Expired Pointer Dereference Affecting kernel-rt-selftests-internal package, versions *


Severity

Recommended
high

Based on Red Hat Enterprise Linux security rating.

Threat Intelligence

EPSS
0.02% (4th percentile)

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  • Snyk IDSNYK-RHEL9-KERNELRTSELFTESTSINTERNAL-13585555
  • published17 Oct 2025
  • disclosed15 Oct 2025

Introduced: 15 Oct 2025

NewCVE-2025-40000  (opens in a new tab)
CWE-825  (opens in a new tab)

How to fix?

There is no fixed version for RHEL:9 kernel-rt-selftests-internal.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-rt-selftests-internal package and not the kernel-rt-selftests-internal package as distributed by RHEL. See How to fix? for RHEL:9 relevant fixed versions and status.

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

wifi: rtw89: fix use-after-free in rtw89_core_tx_kick_off_and_wait()

There is a bug observed when rtw89_core_tx_kick_off_and_wait() tries to access already freed skb_data:

BUG: KFENCE: use-after-free write in rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110

CPU: 6 UID: 0 PID: 41377 Comm: kworker/u64:24 Not tainted 6.17.0-rc1+ #1 PREEMPT(lazy) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS edk2-20250523-14.fc42 05/23/2025 Workqueue: events_unbound cfg80211_wiphy_work [cfg80211]

Use-after-free write at 0x0000000020309d9d (in kfence-#251): rtw89_core_tx_kick_off_and_wait drivers/net/wireless/realtek/rtw89/core.c:1110 rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338 rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979 rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165 rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.h:141 rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012 rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059 rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758 process_one_work kernel/workqueue.c:3241 worker_thread kernel/workqueue.c:3400 kthread kernel/kthread.c:463 ret_from_fork arch/x86/kernel/process.c:154 ret_from_fork_asm arch/x86/entry/entry_64.S:258

kfence-#251: 0x0000000056e2393d-0x000000009943cb62, size=232, cache=skbuff_head_cache

allocated by task 41377 on cpu 6 at 77869.159548s (0.009551s ago): __alloc_skb net/core/skbuff.c:659 __netdev_alloc_skb net/core/skbuff.c:734 ieee80211_nullfunc_get net/mac80211/tx.c:5844 rtw89_core_send_nullfunc drivers/net/wireless/realtek/rtw89/core.c:3431 rtw89_core_scan_complete drivers/net/wireless/realtek/rtw89/core.c:5338 rtw89_hw_scan_complete_cb drivers/net/wireless/realtek/rtw89/fw.c:7979 rtw89_chanctx_proceed_cb drivers/net/wireless/realtek/rtw89/chan.c:3165 rtw89_chanctx_proceed drivers/net/wireless/realtek/rtw89/chan.c:3194 rtw89_hw_scan_complete drivers/net/wireless/realtek/rtw89/fw.c:8012 rtw89_mac_c2h_scanofld_rsp drivers/net/wireless/realtek/rtw89/mac.c:5059 rtw89_fw_c2h_work drivers/net/wireless/realtek/rtw89/fw.c:6758 process_one_work kernel/workqueue.c:3241 worker_thread kernel/workqueue.c:3400 kthread kernel/kthread.c:463 ret_from_fork arch/x86/kernel/process.c:154 ret_from_fork_asm arch/x86/entry/entry_64.S:258

freed by task 1045 on cpu 9 at 77869.168393s (0.001557s ago): ieee80211_tx_status_skb net/mac80211/status.c:1117 rtw89_pci_release_txwd_skb drivers/net/wireless/realtek/rtw89/pci.c:564 rtw89_pci_release_tx_skbs.isra.0 drivers/net/wireless/realtek/rtw89/pci.c:651 rtw89_pci_release_tx drivers/net/wireless/realtek/rtw89/pci.c:676 rtw89_pci_napi_poll drivers/net/wireless/realtek/rtw89/pci.c:4238 __napi_poll net/core/dev.c:7495 net_rx_action net/core/dev.c:7557 net/core/dev.c:7684 handle_softirqs kernel/softirq.c:580 do_softirq.part.0 kernel/softirq.c:480 __local_bh_enable_ip kernel/softirq.c:407 rtw89_pci_interrupt_threadfn drivers/net/wireless/realtek/rtw89/pci.c:927 irq_thread_fn kernel/irq/manage.c:1133 irq_thread kernel/irq/manage.c:1257 kthread kernel/kthread.c:463 ret_from_fork arch/x86/kernel/process.c:154 ret_from_fork_asm arch/x86/entry/entry_64.S:258

It is a consequence of a race between the waiting and the signaling side of the completion:

        Waiting thread                            Completing thread

rtw89_core_tx_kick_off_and_wait() rcu_assign_pointer(skb_data->wait, wait) /* start waiting / wait_for_completion_timeout() rtw89_pci_tx_status() rtw89_core_tx_wait_complete() rcu_read_lock() / signals completion and

---truncated---

CVSS Base Scores

version 3.1