====================================================== WARNING: possible circular locking dependency detected 6.12.0-rc6-syzkaller-00169-g252e01e68241 #0 Not tainted ------------------------------------------------------ syz.5.1765/13271 is trying to acquire lock: ffffffff8fcd3948 (rtnl_mutex){+.+.}-{3:3}, at: start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761 but task is already holding lock: ffff88805eef38a8 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3056 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&smc->clcsock_release_lock){+.+.}-{3:3}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 smc_switch_to_fallback+0x35/0xdb0 net/smc/af_smc.c:902 smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2771 sock_sendmsg_nosec net/socket.c:729 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:744 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2607 ___sys_sendmsg net/socket.c:2661 [inline] __sys_sendmsg+0x292/0x380 net/socket.c:2690 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_INET6){+.+.}-{0:0}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 lock_sock_nested+0x48/0x100 net/core/sock.c:3611 do_ipv6_setsockopt+0xbf3/0x3630 net/ipv6/ipv6_sockglue.c:567 ipv6_setsockopt+0x5d/0x170 net/ipv6/ipv6_sockglue.c:993 do_sock_setsockopt+0x3af/0x720 net/socket.c:2334 __sys_setsockopt+0x1a2/0x250 net/socket.c:2357 __do_sys_setsockopt net/socket.c:2366 [inline] __se_sys_setsockopt net/socket.c:2363 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2363 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){+.+.}-{3:3}: 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+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761 do_ip_vs_set_ctl+0x442/0x13d0 net/netfilter/ipvs/ip_vs_ctl.c:2732 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3064 do_sock_setsockopt+0x3af/0x720 net/socket.c:2334 __sys_setsockopt+0x1a2/0x250 net/socket.c:2357 __do_sys_setsockopt net/socket.c:2366 [inline] __se_sys_setsockopt net/socket.c:2363 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2363 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_INET6 --> &smc->clcsock_release_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&smc->clcsock_release_lock); lock(sk_lock-AF_INET6); lock(&smc->clcsock_release_lock); lock(rtnl_mutex); *** DEADLOCK *** 1 lock held by syz.5.1765/13271: #0: ffff88805eef38a8 (&smc->clcsock_release_lock){+.+.}-{3:3}, at: smc_setsockopt+0x1c3/0xe50 net/smc/af_smc.c:3056 stack backtrace: CPU: 1 UID: 0 PID: 13271 Comm: syz.5.1765 Not tainted 6.12.0-rc6-syzkaller-00169-g252e01e68241 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __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+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:608 [inline] __mutex_lock+0x136/0xd70 kernel/locking/mutex.c:752 start_sync_thread+0xdc/0x2dc0 net/netfilter/ipvs/ip_vs_sync.c:1761 do_ip_vs_set_ctl+0x442/0x13d0 net/netfilter/ipvs/ip_vs_ctl.c:2732 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 smc_setsockopt+0x275/0xe50 net/smc/af_smc.c:3064 do_sock_setsockopt+0x3af/0x720 net/socket.c:2334 __sys_setsockopt+0x1a2/0x250 net/socket.c:2357 __do_sys_setsockopt net/socket.c:2366 [inline] __se_sys_setsockopt net/socket.c:2363 [inline] __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2363 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: 0033:0x7febf917e719 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:00007febf9f9b038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007febf9335f80 RCX: 00007febf917e719 RDX: 000000000000048b RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007febf91f139e R08: 0000000000000018 R09: 0000000000000000 R10: 00000000200001c0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007febf9335f80 R15: 00007fff1df0c968