to_fallback+0x35/0xd90 net/smc/af_smc.c:903
       smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2774
       sock_sendmsg_nosec net/socket.c:711 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:726
       __sys_sendto+0x363/0x4c0 net/socket.c:2208
       __do_sys_sendto net/socket.c:2215 [inline]
       __se_sys_sendto net/socket.c:2211 [inline]
       __x64_sys_sendto+0xde/0x100 net/socket.c:2211
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       lock_sock_nested+0x48/0x100 net/core/sock.c:3642
       do_ip_setsockopt+0x1a2d/0x3cd0 net/ipv4/ip_sockglue.c:1078
       ip_setsockopt+0x63/0x100 net/ipv4/ip_sockglue.c:1417
       do_sock_setsockopt+0x3af/0x720 net/socket.c:2324
       __sys_setsockopt net/socket.c:2349 [inline]
       __do_sys_setsockopt net/socket.c:2355 [inline]
       __se_sys_setsockopt net/socket.c:2352 [inline]
       __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 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+0x18ef/0x5920 kernel/locking/lockdep.c:3904
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
       __mutex_lock_common kernel/locking/mutex.c:585 [inline]
       __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
       do_ipv6_setsockopt+0x9e8/0x3640 net/ipv6/ipv6_sockglue.c:566
       ipv6_setsockopt+0x5d/0x170 net/ipv6/ipv6_sockglue.c:993
       smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3067
       do_sock_setsockopt+0x3af/0x720 net/socket.c:2324
       __sys_setsockopt net/socket.c:2349 [inline]
       __do_sys_setsockopt net/socket.c:2355 [inline]
       __se_sys_setsockopt net/socket.c:2352 [inline]
       __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

Chain exists of:
  rtnl_mutex --> sk_lock-AF_INET --> &smc->clcsock_release_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&smc->clcsock_release_lock);
                               lock(sk_lock-AF_INET);
                               lock(&smc->clcsock_release_lock);
  lock(rtnl_mutex);

 *** DEADLOCK ***

1 lock held by syz.3.2944/16130:
 #0: ffff88807e5c1628 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3059

stack backtrace:
CPU: 1 UID: 0 PID: 16130 Comm: syz.3.2944 Not tainted 6.13.0-rc2-syzkaller-00485-gc1bad69f8baf #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 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+0x18ef/0x5920 kernel/locking/lockdep.c:3904
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5226
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0x1ac/0xee0 kernel/locking/mutex.c:735
 do_ipv6_setsockopt+0x9e8/0x3640 net/ipv6/ipv6_sockglue.c:566
 ipv6_setsockopt+0x5d/0x170 net/ipv6/ipv6_sockglue.c:993
 smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3067
 do_sock_setsockopt+0x3af/0x720 net/socket.c:2324
 __sys_setsockopt net/socket.c:2349 [inline]
 __do_sys_setsockopt net/socket.c:2355 [inline]
 __se_sys_setsockopt net/socket.c:2352 [inline]
 __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2352
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f76fb385d29
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f76fc1bc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f76fb575fa0 RCX: 00007f76fb385d29
RDX: 0000000000000014 RSI: 0000000000000029 RDI: 0000000000000008
RBP: 00007f76fb401a20 R08: 0000000000000014 R09: 0000000000000000
R10: 0000000020000680 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f76fb575fa0 R15: 00007fff79dcae58
 </TASK>