hamradio: ignore ops-locked netdevs
authorStanislav Fomichev <sdf@fomichev.me>
Wed, 6 Aug 2025 21:37:26 +0000 (14:37 -0700)
committerJakub Kicinski <kuba@kernel.org>
Fri, 8 Aug 2025 20:22:28 +0000 (13:22 -0700)
commitc64237960819aee1766d03f446ae6de94b1e3f73
treefa8da06cd5c07782baffd1938f797674e61e8197
parent53898ebabe843bfa7baea9dae152797d5d0563c9
hamradio: ignore ops-locked netdevs

Syzkaller managed to trigger lock dependency in xsk_notify via
register_netdevice. As discussed in [0], using register_netdevice
in the notifiers is problematic so skip adding hamradio for ops-locked
devices.

       xsk_notifier+0x89/0x230 net/xdp/xsk.c:1664
       notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
       call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
       call_netdevice_notifiers net/core/dev.c:2281 [inline]
       unregister_netdevice_many_notify+0x14d7/0x1ff0 net/core/dev.c:12156
       unregister_netdevice_many net/core/dev.c:12219 [inline]
       unregister_netdevice_queue+0x33c/0x380 net/core/dev.c:12063
       register_netdevice+0x1689/0x1ae0 net/core/dev.c:11241
       bpq_new_device drivers/net/hamradio/bpqether.c:481 [inline]
       bpq_device_event+0x491/0x600 drivers/net/hamradio/bpqether.c:523
       notifier_call_chain+0x1b6/0x3e0 kernel/notifier.c:85
       call_netdevice_notifiers_extack net/core/dev.c:2267 [inline]
       call_netdevice_notifiers net/core/dev.c:2281 [inline]
       __dev_notify_flags+0x18d/0x2e0 net/core/dev.c:-1
       netif_change_flags+0xe8/0x1a0 net/core/dev.c:9608
       dev_change_flags+0x130/0x260 net/core/dev_api.c:68
       devinet_ioctl+0xbb4/0x1b50 net/ipv4/devinet.c:1200
       inet_ioctl+0x3c0/0x4c0 net/ipv4/af_inet.c:1001

0: https://lore.kernel.org/netdev/20250625140357.6203d0af@kernel.org/
Fixes: 4c975fd70002 ("net: hold instance lock during NETDEV_REGISTER/UP")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: syzbot+e6300f66a999a6612477@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e6300f66a999a6612477
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250806213726.1383379-2-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
drivers/net/hamradio/bpqether.c