Bug 2323946 (CVE-2024-50094)

Summary:	CVE-2024-50094 kernel: sfc: Don't invoke xdp_do_flush() from netpoll.
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:	dfreiber, drow, jburrell, vkumar
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
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Bug Depends On:	2324011
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Description OSIDB Bzimport 2024-11-05 18:03:53 UTC

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

sfc: Don't invoke xdp_do_flush() from netpoll.

Yury reported a crash in the sfc driver originated from
netpoll_send_udp(). The netconsole sends a message and then netpoll
invokes the driver's NAPI function with a budget of zero. It is
dedicated to allow driver to free TX resources, that it may have used
while sending the packet.

In the netpoll case the driver invokes xdp_do_flush() unconditionally,
leading to crash because bpf_net_context was never assigned.

Invoke xdp_do_flush() only if budget is not zero.

Comment 1 Robb Gatica 2024-11-05 20:55:16 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024110551-CVE-2024-50094-5963@gregkh/T