======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc2-syzkaller-00087-gcfb2e2c57aef #0 Not tainted
------------------------------------------------------
syz.4.5275/27810 is trying to acquire lock:
ffffffff900fd5c8 (rtnl_mutex){+.+.}-{4:4}, at: start_sync_thread+0xde/0x2d60 net/netfilter/ipvs/ip_vs_sync.c:1761
but task is already holding lock:
ffff8880321138a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1b2/0xd50 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+0x116/0x2f0 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
smc_switch_to_fallback+0x35/0xda0 net/smc/af_smc.c:903
smc_sendmsg+0x11f/0x530 net/smc/af_smc.c:2781
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x221/0x270 net/socket.c:727
__sys_sendto+0x365/0x4c0 net/socket.c:2180
__do_sys_sendto net/socket.c:2187 [inline]
__se_sys_sendto net/socket.c:2183 [inline]
__ia32_sys_sendto+0xdd/0x100 net/socket.c:2183
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #1 (sk_lock-AF_INET6){+.+.}-{0:0}:
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
lock_sock_nested+0x48/0x100 net/core/sock.c:3702
do_ipv6_setsockopt+0xccd/0x3680 net/ipv6/ipv6_sockglue.c:567
ipv6_setsockopt+0x5d/0x170 net/ipv6/ipv6_sockglue.c:993
do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296
__sys_setsockopt net/socket.c:2321 [inline]
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__ia32_sys_setsockopt+0x1f2/0x280 net/socket.c:2324
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
-> #0 (rtnl_mutex){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3166 [inline]
check_prevs_add kernel/locking/lockdep.c:3285 [inline]
validate_chain+0xa69/0x24e0 kernel/locking/lockdep.c:3909
__lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
start_sync_thread+0xde/0x2d60 net/netfilter/ipvs/ip_vs_sync.c:1761
do_ip_vs_set_ctl+0x48e/0xe50 net/netfilter/ipvs/ip_vs_ctl.c:2732
nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
smc_setsockopt+0x25c/0xd50 net/smc/af_smc.c:3081
do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296
__sys_setsockopt net/socket.c:2321 [inline]
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__ia32_sys_setsockopt+0x1f2/0x280 net/socket.c:2324
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
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.4.5275/27810:
#0: ffff8880321138a8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_setsockopt+0x1b2/0xd50 net/smc/af_smc.c:3073
stack backtrace:
CPU: 0 UID: 0 PID: 27810 Comm: syz.4.5275 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+0x241/0x360 lib/dump_stack.c:120
print_circular_bug+0x2e1/0x300 kernel/locking/lockdep.c:2079
check_noncircular+0x142/0x160 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+0xa69/0x24e0 kernel/locking/lockdep.c:3909
__lock_acquire+0xad5/0xd80 kernel/locking/lockdep.c:5235
lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x1a5/0x10c0 kernel/locking/mutex.c:746
start_sync_thread+0xde/0x2d60 net/netfilter/ipvs/ip_vs_sync.c:1761
do_ip_vs_set_ctl+0x48e/0xe50 net/netfilter/ipvs/ip_vs_ctl.c:2732
nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
smc_setsockopt+0x25c/0xd50 net/smc/af_smc.c:3081
do_sock_setsockopt+0x3b1/0x710 net/socket.c:2296
__sys_setsockopt net/socket.c:2321 [inline]
__do_sys_setsockopt net/socket.c:2327 [inline]
__se_sys_setsockopt net/socket.c:2324 [inline]
__ia32_sys_setsockopt+0x1f2/0x280 net/socket.c:2324
do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
__do_fast_syscall_32+0xb4/0x110 arch/x86/entry/syscall_32.c:306
do_fast_syscall_32+0x34/0x80 arch/x86/entry/syscall_32.c:331
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fd5579
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:00000000f50f655c EFLAGS: 00000206 ORIG_RAX: 000000000000016e
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000000000
RDX: 000000000000048b RSI: 0000000080000040 RDI: 0000000000000018
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
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