====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc5-syzkaller-00105-gf315296c92fd #0 Not tainted ------------------------------------------------------ syz.3.765/8016 is trying to acquire lock: ffff8880621cf698 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1624 [inline] ffff8880621cf698 (sk_lock-AF_INET){+.+.}-{0:0}, at: gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674 but task is already holding lock: ffffffff8fed5a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] ffffffff8fed5a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] ffffffff8fed5a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc55/0x1d30 net/core/rtnetlink.c:4021 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (rtnl_mutex){+.+.}-{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 start_sync_thread+0xdc/0x2d30 net/netfilter/ipvs/ip_vs_sync.c:1761 do_ip_vs_set_ctl+0x495/0xe40 net/netfilter/ipvs/ip_vs_ctl.c:2732 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:2303 __sys_setsockopt net/socket.c:2328 [inline] __do_sys_setsockopt net/socket.c:2334 [inline] __se_sys_setsockopt net/socket.c:2331 [inline] __ia32_sys_setsockopt+0x1f2/0x280 net/socket.c:2331 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:387 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:412 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #1 (&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:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 __sys_sendto+0x363/0x4c0 net/socket.c:2187 __do_sys_sendto net/socket.c:2194 [inline] __se_sys_sendto net/socket.c:2190 [inline] __ia32_sys_sendto+0xdd/0x100 net/socket.c:2190 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:387 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:412 entry_SYSENTER_compat_after_hwframe+0x84/0x8e -> #0 (sk_lock-AF_INET){+.+.}-{0:0}: 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 lock_sock_nested+0x48/0x100 net/core/sock.c:3662 lock_sock include/net/sock.h:1624 [inline] gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674 gtp_encap_enable drivers/net/gtp.c:1708 [inline] gtp_newlink+0x5a7/0xf20 drivers/net/gtp.c:1511 rtnl_newlink_create+0x2ee/0xa40 net/core/rtnetlink.c:3796 __rtnl_newlink net/core/rtnetlink.c:3907 [inline] rtnl_newlink+0x17cc/0x1d30 net/core/rtnetlink.c:4022 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6912 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2533 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1882 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 ____sys_sendmsg+0x53a/0x860 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2659 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:387 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:412 entry_SYSENTER_compat_after_hwframe+0x84/0x8e other info that might help us debug this: Chain exists of: sk_lock-AF_INET --> &smc->clcsock_release_lock --> rtnl_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(rtnl_mutex); lock(&smc->clcsock_release_lock); lock(rtnl_mutex); lock(sk_lock-AF_INET); *** DEADLOCK *** 2 locks held by syz.3.765/8016: #0: ffffffff903d3ab0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff903d3ab0 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff903d3ab0 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x22/0x250 net/core/rtnetlink.c:564 #1: ffffffff8fed5a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fed5a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] #1: ffffffff8fed5a08 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0xc55/0x1d30 net/core/rtnetlink.c:4021 stack backtrace: CPU: 1 UID: 0 PID: 8016 Comm: syz.3.765 Not tainted 6.14.0-rc5-syzkaller-00105-gf315296c92fd #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 lock_sock_nested+0x48/0x100 net/core/sock.c:3662 lock_sock include/net/sock.h:1624 [inline] gtp_encap_enable_socket+0x2ce/0x5c0 drivers/net/gtp.c:1674 gtp_encap_enable drivers/net/gtp.c:1708 [inline] gtp_newlink+0x5a7/0xf20 drivers/net/gtp.c:1511 rtnl_newlink_create+0x2ee/0xa40 net/core/rtnetlink.c:3796 __rtnl_newlink net/core/rtnetlink.c:3907 [inline] rtnl_newlink+0x17cc/0x1d30 net/core/rtnetlink.c:4022 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6912 netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2533 netlink_unicast_kernel net/netlink/af_netlink.c:1312 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1338 netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1882 sock_sendmsg_nosec net/socket.c:718 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:733 ____sys_sendmsg+0x53a/0x860 net/socket.c:2573 ___sys_sendmsg net/socket.c:2627 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2659 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline] __do_fast_syscall_32+0xb4/0x110 arch/x86/entry/common.c:387 do_fast_syscall_32+0x34/0x80 arch/x86/entry/common.c:412 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f57579 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:00000000f507655c EFLAGS: 00000206 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000080000080 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 gtp0: entered promiscuous mode gtp0: entered allmulticast mode ---------------- 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