======================================================
WARNING: possible circular locking dependency detected
6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #0 Tainted: G U
------------------------------------------------------
kworker/1:5/5896 is trying to acquire lock:
ffffffff9012e6e8 (rtnl_mutex){+.+.}-{4:4}, at: smc_vlan_by_tcpsk+0x251/0x620 net/smc/smc_core.c:1908
but task is already holding lock:
ffff888057405e58 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline]
ffff888057405e58 (sk_lock-AF_INET){+.+.}-{0:0}, at: smc_connect_work+0x53a/0xae0 net/smc/af_smc.c:1600
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (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_getsockopt+0x13e4/0x2220 net/ipv4/ip_sockglue.c:1703
ip_getsockopt+0x9b/0x1e0 net/ipv4/ip_sockglue.c:1765
raw_getsockopt+0x4d/0x1f0 net/ipv4/raw.c:865
do_sock_getsockopt+0x3fc/0x800 net/socket.c:2357
__sys_getsockopt+0x12f/0x260 net/socket.c:2386
__do_sys_getsockopt net/socket.c:2393 [inline]
__se_sys_getsockopt net/socket.c:2390 [inline]
__x64_sys_getsockopt+0xbd/0x160 net/socket.c:2390
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 (rtnl_mutex){+.+.}-{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_vlan_by_tcpsk+0x251/0x620 net/smc/smc_core.c:1908
__smc_connect+0x44b/0x4880 net/smc/af_smc.c:1520
smc_connect_work+0x54c/0xae0 net/smc/af_smc.c:1613
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(sk_lock-AF_INET);
lock(rtnl_mutex);
lock(sk_lock-AF_INET);
lock(rtnl_mutex);
*** DEADLOCK ***
3 locks held by kworker/1:5/5896:
#0: ffff88803138ad48 ((wq_completion)smc_hs_wq){+.+.}-{0:0}, at: process_one_work+0x12a2/0x1b70 kernel/workqueue.c:3213
#1: ffffc9000452fd18 ((work_completion)(&smc->connect_work)){+.+.}-{0:0}, at: process_one_work+0x929/0x1b70 kernel/workqueue.c:3214
#2: ffff888057405e58 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1651 [inline]
#2: ffff888057405e58 (sk_lock-AF_INET){+.+.}-{0:0}, at: smc_connect_work+0x53a/0xae0 net/smc/af_smc.c:1600
stack backtrace:
CPU: 1 UID: 0 PID: 5896 Comm: kworker/1:5 Tainted: G U 6.15.0-rc2-syzkaller-00048-gc62f4b82d571 #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: smc_hs_wq smc_connect_work
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_vlan_by_tcpsk+0x251/0x620 net/smc/smc_core.c:1908
__smc_connect+0x44b/0x4880 net/smc/af_smc.c:1520
smc_connect_work+0x54c/0xae0 net/smc/af_smc.c:1613
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
</TASK>