netlink: 24 bytes leftover after parsing attributes in process `syz.7.2114'. ====================================================== WARNING: possible circular locking dependency detected 6.14.0-rc1-syzkaller-00034-g92514ef226f5 #0 Not tainted ------------------------------------------------------ syz.7.2114/12529 is trying to acquire lock: ffff88807da28a18 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1624 [inline] ffff88807da28a18 (sk_lock-AF_INET){+.+.}-{0:0}, at: gtp_encap_enable_socket+0x288/0x4f0 drivers/net/gtp.c:1674 but task is already holding lock: ffffffff8fef67e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] ffffffff8fef67e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] ffffffff8fef67e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x5d9/0x1d60 net/core/rtnetlink.c:4020 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (rtnl_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xb10 kernel/locking/mutex.c:730 start_sync_thread+0x134/0x28e0 net/netfilter/ipvs/ip_vs_sync.c:1761 do_ip_vs_set_ctl+0x452/0x11c0 net/netfilter/ipvs/ip_vs_ctl.c:2732 nf_setsockopt+0x8d/0xf0 net/netfilter/nf_sockopt.c:101 ip_setsockopt+0xcb/0xf0 net/ipv4/ip_sockglue.c:1424 tcp_setsockopt+0xa7/0x100 net/ipv4/tcp.c:4030 smc_setsockopt+0x1b7/0xa00 net/smc/af_smc.c:3081 do_sock_setsockopt+0x225/0x480 net/socket.c:2298 __sys_setsockopt+0x1a0/0x230 net/socket.c:2323 __do_sys_setsockopt net/socket.c:2329 [inline] __se_sys_setsockopt net/socket.c:2326 [inline] __x64_sys_setsockopt+0xbd/0x160 net/socket.c:2326 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 (&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:713 [inline] __sock_sendmsg net/socket.c:728 [inline] __sys_sendto+0x48b/0x4f0 net/socket.c:2182 __do_sys_sendto net/socket.c:2189 [inline] __se_sys_sendto net/socket.c:2185 [inline] __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2185 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 (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 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 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:1718 [inline] gtp_newlink+0xf03/0x12f0 drivers/net/gtp.c:1511 rtnl_newlink_create net/core/rtnetlink.c:3795 [inline] __rtnl_newlink net/core/rtnetlink.c:3906 [inline] rtnl_newlink+0xb98/0x1d60 net/core/rtnetlink.c:4021 rtnetlink_rcv_msg+0x95e/0xea0 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x16e/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x53f/0x7f0 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0xab2/0xc90 net/socket.c:2568 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2622 __sys_sendmsg+0x16e/0x220 net/socket.c:2654 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: 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.7.2114/12529: #0: ffffffff90629200 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:164 [inline] #0: ffffffff90629200 (&ops->srcu#2){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:256 [inline] #0: ffffffff90629200 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x10f/0x2c0 net/core/rtnetlink.c:568 #1: ffffffff8fef67e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:79 [inline] #1: ffffffff8fef67e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:335 [inline] #1: ffffffff8fef67e8 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x5d9/0x1d60 net/core/rtnetlink.c:4020 stack backtrace: CPU: 0 UID: 0 PID: 12529 Comm: syz.7.2114 Not tainted 6.14.0-rc1-syzkaller-00034-g92514ef226f5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 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 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:1718 [inline] gtp_newlink+0xf03/0x12f0 drivers/net/gtp.c:1511 rtnl_newlink_create net/core/rtnetlink.c:3795 [inline] __rtnl_newlink net/core/rtnetlink.c:3906 [inline] rtnl_newlink+0xb98/0x1d60 net/core/rtnetlink.c:4021 rtnetlink_rcv_msg+0x95e/0xea0 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x16e/0x440 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x53f/0x7f0 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0xab2/0xc90 net/socket.c:2568 ___sys_sendmsg+0x135/0x1e0 net/socket.c:2622 __sys_sendmsg+0x16e/0x220 net/socket.c:2654 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: 0033:0x7f616f78cde9 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:00007f61706bc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f616f9a5fa0 RCX: 00007f616f78cde9 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000004 RBP: 00007f616f80e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f616f9a5fa0 R15: 00007ffed67a50d8