IPVS: stopping backup sync thread 6569 ... ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc3-syzkaller-00293-g5cf80612d3f7 #0 Not tainted ------------------------------------------------------ syz.2.307/6568 is trying to acquire lock: ffffffff8fef6fa8 (rtnl_mutex){+.+.}-{4:4}, at: ip_mc_drop_socket+0x9b/0x290 net/ipv4/igmp.c:2784 but task is already holding lock: ffff888059258aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x101/0xa00 net/smc/af_smc.c:3073 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&smc->clcsock_release_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 smc_switch_to_fallback+0x2d/0xa00 net/smc/af_smc.c:903 smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] __sys_sendto+0x488/0x4f0 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2190 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 -> #1 (sk_lock-AF_INET){+.+.}-{0:0}: lock_sock_nested+0x3a/0xf0 net/core/sock.c:3645 lock_sock include/net/sock.h:1624 [inline] gtp_encap_enable_socket+0x288/0x4f0 drivers/net/gtp.c:1674 gtp_encap_enable drivers/net/gtp.c:1708 [inline] gtp_newlink+0xec3/0x12f0 drivers/net/gtp.c:1511 rtnl_newlink_create net/core/rtnetlink.c:3796 [inline] __rtnl_newlink net/core/rtnetlink.c:3907 [inline] rtnl_newlink+0xb95/0x1d60 net/core/rtnetlink.c:4022 rtnetlink_rcv_msg+0x95b/0xea0 net/core/rtnetlink.c:6912 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg net/socket.c:733 [inline] ____sys_sendmsg+0xaaf/0xc90 net/socket.c:2573 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2627 __sys_sendmsg+0x16e/0x220 net/socket.c:2659 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:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ip_mc_drop_socket+0x9b/0x290 net/ipv4/igmp.c:2784 inet_release+0xa3/0x280 net/ipv4/af_inet.c:422 __sock_release net/socket.c:647 [inline] sock_release+0x8e/0x1d0 net/socket.c:675 stop_sync_thread+0x285/0x720 net/netfilter/ipvs/ip_vs_sync.c:2004 do_ip_vs_set_ctl+0x4ec/0x11c0 net/netfilter/ipvs/ip_vs_ctl.c:2734 nf_setsockopt+0x8a/0xf0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424 tcp_setsockopt+0xa4/0x100 net/ipv4/tcp.c:4049 smc_setsockopt+0x1b4/0xa00 net/smc/af_smc.c:3081 do_sock_setsockopt+0x222/0x480 net/socket.c:2303 __sys_setsockopt+0x1a0/0x230 net/socket.c:2328 __do_sys_setsockopt net/socket.c:2334 [inline] __se_sys_setsockopt net/socket.c:2331 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2331 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 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.2.307/6568: #0: ffff888059258aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x101/0xa00 net/smc/af_smc.c:3073 stack backtrace: CPU: 1 UID: 0 PID: 6568 Comm: syz.2.307 Not tainted 6.14.0-rc3-syzkaller-00293-g5cf80612d3f7 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2208 check_prev_add kernel/locking/lockdep.c:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain kernel/locking/lockdep.c:3906 [inline] __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 ip_mc_drop_socket+0x9b/0x290 net/ipv4/igmp.c:2784 inet_release+0xa3/0x280 net/ipv4/af_inet.c:422 __sock_release net/socket.c:647 [inline] sock_release+0x8e/0x1d0 net/socket.c:675 stop_sync_thread+0x285/0x720 net/netfilter/ipvs/ip_vs_sync.c:2004 do_ip_vs_set_ctl+0x4ec/0x11c0 net/netfilter/ipvs/ip_vs_ctl.c:2734 nf_setsockopt+0x8a/0xf0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424 tcp_setsockopt+0xa4/0x100 net/ipv4/tcp.c:4049 smc_setsockopt+0x1b4/0xa00 net/smc/af_smc.c:3081 do_sock_setsockopt+0x222/0x480 net/socket.c:2303 __sys_setsockopt+0x1a0/0x230 net/socket.c:2328 __do_sys_setsockopt net/socket.c:2334 [inline] __se_sys_setsockopt net/socket.c:2331 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2331 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 RIP: 0033:0x7f363418d169 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:00007f3634f26038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f36343a5fa0 RCX: 00007f363418d169 RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007f363420e2a0 R08: 0000000000000018 R09: 0000000000000000 R10: 00004000000002c0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f36343a5fa0 R15: 00007ffc55f6bbb8