In the Linux kernel, the following vulnerability has been resolved:
net: usb: lan78xx: fix WARN in _netifnapidellocked on disconnect
Remove redundant netifnapidel() call from disconnect path.
A WARN may be triggered in _netifnapidellocked() during USB device disconnect:
WARNING: CPU: 0 PID: 11 at net/core/dev.c:7417 _netifnapidellocked+0x2b4/0x350
This happens because netifnapidel() is called in the disconnect path while NAPI is still enabled. However, it is not necessary to call netifnapidel() explicitly, since unregister_netdev() will handle NAPI teardown automatically and safely. Removing the redundant call avoids triggering the warning.
Full trace: lan78xx 1-1:1.0 enu1: Failed to read register index 0x000000c4. ret = -ENODEV lan78xx 1-1:1.0 enu1: Failed to set MAC down with error -ENODEV lan78xx 1-1:1.0 enu1: Link is Down lan78xx 1-1:1.0 enu1: Failed to read register index 0x00000120. ret = -ENODEV ------------[ cut here ]------------ WARNING: CPU: 0 PID: 11 at net/core/dev.c:7417 _netifnapidellocked+0x2b4/0x350 Modules linked in: flexcan candev fuse CPU: 0 UID: 0 PID: 11 Comm: kworker/0:1 Not tainted 6.16.0-rc2-00624-ge926949dab03 #9 PREEMPT Hardware name: SKOV IMX8MP CPU revC - bd500 (DT) Workqueue: usbhubwq hubevent pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : _netifnapidellocked+0x2b4/0x350 lr : _netifnapidellocked+0x7c/0x350 sp : ffffffc085b673c0 x29: ffffffc085b673c0 x28: ffffff800b7f2000 x27: ffffff800b7f20d8 x26: ffffff80110bcf58 x25: ffffff80110bd978 x24: 1ffffff0022179eb x23: ffffff80110bc000 x22: ffffff800b7f5000 x21: ffffff80110bc000 x20: ffffff80110bcf38 x19: ffffff80110bcf28 x18: dfffffc000000000 x17: ffffffc081578940 x16: ffffffc08284cee0 x15: 0000000000000028 x14: 0000000000000006 x13: 0000000000040000 x12: ffffffb0022179e8 x11: 1ffffff0022179e7 x10: ffffffb0022179e7 x9 : dfffffc000000000 x8 : 0000004ffdde8619 x7 : ffffff80110bcf3f x6 : 0000000000000001 x5 : ffffff80110bcf38 x4 : ffffff80110bcf38 x3 : 0000000000000000 x2 : 0000000000000000 x1 : 1ffffff0022179e7 x0 : 0000000000000000 Call trace: _netifnapidellocked+0x2b4/0x350 (P) lan78xxdisconnect+0xf4/0x360 usbunbindinterface+0x158/0x718 deviceremove+0x100/0x150 devicereleasedriverinternal+0x308/0x478 devicereleasedriver+0x1c/0x30 busremovedevice+0x1a8/0x368 devicedel+0x2e0/0x7b0 usbdisabledevice+0x244/0x540 usbdisconnect+0x220/0x758 hubevent+0x105c/0x35e0 processonework+0x760/0x17b0 workerthread+0x768/0xce8 kthread+0x3bc/0x690 retfromfork+0x10/0x20 irq event stamp: 211604 hardirqs last enabled at (211603): [<ffffffc0828cc9ec>] _rawspinunlockirqrestore+0x84/0x98 hardirqs last disabled at (211604): [<ffffffc0828a9a84>] el1dbg+0x24/0x80 softirqs last enabled at (211296): [<ffffffc080095f10>] handlesoftirqs+0x820/0xbc8 softirqs last disabled at (210993): [<ffffffc080010288>] _dosoftirq+0x18/0x20 ---[ end trace 0000000000000000 ]--- lan78xx 1-1:1.0 enu1: failed to kill vid 0081/0