Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: rtw89: fix use-after...
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---
Impact
CVE-2025-40000 has a CVSS score of 8.8 (High). The vector is reachable from an adjacent network, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. No fixed version is listed yet, so configuration controls and monitoring matter more in the interim.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Frequently Asked Questions
- What is CVE-2025-40000? CVE-2025-40000 is a high-severity security vulnerability. No fixed version is listed yet.
- How severe is CVE-2025-40000? CVE-2025-40000 has a CVSS score of 8.8 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Is there a fix for CVE-2025-40000? No fixed version is listed for CVE-2025-40000 yet. Monitor the advisory for updates and apply mitigations in the interim.
- Is CVE-2025-40000 exploitable, and should I be worried? Whether CVE-2025-40000 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2025-40000 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.