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

wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect()

This patch fixes a use-after-free in ath9k that occurs in
ath9k_hif_usb_disconnect() when ath9k_destroy_wmi() is trying to access
'drv_priv' that has already been freed by ieee80211_free_hw(), called by
ath9k_htc_hw_deinit(). The patch moves ath9k_destroy_wmi() before
ieee80211_free_hw(). Note that urbs from the driver should be killed
before freeing 'wmi' with ath9k_destroy_wmi() as their callbacks will
access 'wmi'.

Found by a modified version of syzkaller.

==================================================================
BUG: KASAN: use-after-free in ath9k_destroy_wmi+0x38/0x40
Read of size 8 at addr ffff8881069132a0 by task kworker/0:1/7

CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #131
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
Workqueue: usb_hub_wq hub_event
Call Trace:
dump_stack_lvl+0x8e/0xd1
print_address_description.constprop.0.cold+0x93/0x334
? ath9k_destroy_wmi+0x38/0x40
? ath9k_destroy_wmi+0x38/0x40
kasan_report.cold+0x83/0xdf
? ath9k_destroy_wmi+0x38/0x40
ath9k_destroy_wmi+0x38/0x40
ath9k_hif_usb_disconnect+0x329/0x3f0
? ath9k_hif_usb_suspend+0x120/0x120
? usb_disable_interface+0xfc/0x180
usb_unbind_interface+0x19b/0x7e0
? usb_autoresume_device+0x50/0x50
device_release_driver_internal+0x44d/0x520
bus_remove_device+0x2e5/0x5a0
device_del+0x5b2/0xe30
? __device_link_del+0x370/0x370
? usb_remove_ep_devs+0x43/0x80
? remove_intf_ep_devs+0x112/0x1a0
usb_disable_device+0x1e3/0x5a0
usb_disconnect+0x267/0x870
hub_event+0x168d/0x3950
? rcu_read_lock_sched_held+0xa1/0xd0
? hub_port_debounce+0x2e0/0x2e0
? check_irq_usage+0x860/0xf20
? drain_workqueue+0x281/0x360
? lock_release+0x640/0x640
? rcu_read_lock_sched_held+0xa1/0xd0
? rcu_read_lock_bh_held+0xb0/0xb0
? lockdep_hardirqs_on_prepare+0x273/0x3e0
process_one_work+0x92b/0x1460
? pwq_dec_nr_in_flight+0x330/0x330
? rwlock_bug.part.0+0x90/0x90
worker_thread+0x95/0xe00
? __kthread_parkme+0x115/0x1e0
? process_one_work+0x1460/0x1460
kthread+0x3a1/0x480
? set_kthread_struct+0x120/0x120
ret_from_fork+0x1f/0x30

The buggy address belongs to the page:
page:ffffea00041a44c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106913
flags: 0x200000000000000(node=0|zone=2)
raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 7, ts 38347963444, free_ts 41399957635
prep_new_page+0x1aa/0x240
get_page_from_freelist+0x159a/0x27c0
__alloc_pages+0x2da/0x6a0
alloc_pages+0xec/0x1e0
kmalloc_order+0x39/0xf0
kmalloc_order_trace+0x19/0x120
__kmalloc+0x308/0x390
wiphy_new_nm+0x6f5/0x1dd0
ieee80211_alloc_hw_nm+0x36d/0x2230
ath9k_htc_probe_device+0x9d/0x1e10
ath9k_htc_hw_init+0x34/0x50
ath9k_hif_usb_firmware_cb+0x25f/0x4e0
request_firmware_work_func+0x131/0x240
process_one_work+0x92b/0x1460
worker_thread+0x95/0xe00
kthread+0x3a1/0x480
page last free stack trace:
free_pcp_prepare+0x3d3/0x7f0
free_unref_page+0x1e/0x3d0
device_release+0xa4/0x240
kobject_put+0x186/0x4c0
put_device+0x20/0x30
ath9k_htc_disconnect_device+0x1cf/0x2c0
ath9k_htc_hw_deinit+0x26/0x30
ath9k_hif_usb_disconnect+0x2d9/0x3f0
usb_unbind_interface+0x19b/0x7e0
device_release_driver_internal+0x44d/0x520
bus_remove_device+0x2e5/0x5a0
device_del+0x5b2/0xe30
usb_disable_device+0x1e3/0x5a0
usb_disconnect+0x267/0x870
hub_event+0x168d/0x3950
process_one_work+0x92b/0x1460

Memory state around the buggy address:
ffff888106913180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff888106913200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff888
---truncated---

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History

Wed, 31 Dec 2025 12:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Important


Tue, 30 Dec 2025 12:45:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect() This patch fixes a use-after-free in ath9k that occurs in ath9k_hif_usb_disconnect() when ath9k_destroy_wmi() is trying to access 'drv_priv' that has already been freed by ieee80211_free_hw(), called by ath9k_htc_hw_deinit(). The patch moves ath9k_destroy_wmi() before ieee80211_free_hw(). Note that urbs from the driver should be killed before freeing 'wmi' with ath9k_destroy_wmi() as their callbacks will access 'wmi'. Found by a modified version of syzkaller. ================================================================== BUG: KASAN: use-after-free in ath9k_destroy_wmi+0x38/0x40 Read of size 8 at addr ffff8881069132a0 by task kworker/0:1/7 CPU: 0 PID: 7 Comm: kworker/0:1 Tainted: G O 5.14.0+ #131 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014 Workqueue: usb_hub_wq hub_event Call Trace: dump_stack_lvl+0x8e/0xd1 print_address_description.constprop.0.cold+0x93/0x334 ? ath9k_destroy_wmi+0x38/0x40 ? ath9k_destroy_wmi+0x38/0x40 kasan_report.cold+0x83/0xdf ? ath9k_destroy_wmi+0x38/0x40 ath9k_destroy_wmi+0x38/0x40 ath9k_hif_usb_disconnect+0x329/0x3f0 ? ath9k_hif_usb_suspend+0x120/0x120 ? usb_disable_interface+0xfc/0x180 usb_unbind_interface+0x19b/0x7e0 ? usb_autoresume_device+0x50/0x50 device_release_driver_internal+0x44d/0x520 bus_remove_device+0x2e5/0x5a0 device_del+0x5b2/0xe30 ? __device_link_del+0x370/0x370 ? usb_remove_ep_devs+0x43/0x80 ? remove_intf_ep_devs+0x112/0x1a0 usb_disable_device+0x1e3/0x5a0 usb_disconnect+0x267/0x870 hub_event+0x168d/0x3950 ? rcu_read_lock_sched_held+0xa1/0xd0 ? hub_port_debounce+0x2e0/0x2e0 ? check_irq_usage+0x860/0xf20 ? drain_workqueue+0x281/0x360 ? lock_release+0x640/0x640 ? rcu_read_lock_sched_held+0xa1/0xd0 ? rcu_read_lock_bh_held+0xb0/0xb0 ? lockdep_hardirqs_on_prepare+0x273/0x3e0 process_one_work+0x92b/0x1460 ? pwq_dec_nr_in_flight+0x330/0x330 ? rwlock_bug.part.0+0x90/0x90 worker_thread+0x95/0xe00 ? __kthread_parkme+0x115/0x1e0 ? process_one_work+0x1460/0x1460 kthread+0x3a1/0x480 ? set_kthread_struct+0x120/0x120 ret_from_fork+0x1f/0x30 The buggy address belongs to the page: page:ffffea00041a44c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x106913 flags: 0x200000000000000(node=0|zone=2) raw: 0200000000000000 0000000000000000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 3, migratetype Unmovable, gfp_mask 0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), pid 7, ts 38347963444, free_ts 41399957635 prep_new_page+0x1aa/0x240 get_page_from_freelist+0x159a/0x27c0 __alloc_pages+0x2da/0x6a0 alloc_pages+0xec/0x1e0 kmalloc_order+0x39/0xf0 kmalloc_order_trace+0x19/0x120 __kmalloc+0x308/0x390 wiphy_new_nm+0x6f5/0x1dd0 ieee80211_alloc_hw_nm+0x36d/0x2230 ath9k_htc_probe_device+0x9d/0x1e10 ath9k_htc_hw_init+0x34/0x50 ath9k_hif_usb_firmware_cb+0x25f/0x4e0 request_firmware_work_func+0x131/0x240 process_one_work+0x92b/0x1460 worker_thread+0x95/0xe00 kthread+0x3a1/0x480 page last free stack trace: free_pcp_prepare+0x3d3/0x7f0 free_unref_page+0x1e/0x3d0 device_release+0xa4/0x240 kobject_put+0x186/0x4c0 put_device+0x20/0x30 ath9k_htc_disconnect_device+0x1cf/0x2c0 ath9k_htc_hw_deinit+0x26/0x30 ath9k_hif_usb_disconnect+0x2d9/0x3f0 usb_unbind_interface+0x19b/0x7e0 device_release_driver_internal+0x44d/0x520 bus_remove_device+0x2e5/0x5a0 device_del+0x5b2/0xe30 usb_disable_device+0x1e3/0x5a0 usb_disconnect+0x267/0x870 hub_event+0x168d/0x3950 process_one_work+0x92b/0x1460 Memory state around the buggy address: ffff888106913180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888106913200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888 ---truncated---
Title wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-01-02T15:05:15.332Z

Reserved: 2025-12-30T12:06:07.137Z

Link: CVE-2022-50881

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-30T13:16:03.173

Modified: 2025-12-31T20:43:05.160

Link: CVE-2022-50881

cve-icon Redhat

Severity : Important

Publid Date: 2025-12-30T00:00:00Z

Links: CVE-2022-50881 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.