======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc2-syzkaller-00087-gcfb2e2c57aef #0 Not tainted
------------------------------------------------------
syz.0.3018/18737 is trying to acquire lock:
ffff88807afd8aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_switch_to_fallback+0x2d/0x9f0 net/smc/af_smc.c:903
but task is already holding lock:
ffff88807afd8258 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline]
ffff88807afd8258 (sk_lock-AF_INET){+.+.}-{0:0}, at: smc_sendmsg+0x47/0x520 net/smc/af_smc.c:2775
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (sk_lock-AF_INET){+.+.}-{0:0}:
lock_sock_nested+0x41/0xf0 net/core/sock.c:3702
lock_sock include/net/sock.h:1651 [inline]
sockopt_lock_sock net/core/sock.c:1148 [inline]
sockopt_lock_sock+0x54/0x70 net/core/sock.c:1139
do_ip_setsockopt+0xfe/0x3240 net/ipv4/ip_sockglue.c:1078
ip_setsockopt+0x59/0xf0 net/ipv4/ip_sockglue.c:1417
udp_setsockopt+0x7d/0xd0 net/ipv4/udp.c:3058
do_sock_setsockopt+0x221/0x470 net/socket.c:2296
__sys_setsockopt+0x1a0/0x230 net/socket.c:2321
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__x64_sys_setsockopt+0xbd/0x160 net/socket.c:2324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (rtnl_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
start_sync_thread+0x120/0x28b0 net/netfilter/ipvs/ip_vs_sync.c:1761
do_ip_vs_set_ctl+0x451/0x11d0 net/netfilter/ipvs/ip_vs_ctl.c:2732
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:4077
smc_setsockopt+0x1b3/0xa00 net/smc/af_smc.c:3081
do_sock_setsockopt+0x221/0x470 net/socket.c:2296
__sys_setsockopt+0x1a0/0x230 net/socket.c:2321
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__x64_sys_setsockopt+0xbd/0x160 net/socket.c:2324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&smc->clcsock_release_lock){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain kernel/locking/lockdep.c:3909 [inline]
__lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235
lock_acquire kernel/locking/lockdep.c:5866 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
smc_switch_to_fallback+0x2d/0x9f0 net/smc/af_smc.c:903
smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
__sys_sendto+0x495/0x510 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&smc->clcsock_release_lock --> rtnl_mutex --> sk_lock-AF_INET
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_INET);
lock(rtnl_mutex);
lock(sk_lock-AF_INET);
lock(&smc->clcsock_release_lock);
*** DEADLOCK ***
1 lock held by syz.0.3018/18737:
#0: ffff88807afd8258 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline]
#0: ffff88807afd8258 (sk_lock-AF_INET){+.+.}-{0:0}, at: smc_sendmsg+0x47/0x520 net/smc/af_smc.c:2775
stack backtrace:
CPU: 1 UID: 0 PID: 18737 Comm: syz.0.3018 Not tainted 6.15.0-rc2-syzkaller-00087-gcfb2e2c57aef #0 PREEMPT(full)
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+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x275/0x350 kernel/locking/lockdep.c:2079
check_noncircular+0x14c/0x170 kernel/locking/lockdep.c:2211
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain kernel/locking/lockdep.c:3909 [inline]
__lock_acquire+0x1173/0x1ba0 kernel/locking/lockdep.c:5235
lock_acquire kernel/locking/lockdep.c:5866 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x199/0xb90 kernel/locking/mutex.c:746
smc_switch_to_fallback+0x2d/0x9f0 net/smc/af_smc.c:903
smc_sendmsg+0x13d/0x520 net/smc/af_smc.c:2781
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg net/socket.c:727 [inline]
__sys_sendto+0x495/0x510 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f36bd98e169
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:00007f36bb7d5038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f36bdbb6160 RCX: 00007f36bd98e169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: 00007f36bda10a68 R08: 0000200000e68000 R09: 0000000000000010
R10: 00000000200007fd R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f36bdbb6160 R15: 00007fff7c84b038
</TASK>
IPVS: Schedule: port zero only supported in persistent services, check your ipvs configuration