Bug 2524508 (CVE-2026-74745)

Summary:	CVE-2026-74745 kernel: eth: bnxt: avoid deadlock when canceling IRQ affinity notifier
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
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 `bnxt` Ethernet driver. This vulnerability could allow a local attacker to cause a system deadlock. The deadlock occurs when the driver attempts to unregister an IRQ affinity notifier while holding a lock that is also required by the notifier's callback, leading to system unresponsiveness.	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 2026-08-26 15:03:33 UTC

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

eth: bnxt: avoid deadlock when canceling IRQ affinity notifier

Unregistering IRQ affinity notifiers waits for the callback synchronously.
bnxt takes the netdev instance lock in the notifier (to restart the queue)
and cancels the work under the same lock. This may obviously deadlock.

Move the restart to the async service task. The queue restart isn't
super time sensitive. Store the new TPH tag, schedule the task.
Safely canceling the service task is already ironed out.

In bnxt_request_irq() the order of registering notifier, affinity and
initial TPH programming has to be inverted. I think it was racy
previously since user may trigger an update as soon as notifier
is installed.

There's a small known gap - if pcie_tph_get_cpu_st() fails at init
and the target tag is 0 we may miss programming the entry.
This does not seem worth fixing, the code has skip-on-failure
all over the place, anyway.

Comment 1 gkamathe 2026-08-27 14:21:27 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026082658-CVE-2026-74745-fe41@gregkh/T