CVE-2025-40140
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BaseFortify

Publication date: 2025-11-12

Last updated on: 2025-11-12

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: net: usb: Remove disruptive netif_wake_queue in rtl8150_set_multicast syzbot reported WARNING in rtl8150_start_xmit/usb_submit_urb. This is the sequence of events that leads to the warning: rtl8150_start_xmit() { netif_stop_queue(); usb_submit_urb(dev->tx_urb); } rtl8150_set_multicast() { netif_stop_queue(); netif_wake_queue(); <-- wakes up TX queue before URB is done } rtl8150_start_xmit() { netif_stop_queue(); usb_submit_urb(dev->tx_urb); <-- double submission } rtl8150_set_multicast being the ndo_set_rx_mode callback should not be calling netif_stop_queue and notif_start_queue as these handle TX queue synchronization. The net core function dev_set_rx_mode handles the synchronization for rtl8150_set_multicast making it safe to remove these locks.
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Meta Information
Published
2025-11-12
Last Modified
2025-11-12
Generated
2026-06-16
AI Q&A
2025-11-13
EPSS Evaluated
2026-06-15
NVD
CVE-2025-40140
Affected Vendors & Products
Currently, no data is known.
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Exploitability
CWE
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KEV
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CWE ID Description
CWE-UNKNOWN
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Executive Summary

This vulnerability involves improper handling of the transmit (TX) queue in the Linux kernel's rtl8150 USB network driver. Specifically, the function rtl8150_set_multicast incorrectly calls netif_stop_queue and netif_wake_queue, which disrupts the TX queue synchronization. This leads to a situation where the TX queue is woken up before the USB request block (URB) transmission is complete, causing a double submission of the URB in rtl8150_start_xmit. The issue arises because rtl8150_set_multicast should not manage TX queue synchronization; this is already safely handled by the net core function dev_set_rx_mode. The fix removes the disruptive calls to netif_wake_queue in rtl8150_set_multicast to prevent this problem.

Impact Analysis

This vulnerability can cause improper synchronization of the network transmit queue, potentially leading to double submission of USB network packets. This may result in network instability, degraded performance, or unexpected behavior in network communications on affected systems using the rtl8150 USB network driver.

Detection Guidance

This vulnerability can be detected by monitoring for warnings related to rtl8150_start_xmit/usb_submit_urb in the system logs, as syzbot reported such warnings. Checking kernel logs (e.g., using 'dmesg' or 'journalctl') for messages related to rtl8150_start_xmit or usb_submit_urb may help identify the issue. Specific commands to check logs include: 'dmesg | grep rtl8150_start_xmit' or 'journalctl -k | grep usb_submit_urb'.

Mitigation Strategies

The immediate mitigation is to update the Linux kernel to a version where the vulnerability is resolved by removing the disruptive netif_wake_queue call in rtl8150_set_multicast, as the net core function dev_set_rx_mode now safely handles TX queue synchronization. Until then, avoid using affected kernel versions or disable the affected USB network device if possible.

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