======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc1-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.1853/12192 is trying to acquire lock:
ffffffff900fd388 (rtnl_mutex){+.+.}-{4:4}, at: do_ip_getsockopt+0x11ae/0x2ba0 net/ipv4/ip_sockglue.c:1702

but task is already holding lock:
ffff88805ad84420 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_getsockopt+0x131/0x400 net/smc/af_smc.c:3153

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+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
       smc_switch_to_fallback+0x35/0xda0 net/smc/af_smc.c:903
       smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2781
       sock_sendmsg_nosec net/socket.c:712 [inline]
       __sock_sendmsg+0x221/0x270 net/socket.c:727
       __sys_sendto+0x365/0x4c0 net/socket.c:2180
       __do_sys_sendto net/socket.c:2187 [inline]
       __se_sys_sendto net/socket.c:2183 [inline]
       __ia32_sys_sendto+0xdd/0x100 net/socket.c:2183
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #1 (sk_lock-AF_INET){+.+.}-{0:0}:
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       lock_sock_nested+0x48/0x100 net/core/sock.c:3697
       do_ip_setsockopt+0x17e9/0x39c0 net/ipv4/ip_sockglue.c:1078
       ip_setsockopt+0x63/0x100 net/ipv4/ip_sockglue.c:1417
       do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296
       __sys_setsockopt net/socket.c:2321 [inline]
       __do_sys_setsockopt net/socket.c:2327 [inline]
       __se_sys_setsockopt net/socket.c:2324 [inline]
       __ia32_sys_setsockopt+0x1f2/0x280 net/socket.c:2324
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #0 (rtnl_mutex){+.+.}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3166 [inline]
       check_prevs_add kernel/locking/lockdep.c:3285 [inline]
       validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
       __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
       lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
       __mutex_lock_common kernel/locking/mutex.c:601 [inline]
       __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
       do_ip_getsockopt+0x11ae/0x2ba0 net/ipv4/ip_sockglue.c:1702
       ip_getsockopt+0xef/0x2e0 net/ipv4/ip_sockglue.c:1765
       tcp_getsockopt+0x16f/0x1d0 net/ipv4/tcp.c:4727
       smc_getsockopt+0x1c6/0x400 net/smc/af_smc.c:3163
       do_sock_getsockopt+0x391/0x740 net/socket.c:2357
       __sys_getsockopt net/socket.c:2386 [inline]
       __do_sys_getsockopt net/socket.c:2393 [inline]
       __se_sys_getsockopt net/socket.c:2390 [inline]
       __ia32_sys_getsockopt+0x2a1/0x370 net/socket.c:2390
       do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
       __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
       do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

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.4.1853/12192:
 #0: ffff88805ad84420 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_getsockopt+0x131/0x400 net/smc/af_smc.c:3153

stack backtrace:
CPU: 1 UID: 0 PID: 12192 Comm: syz.4.1853 Not tainted 6.15.0-rc1-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079
 check_noncircular+0x142/0x160 kernel/locking/lockdep.c:2211
 check_prev_add kernel/locking/lockdep.c:3166 [inline]
 check_prevs_add kernel/locking/lockdep.c:3285 [inline]
 validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
 __lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
 lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
 __mutex_lock_common kernel/locking/mutex.c:601 [inline]
 __mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
 do_ip_getsockopt+0x11ae/0x2ba0 net/ipv4/ip_sockglue.c:1702
 ip_getsockopt+0xef/0x2e0 net/ipv4/ip_sockglue.c:1765
 tcp_getsockopt+0x16f/0x1d0 net/ipv4/tcp.c:4727
 smc_getsockopt+0x1c6/0x400 net/smc/af_smc.c:3163
 do_sock_getsockopt+0x391/0x740 net/socket.c:2357
 __sys_getsockopt net/socket.c:2386 [inline]
 __do_sys_getsockopt net/socket.c:2393 [inline]
 __se_sys_getsockopt net/socket.c:2390 [inline]
 __ia32_sys_getsockopt+0x2a1/0x370 net/socket.c:2390
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf73dd579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f506655c EFLAGS: 00000206 ORIG_RAX: 000000000000016d
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000029 RSI: 0000000000000000 RDI: 00000000800000c0
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	90                   	nop
  31:	90                   	nop
  32:	90                   	nop
  33:	90                   	nop
  34:	90                   	nop
  35:	90                   	nop
  36:	90                   	nop
  37:	90                   	nop
  38:	90                   	nop
  39:	90                   	nop
  3a:	90                   	nop
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop