IPVS: stopping backup sync thread 10186 ... ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc7-syzkaller-01431-gbfc17c165835 #0 Not tainted ------------------------------------------------------ syz.5.2910/16566 is trying to acquire lock: ffffffff8fed7108 (rtnl_mutex){+.+.}-{4:4}, at: ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790 but task is already holding lock: ffff88805b0da1a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1c3/0xd10 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}: lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 smc_switch_to_fallback+0x35/0xd90 net/smc/af_smc.c:903 smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2781 sock_sendmsg_nosec net/socket.c:709 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:724 __sys_sendto+0x363/0x4c0 net/socket.c:2178 __do_sys_sendto net/socket.c:2185 [inline] __se_sys_sendto net/socket.c:2181 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2181 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:5851 lock_sock_nested+0x48/0x100 net/core/sock.c:3697 lock_sock include/net/sock.h:1615 [inline] gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1676 gtp_encap_enable drivers/net/gtp.c:1710 [inline] gtp_newlink+0x5ff/0xf70 drivers/net/gtp.c:1513 rtnl_newlink_create+0x37b/0xbd0 net/core/rtnetlink.c:3830 __rtnl_newlink net/core/rtnetlink.c:3947 [inline] rtnl_newlink+0x167a/0x1d90 net/core/rtnetlink.c:4062 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6952 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:709 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:724 ____sys_sendmsg+0x53a/0x860 net/socket.c:2564 ___sys_sendmsg net/socket.c:2618 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2650 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:3163 [inline] check_prevs_add kernel/locking/lockdep.c:3282 [inline] validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790 inet_release+0x96/0x200 net/ipv4/af_inet.c:422 __sock_release net/socket.c:647 [inline] sock_release+0x82/0x150 net/socket.c:675 stop_sync_thread+0x4e6/0x5e0 net/netfilter/ipvs/ip_vs_sync.c:2004 do_ip_vs_set_ctl+0x4c8/0xe40 net/netfilter/ipvs/ip_vs_ctl.c:2734 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 smc_setsockopt+0x275/0xd10 net/smc/af_smc.c:3081 do_sock_setsockopt+0x3af/0x720 net/socket.c:2294 __sys_setsockopt net/socket.c:2319 [inline] __do_sys_setsockopt net/socket.c:2325 [inline] __se_sys_setsockopt net/socket.c:2322 [inline] __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2322 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.5.2910/16566: #0: ffff88805b0da1a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1c3/0xd10 net/smc/af_smc.c:3073 stack backtrace: CPU: 0 UID: 0 PID: 16566 Comm: syz.5.2910 Not tainted 6.14.0-rc7-syzkaller-01431-gbfc17c165835 #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+0x241/0x360 lib/dump_stack.c:120 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2076 check_noncircular+0x36a/0x4a0 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+0x18ef/0x5920 kernel/locking/lockdep.c:3906 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851 __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19c/0x1010 kernel/locking/mutex.c:730 ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790 inet_release+0x96/0x200 net/ipv4/af_inet.c:422 __sock_release net/socket.c:647 [inline] sock_release+0x82/0x150 net/socket.c:675 stop_sync_thread+0x4e6/0x5e0 net/netfilter/ipvs/ip_vs_sync.c:2004 do_ip_vs_set_ctl+0x4c8/0xe40 net/netfilter/ipvs/ip_vs_ctl.c:2734 nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101 smc_setsockopt+0x275/0xd10 net/smc/af_smc.c:3081 do_sock_setsockopt+0x3af/0x720 net/socket.c:2294 __sys_setsockopt net/socket.c:2319 [inline] __do_sys_setsockopt net/socket.c:2325 [inline] __se_sys_setsockopt net/socket.c:2322 [inline] __x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2322 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: 0033:0x7f49ebf8d169 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:00007f49ecda8038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 00007f49ec1a5fa0 RCX: 00007f49ebf8d169 RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000007 RBP: 00007f49ec00e2a0 R08: 0000000000000018 R09: 0000000000000000 R10: 00002000000003c0 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f49ec1a5fa0 R15: 00007ffd24033618