CVE-2025-38385

In the Linux kernel, the following vulnerability has been resolved:

net: usb: lan78xx: fix WARN in __netif_napi_del_locked on disconnect

Remove redundant netif_napi_del() call from disconnect path.

A WARN may be triggered in __netif_napi_del_locked() during USB device disconnect:

WARNING: CPU: 0 PID: 11 at net/core/dev.c:7417 __netif_napi_del_locked+0x2b4/0x350

This happens because netif_napi_del() is called in the disconnect path while NAPI is still enabled. However, it is not necessary to call netif_napi_del() 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 __netif_napi_del_locked+0x2b4/0x350 Modules linked in: flexcan can_dev 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: usb_hub_wq hub_event pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=–) pc : __netif_napi_del_locked+0x2b4/0x350 lr : __netif_napi_del_locked+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: __netif_napi_del_locked+0x2b4/0x350 (P) lan78xx_disconnect+0xf4/0x360 usb_unbind_interface+0x158/0x718 device_remove+0x100/0x150 device_release_driver_internal+0x308/0x478 device_release_driver+0x1c/0x30 bus_remove_device+0x1a8/0x368 device_del+0x2e0/0x7b0 usb_disable_device+0x244/0x540 usb_disconnect+0x220/0x758 hub_event+0x105c/0x35e0 process_one_work+0x760/0x17b0 worker_thread+0x768/0xce8 kthread+0x3bc/0x690 ret_from_fork+0x10/0x20 irq event stamp: 211604 hardirqs last enabled at (211603): [] _raw_spin_unlock_irqrestore+0x84/0x98 hardirqs last disabled at (211604): [] el1_dbg+0x24/0x80 softirqs last enabled at (211296): [] handle_softirqs+0x820/0xbc8 softirqs last disabled at (210993): [] __do_softirq+0x18/0x20 —[ end trace 0000000000000000 ]— lan78xx 1-1:1.0 enu1: failed to kill vid 0081/0

Weakness

The product does not release or incorrectly releases a resource before it is made available for re-use.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
• For example, languages such as Java, Ruby, and Lisp perform automatic garbage collection that releases memory for objects that have been deallocated.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/125.html
• https://cwe.mitre.org/data/definitions/130.html
• https://cwe.mitre.org/data/definitions/131.html
• https://cwe.mitre.org/data/definitions/494.html
• https://cwe.mitre.org/data/definitions/495.html
• https://cwe.mitre.org/data/definitions/496.html
• https://cwe.mitre.org/data/definitions/666.html

References

• https://git.kernel.org/stable/c/17a37b9a5dd945d86110838fb471e7139ba993a2
• https://git.kernel.org/stable/c/510a6095d754df9d727f644ec5076b7929d6c9ea
• https://git.kernel.org/stable/c/6c7ffc9af7186ed79403a3ffee9a1e5199fc7450
• https://git.kernel.org/stable/c/7135056a49035597198280820c61b8c5dbe4a1d0
• https://git.kernel.org/stable/c/968a419c95131e420f12bbdba19e96e2f6b071c4
• https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html