Bug 2546442 (CVE-2026-98334)

Summary:	CVE-2026-98334 kernel: wifi: mac80211: reset state when starting AP fails
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, 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 mac80211 wireless subsystem. When starting a wireless Access Point (AP) fails after setting beacon parameters, the kernel does not properly reset its internal state. A local attacker can exploit this condition by triggering subsequent scanning operations on the affected interface, resulting in a system crash and a Denial of Service (DoS).	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 2026-10-06 09:21:27 UTC

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

wifi: mac80211: reset state when starting AP fails

ieee80211_start_ap() can set enable_beacon (and beacon_int) and fail
later, leaving it set forever. Scanning can then attempt to restore
beaconing on such an interface, leading to:

  Oops: divide error: 0000 [#1] SMP KASAN NOPTI
  RIP: 0010:mac80211_hwsim_link_info_changed+0xca7/0xf00
  Call Trace:
   drv_link_info_changed+0x413/0x860 net/mac80211/driver-ops.c:495
   ieee80211_link_info_change_notify+0x24b/0x3c0 net/mac80211/main.c:427
   ieee80211_offchannel_return+0x381/0x580 net/mac80211/offchannel.c:160
   __ieee80211_scan_completed+0x993/0xe30 net/mac80211/scan.c:519
   ieee80211_scan_work+0x472/0x2010 net/mac80211/scan.c:1193
   cfg80211_wiphy_work+0x2b7/0x550 net/wireless/core.c:538

in hwsim. Also, cfg80211 then allows changing the interface type,
and the off-channel path getgs confused about beaconing as well,
leading to another warning:

  WARNING: net/mac80211/driver-ops.c:468 at drv_link_info_changed+0x583/0x880
   ieee80211_link_info_change_notify+0x24b/0x3c0 net/mac80211/main.c:427
   ieee80211_offchannel_stop_vifs+0x328/0x5c0 net/mac80211/offchannel.c:122
   ieee80211_start_sw_scan net/mac80211/scan.c:583 [inline]
   __ieee80211_start_scan+0xfb6/0x1af0 net/mac80211/scan.c:882

Reset the state on failures to always have it correct.

Comment 1 gkamathe 2026-10-10 09:38:22 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98334.mbox