XFS (loop4): Ending clean mount
XFS (loop4): Quotacheck needed: Please wait.
XFS (loop4): Quotacheck: Done.
======================================================
WARNING: possible circular locking dependency detected
5.15.178-syzkaller #0 Not tainted
------------------------------------------------------
syz.4.496/6518 is trying to acquire lock:
ffffffff8dd7dbb8 (nr_neigh_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffffffff8dd7dbb8 (nr_neigh_list_lock){+...}-{2:2}, at: nr_remove_neigh net/netrom/nr_route.c:307 [inline]
ffffffff8dd7dbb8 (nr_neigh_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:472 [inline]
ffffffff8dd7dbb8 (nr_neigh_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0x394/0x1880 net/netrom/nr_route.c:692
but task is already holding lock:
ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: nr_node_lock include/net/netrom.h:151 [inline]
ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:459 [inline]
ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: nr_rt_ioctl+0x18e/0x1880 net/netrom/nr_route.c:692
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&nr_node->node_lock){+...}-{2:2}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:368 [inline]
nr_node_lock include/net/netrom.h:151 [inline]
nr_rt_device_down+0x155/0x7b0 net/netrom/nr_route.c:519
nr_device_event+0x12b/0x140 net/netrom/af_netrom.c:126
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
__dev_notify_flags+0x304/0x610
dev_change_flags+0xe7/0x190 net/core/dev.c:8897
dev_ifsioc+0x147/0x10c0 net/core/dev_ioctl.c:324
dev_ioctl+0x504/0xf60 net/core/dev_ioctl.c:587
sock_do_ioctl+0x34f/0x5a0 net/socket.c:1154
sock_ioctl+0x47f/0x770 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #1 (nr_node_list_lock){+...}-{2:2}:
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:368 [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:83 [inline]
raw_notifier_call_chain+0xd0/0x170 kernel/notifier.c:391
__dev_notify_flags+0x304/0x610
dev_change_flags+0xe7/0x190 net/core/dev.c:8897
dev_ifsioc+0x147/0x10c0 net/core/dev_ioctl.c:324
dev_ioctl+0x504/0xf60 net/core/dev_ioctl.c:587
sock_do_ioctl+0x34f/0x5a0 net/socket.c:1154
sock_ioctl+0x47f/0x770 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
-> #0 (nr_neigh_list_lock){+...}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:368 [inline]
nr_remove_neigh net/netrom/nr_route.c:307 [inline]
nr_dec_obs net/netrom/nr_route.c:472 [inline]
nr_rt_ioctl+0x394/0x1880 net/netrom/nr_route.c:692
sock_do_ioctl+0x11d/0x5a0 net/socket.c:1140
sock_ioctl+0x47f/0x770 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
other info that might help us debug this:
Chain exists of:
nr_neigh_list_lock --> nr_node_list_lock --> &nr_node->node_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&nr_node->node_lock);
lock(nr_node_list_lock);
lock(&nr_node->node_lock);
lock(nr_neigh_list_lock);
*** DEADLOCK ***
2 locks held by syz.4.496/6518:
#0: ffffffff8dd7dc18 (nr_node_list_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
#0: ffffffff8dd7dc18 (nr_node_list_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:457 [inline]
#0: ffffffff8dd7dc18 (nr_node_list_lock){+...}-{2:2}, at: nr_rt_ioctl+0xfc/0x1880 net/netrom/nr_route.c:692
#1: ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: spin_lock_bh include/linux/spinlock.h:368 [inline]
#1: ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: nr_node_lock include/net/netrom.h:151 [inline]
#1: ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: nr_dec_obs net/netrom/nr_route.c:459 [inline]
#1: ffff8880232a8770 (&nr_node->node_lock){+...}-{2:2}, at: nr_rt_ioctl+0x18e/0x1880 net/netrom/nr_route.c:692
stack backtrace:
CPU: 1 PID: 6518 Comm: syz.4.496 Not tainted 5.15.178-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
check_noncircular+0x2f8/0x3b0 kernel/locking/lockdep.c:2133
check_prev_add kernel/locking/lockdep.c:3053 [inline]
check_prevs_add kernel/locking/lockdep.c:3172 [inline]
validate_chain+0x1649/0x5930 kernel/locking/lockdep.c:3788
__lock_acquire+0x1295/0x1ff0 kernel/locking/lockdep.c:5012
lock_acquire+0x1db/0x4f0 kernel/locking/lockdep.c:5623
__raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
_raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:178
spin_lock_bh include/linux/spinlock.h:368 [inline]
nr_remove_neigh net/netrom/nr_route.c:307 [inline]
nr_dec_obs net/netrom/nr_route.c:472 [inline]
nr_rt_ioctl+0x394/0x1880 net/netrom/nr_route.c:692
sock_do_ioctl+0x11d/0x5a0 net/socket.c:1140
sock_ioctl+0x47f/0x770 net/socket.c:1257
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f4a73e8e169
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:00007f4a71cf7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f4a740a6fa0 RCX: 00007f4a73e8e169
RDX: 0000000000000000 RSI: 00000000000089e2 RDI: 0000000000000008
RBP: 00007f4a73f0f2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f4a740a6fa0 R15: 00007ffe62ddeca8
</TASK>