IPVS: stopping backup sync thread 8504 ...
======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc3-syzkaller-00702-gb66e19dcf684 #0 Not tainted
------------------------------------------------------
syz.3.1884/12765 is trying to acquire lock:
ffffffff8fed51c8 (rtnl_mutex){+.+.}-{4:4}, at: ip_mc_drop_socket+0x81/0x280 net/ipv4/igmp.c:2790
but task is already holding lock:
ffff888029bbb8a8 (&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_setsockopt+0x741/0xd10 net/smc/af_smc.c:3104
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]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2331
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:5851
lock_sock_nested+0x48/0x100 net/core/sock.c:3660
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+0x3ab/0xb30 net/core/rtnetlink.c:3802
__rtnl_newlink net/core/rtnetlink.c:3914 [inline]
rtnl_newlink+0x1683/0x1da0 net/core/rtnetlink.c:4029
rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6919
netlink_rcv_skb+0x206/0x480 net/netlink/af_netlink.c:2544
netlink_unicast_kernel net/netlink/af_netlink.c:1323 [inline]
netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1349
netlink_sendmsg+0x8de/0xcb0 net/netlink/af_netlink.c:1893
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_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:2303
__sys_setsockopt net/socket.c:2328 [inline]
__do_sys_setsockopt net/socket.c:2334 [inline]
__se_sys_setsockopt net/socket.c:2331 [inline]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2331
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.3.1884/12765:
#0: ffff888029bbb8a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1c3/0xd10 net/smc/af_smc.c:3073
stack backtrace:
CPU: 1 UID: 0 PID: 12765 Comm: syz.3.1884 Not tainted 6.14.0-rc3-syzkaller-00702-gb66e19dcf684 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__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:2303
__sys_setsockopt net/socket.c:2328 [inline]
__do_sys_setsockopt net/socket.c:2334 [inline]
__se_sys_setsockopt net/socket.c:2331 [inline]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2331
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: 0033:0x7fdc4678d169
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:00007fdc47525038 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fdc469a5fa0 RCX: 00007fdc4678d169
RDX: 000000000000048c RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007fdc4680e2a0 R08: 0000000000000018 R09: 0000000000000000
R10: 00004000000003c0 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fdc469a5fa0 R15: 00007ffd5c70be18
</TASK>