CVE-2025-38604: wifi: rtl818x: Kill URBs before clearing tx status queue

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-08-19 · updated 2026-07-30
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: rtl818x: Kill URBs before clearing tx status queue In rtl8187_stop() move the call of usb_kill_anchored_urbs() before clearing b_tx_status.queue. This change prevents callbacks from using already freed skb due to anchor was not killed before freeing such skb. BUG: kernel NULL pointer dereference, address: 0000000000000080 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 7 UID: 0 PID: 0 Comm: swapper/7 Not tainted 6.15.0 #8 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015 RIP: 0010:ieee80211_tx_status_irqsafe+0x21/0xc0 [mac80211] Call Trace: <IRQ> rtl8187_tx_cb+0x116/0x150 [rtl8187] __usb_hcd_giveback_urb+0x9d/0x120 usb_giveback_urb_bh+0xbb/0x140 process_one_work+0x19b/0x3c0 bh_worker+0x1a7/0x210 tasklet_action+0x10/0x30 handle_softirqs+0xf0/0x340 __irq_exit_rcu+0xcd/0xf0 common_interrupt+0x85/0xa0 </IRQ> Tested on RTL8187BvE device. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Affected products

Debian Linux: 11.0
Linux kernel: from 2.6.29 before 5.4.297; from 5.5 before 5.10.241; from 5.11 before 5.15.190; from 5.16 before 6.1.148; from 6.2 before 6.6.102; from 6.7 before 6.12.42 — fixed in 5.10.241, 5.15.190, 5.4.297, 6.1.148, 6.12.42, 6.15.10

How to fix

Upgrade to a fixed version: Linux kernel 5.10.241, 5.15.190, 5.4.297, 6.1.148. Check the vendor advisory for mitigations.

References

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