Bug 2502207 (CVE-2026-63832)

Summary:	CVE-2026-63832 kernel: wifi: mt76: add wcid publish check in mt76_sta_add
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's mt76 Wi-Fi driver. This vulnerability occurs due to improper handling of Wi-Fi station additions, where the driver fails to adequately verify existing client connections. A remote attacker could exploit this by manipulating Wi-Fi authentication processes, leading to corruption of internal kernel data structures. This corruption can cause system instability and a denial of service, making the affected system unresponsive.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-07-19 13:01:53 UTC

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

wifi: mt76: add wcid publish check in mt76_sta_add

Since mt7925_mac_sta_add publishes wcid, add publish check in mt76_sta_add
to avoid reinitializing the wcid->poll_list.

Found dev->sta_poll_list corruption when using mt7925 and 7.1-rc4.
According to the corruption information, prev->next was changed to itself.

wlan0: disconnect from AP 90:fb:5d:94:8b:e3 for new auth to 90:fb:5d:94:8b:e2
wlan0: authenticate with 90:fb:5d:94:8b:e2 (local address=84:9e:56:9c:7e:6b)
wlan0: send auth to 90:fb:5d:94:8b:e2 (try 1/3)
 slab kmalloc-8k start ffff8c80958a6000 pointer offset 4160 size 8192
list_add corruption. prev->next should be next (ffff8c808a7488f8), but was ffff8c80958a7040. (prev=ffff8c80958a7040).

 mt76_wcid_add_poll+0x95/0xd0 [mt76]
 mt7925_mac_add_txs.part.0+0xa5/0xe0 [mt7925_common]
 mt7925_rx_check+0xa7/0xc0 [mt7925_common]
 mt76_dma_rx_poll+0x50d/0x790 [mt76]
 mt792x_poll_rx+0x52/0xe0 [mt792x_lib]

Comment 1 Keith Grant 2026-07-20 16:39:47 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026071908-CVE-2026-63832-d93b@gregkh/T