======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc2-syzkaller-00087-gcfb2e2c57aef #0 Not tainted
------------------------------------------------------
syz.6.848/9083 is trying to acquire lock:
ffff888036118aa8 (&smc->clcsock_release_lock){+.+.}-{4:4}, at: smc_switch_to_fallback+0x35/0xda0 net/smc/af_smc.c:903
but task is already holding lock:
ffff888036118258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline]
ffff888036118258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: smc_sendmsg+0x55/0x530 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_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]
__x64_sys_setsockopt+0x1ee/0x280 net/socket.c:2324
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (rtnl_mutex){+.+.}-{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
do_ip_getsockopt+0x11ae/0x2ba0 net/ipv4/ip_sockglue.c:1702
ip_getsockopt+0xef/0x2e0 net/ipv4/ip_sockglue.c:1765
tcp_getsockopt+0x16f/0x1d0 net/ipv4/tcp.c:4727
smc_getsockopt+0x1c6/0x400 net/smc/af_smc.c:3163
do_sock_getsockopt+0x391/0x740 net/socket.c:2357
__sys_getsockopt net/socket.c:2386 [inline]
__do_sys_getsockopt net/socket.c:2393 [inline]
__se_sys_getsockopt net/socket.c:2390 [inline]
__x64_sys_getsockopt+0x2a3/0x370 net/socket.c:2390
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 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+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
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]
__x64_sys_sendto+0xde/0x100 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 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_INET6
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_INET6);
lock(rtnl_mutex);
lock(sk_lock-AF_INET6);
lock(&smc->clcsock_release_lock);
*** DEADLOCK ***
1 lock held by syz.6.848/9083:
#0: ffff888036118258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline]
#0: ffff888036118258 (sk_lock-AF_INET6){+.+.}-{0:0}, at: smc_sendmsg+0x55/0x530 net/smc/af_smc.c:2775
stack backtrace:
CPU: 1 UID: 0 PID: 9083 Comm: syz.6.848 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
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]
__x64_sys_sendto+0xde/0x100 net/socket.c:2183
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3a0318e169
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:00007f3a040cc038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f3a033b5fa0 RCX: 00007f3a0318e169
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000c
RBP: 00007f3a03210a68 R08: 0000200000000100 R09: 000000000000001c
R10: fffffefffbfbbfbe R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f3a033b5fa0 R15: 00007f3a034dfa28
</TASK>