[v6.6] inconsistent lock state in valid_state (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: aa0e49877a2e Linux 6.6.148
git tree: linux-6.6.y
console output: https://syzkaller.appspot.com/x/log.txt?x=10d5f649580000
kernel config: https://syzkaller.appspot.com/x/.config?x=f0bc3d90c30838b5
dashboard link: https://syzkaller.appspot.com/bug?extid=4358593ed3ab3b8a104b
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/f83b390cfc1f/disk-aa0e4987.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/1d4bdb338edd/vmlinux-aa0e4987.xz
kernel image: https://storage.googleapis.com/syzbot-assets/3f57c1d51ee3/bzImage-aa0e4987.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+435859...@syzkaller.appspotmail.com

================================
WARNING: inconsistent lock state
syzkaller #0 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/1/22 [HC0[0]:SC1[1]:HE1:SE0] takes:
ffff88802f0d2130 (sk_lock-AF_X25){+.?.}-{0:0}, at: lock_sock include/net/sock.h:1780 [inline]
ffff88802f0d2130 (sk_lock-AF_X25){+.?.}-{0:0}, at: x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782
{SOFTIRQ-ON-W} state was registered at:
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
lock_sock_nested+0x48/0x100 net/core/sock.c:3544
lock_sock include/net/sock.h:1780 [inline]
x25_bind+0x20a/0x460 net/x25/af_x25.c:698
__sys_bind+0x2f0/0x3f0 net/socket.c:1856
__do_sys_bind net/socket.c:1867 [inline]
__se_sys_bind net/socket.c:1865 [inline]
__x64_sys_bind+0x7a/0x90 net/socket.c:1865
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
irq event stamp: 4240832
hardirqs last enabled at (4240832): [<ffffffff8152ccba>] __local_bh_enable_ip+0x13a/0x1c0 kernel/softirq.c:411
hardirqs last disabled at (4240831): [<ffffffff8152cc5b>] __local_bh_enable_ip+0xdb/0x1c0 kernel/softirq.c:388
softirqs last enabled at (4240696): [<ffffffff8152f928>] run_ksoftirqd+0xa8/0x100 kernel/softirq.c:950
softirqs last disabled at (4240701): [<ffffffff8152f928>] run_ksoftirqd+0xa8/0x100 kernel/softirq.c:950

other info that might help us debug this:
Possible unsafe locking scenario:

CPU0
----
lock(sk_lock-AF_X25);
<Interrupt>
lock(sk_lock-AF_X25);

*** DEADLOCK ***

1 lock held by ksoftirqd/1/22:
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:334 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:786 [inline]
#0: ffffffff8d131da0 (rcu_read_lock){....}-{1:2}, at: netif_receive_skb_core+0x34/0x230 net/core/dev.c:5670

stack backtrace:
CPU: 1 PID: 22 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
valid_state+0x13b/0x1d0 kernel/locking/lockdep.c:4013
mark_lock_irq+0xad/0x900 kernel/locking/lockdep.c:4216
mark_lock+0x208/0x320 kernel/locking/lockdep.c:4678
mark_usage kernel/locking/lockdep.c:-1 [inline]
__lock_acquire+0xcfc/0x7d80 kernel/locking/lockdep.c:5091
lock_acquire+0x19e/0x420 kernel/locking/lockdep.c:5754
lock_sock_nested+0x48/0x100 net/core/sock.c:3544
lock_sock include/net/sock.h:1780 [inline]
x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782
x25_lapb_receive_frame+0x1a7/0xef0 net/x25/x25_dev.c:138
__netif_receive_skb_one_core net/core/dev.c:5646 [inline]
netif_receive_skb_core+0x16a/0x230 net/core/dev.c:5671
lapbeth_napi_poll+0x42/0x80 drivers/net/wan/lapbether.c:99
__napi_poll+0xbb/0x460 net/core/dev.c:6650
napi_poll net/core/dev.c:6717 [inline]
net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
run_ksoftirqd+0xa8/0x100 kernel/softirq.c:950
smpboot_thread_fn+0x651/0x9f0 kernel/smpboot.c:164
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
BUG: sleeping function called from invalid context at net/core/sock.c:3546
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 22, name: ksoftirqd/1
preempt_count: 100, expected: 0
RCU nest depth: 1, expected: 0
INFO: lockdep is turned off.
Preemption disabled at:
[<ffffffff8152cfe1>] softirq_handle_begin kernel/softirq.c:419 [inline]
[<ffffffff8152cfe1>] handle_softirqs+0x101/0x820 kernel/softirq.c:554
CPU: 1 PID: 22 Comm: ksoftirqd/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
<TASK>
dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106
__might_resched+0x48d/0x5f0 kernel/sched/core.c:10212
lock_sock_nested+0x5d/0x100 net/core/sock.c:3546
lock_sock include/net/sock.h:1780 [inline]
x25_kill_by_neigh+0x10d/0x250 net/x25/af_x25.c:1782
x25_lapb_receive_frame+0x1a7/0xef0 net/x25/x25_dev.c:138
__netif_receive_skb_one_core net/core/dev.c:5646 [inline]
netif_receive_skb_core+0x16a/0x230 net/core/dev.c:5671
lapbeth_napi_poll+0x42/0x80 drivers/net/wan/lapbether.c:99
__napi_poll+0xbb/0x460 net/core/dev.c:6650
napi_poll net/core/dev.c:6717 [inline]
net_rx_action+0x65f/0xcc0 net/core/dev.c:6853
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
run_ksoftirqd+0xa8/0x100 kernel/softirq.c:950
smpboot_thread_fn+0x651/0x9f0 kernel/smpboot.c:164
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>


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