Bug 2546449 (CVE-2026-98297)

Summary:	CVE-2026-98297 kernel: Bluetooth: hci_core: Fix queuing tx_work after workqueue is drained
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 Bluetooth subsystem. A race condition occurs when network transmission requests are queued while the Bluetooth device is being shut down and its background workqueue is draining. A local attacker could exploit this vulnerability by sending data through Bluetooth sockets during device closure, leading to kernel warnings, dropped operations, and a potential 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 09:22:29 UTC

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

Bluetooth: hci_core: Fix queuing tx_work after workqueue is drained

hci_send_acl(), hci_send_sco() and hci_send_iso() queue hdev->tx_work
unconditionally. They can run from the L2CAP/SCO/ISO socket send path
while hci_dev_close_sync() is draining hdev->workqueue (HCIDEVDOWN
racing with a socket write). Since that queue_work() is not chained
work from the tx_work worker itself, __queue_work() sees the queue
marked __WQ_DRAINING, warns "cannot queue %ps on wq %s", and drops
the work:

  WARNING: CPU: 1 PID: 5985 at kernel/workqueue.c:2352 __queue_work
  Call Trace:
   queue_work_on
   l2cap_chan_send
   l2cap_sock_sendmsg
   ...

hci_dev_close_sync() already sets HCI_CMD_DRAIN_WORKQUEUE before
draining, but only hci_cmd_work() and handle_cmd_cnt_and_timer()
check it before queuing. Route the tx_work producers through the
same guard via a shared hci_sched_tx() helper.

Comment 1 gkamathe 2026-10-11 02:55:21 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98297.mbox