CVE-2025-38513: Debian Linux

Medium severity, CVSS 5.5. EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev() There is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For example, the following is possible: T0 T1 zd_mac_tx_to_dev() /* len == skb_queue_len(q) */ while (len > ZD_MAC_MAX_ACK_WAITERS) { filter_ack() spin_lock_irqsave(&q->lock, flags); /* position == skb_queue_len(q) */ for (i=1; i<position; i++) skb = __skb_dequeue(q) if (mac->type == NL80211_IFTYPE_AP) skb = __skb_dequeue(q); spin_unlock_irqrestore(&q->lock, flags); skb_dequeue() -> NULL Since there is a small gap between checking skb queue length and skb being unconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL. Then the pointer is passed to zd_mac_tx_status() where it is dereferenced. In order to avoid potential NULL pointer dereference due to situations like above, check if skb is not NULL before passing it to zd_mac_tx_status(). Found by Linux Verification Center (linuxtesting.org) with SVACE.

Affected products

• Debian Debian Linux: version 11.0 only
• Linux Linux Kernel: from 2.6.25, before 5.4.296 (fixed in 5.4.296); from 5.5, before 5.10.240 (fixed in 5.10.240); from 5.11, before 5.15.189 (fixed in 5.15.189); from 5.16, before 6.1.146 (fixed in 6.1.146); from 6.2, before 6.6.99 (fixed in 6.6.99); from 6.7, before 6.12.39 (fixed in 6.12.39); …

Published 2025-08-16. Last modified 2026-06-17.