======================================================
WARNING: possible circular locking dependency detected
6.1.126-syzkaller #0 Not tainted
------------------------------------------------------
syz.3.920/7489 is trying to acquire lock:
ffffffff8e6538d8 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffffffff8e6538d8 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_device_down+0xb1/0x7b0 net/netrom/nr_route.c:517
but task is already holding lock:
ffffffff8e653878 (nr_neigh_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
ffffffff8e653878 (nr_neigh_list_lock){+...}-{2:2}, at: nr_rt_device_down+0x24/0x7b0 net/netrom/nr_route.c:514
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (nr_neigh_list_lock){+...}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
nr_remove_neigh net/netrom/nr_route.c:307 [inline]
nr_dec_obs net/netrom/nr_route.c:472 [inline]
nr_rt_ioctl+0x394/0xfb0 net/netrom/nr_route.c:692
sock_do_ioctl+0x152/0x450 net/socket.c:1204
sock_ioctl+0x47f/0x770 net/socket.c:1321
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #1 (&nr_node->node_lock){+...}-{2:2}:
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
nr_node_lock include/net/netrom.h:152 [inline]
nr_dec_obs net/netrom/nr_route.c:459 [inline]
nr_rt_ioctl+0x18e/0xfb0 net/netrom/nr_route.c:692
sock_do_ioctl+0x152/0x450 net/socket.c:1204
sock_ioctl+0x47f/0x770 net/socket.c:1321
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
-> #0 (nr_node_list_lock){+...}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
nr_rt_device_down+0xb1/0x7b0 net/netrom/nr_route.c:517
nr_device_event+0x12b/0x140 net/netrom/af_netrom.c:126
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455
call_netdevice_notifiers_info net/core/dev.c:1970 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2008 [inline]
call_netdevice_notifiers net/core/dev.c:2022 [inline]
dev_close_many+0x37c/0x530 net/core/dev.c:1570
dev_close+0x1b3/0x2b0 net/core/dev.c:1592
bpq_device_event+0x35f/0x8a0 drivers/net/hamradio/bpqether.c:547
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455
__dev_notify_flags+0x304/0x610
dev_change_flags+0xe7/0x190 net/core/dev.c:8671
dev_ifsioc+0x177/0x1160 net/core/dev_ioctl.c:327
dev_ioctl+0x508/0xf70 net/core/dev_ioctl.c:588
sock_do_ioctl+0x26b/0x450 net/socket.c:1218
sock_ioctl+0x47f/0x770 net/socket.c:1321
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
other info that might help us debug this:
Chain exists of:
nr_node_list_lock --> &nr_node->node_lock --> nr_neigh_list_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(nr_neigh_list_lock);
lock(&nr_node->node_lock);
lock(nr_neigh_list_lock);
lock(nr_node_list_lock);
*** DEADLOCK ***
2 locks held by syz.3.920/7489:
#0: ffffffff8e50b968 (rtnl_mutex){+.+.}-{3:3}, at: dev_ioctl+0x4f5/0xf70 net/core/dev_ioctl.c:587
#1: ffffffff8e653878 (nr_neigh_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:356 [inline]
#1: ffffffff8e653878 (nr_neigh_list_lock){+...}-{2:2}, at: nr_rt_device_down+0x24/0x7b0 net/netrom/nr_route.c:514
stack backtrace:
CPU: 0 PID: 7489 Comm: syz.3.920 Not tainted 6.1.126-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
check_prev_add kernel/locking/lockdep.c:3090 [inline]
check_prevs_add kernel/locking/lockdep.c:3209 [inline]
validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
__lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:126 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:356 [inline]
nr_rt_device_down+0xb1/0x7b0 net/netrom/nr_route.c:517
nr_device_event+0x12b/0x140 net/netrom/af_netrom.c:126
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455
call_netdevice_notifiers_info net/core/dev.c:1970 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2008 [inline]
call_netdevice_notifiers net/core/dev.c:2022 [inline]
dev_close_many+0x37c/0x530 net/core/dev.c:1570
dev_close+0x1b3/0x2b0 net/core/dev.c:1592
bpq_device_event+0x35f/0x8a0 drivers/net/hamradio/bpqether.c:547
notifier_call_chain kernel/notifier.c:87 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:455
__dev_notify_flags+0x304/0x610
dev_change_flags+0xe7/0x190 net/core/dev.c:8671
dev_ifsioc+0x177/0x1160 net/core/dev_ioctl.c:327
dev_ioctl+0x508/0xf70 net/core/dev_ioctl.c:588
sock_do_ioctl+0x26b/0x450 net/socket.c:1218
sock_ioctl+0x47f/0x770 net/socket.c:1321
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5dfd785d29
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:00007f5dfe4ef038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5dfd975fa0 RCX: 00007f5dfd785d29
RDX: 0000000020000700 RSI: 0000000000008914 RDI: 0000000000000008
RBP: 00007f5dfd801b08 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5dfd975fa0 R15: 00007ffec29bd7f8
</TASK>