Bug 1678423 (CVE-2019-3837)

Summary:	CVE-2019-3837 kernel: memory leak in tcp_recvmsg() with NET_DMA
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	acaringi, airlied, apmukher, bhu, blc, brdeoliv, bskeggs, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jglisse, jkacur, john.j5live, jonathan, josef, jross, jstancek, jwboyer, kernel-maint, kernel-mgr, khorenko, labbott, lgoncalv, linville, matt, mchehab, mcressma, mjg59, mlangsdo, mmezynsk, nmurray, plougher, rt-maint, rvrbovsk, security-response-team, steved, vdronov, vvs, williams
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	It was found that the net_dma code in tcp_recvmsg() in the RHEL6 kernel is thread-unsafe. So an unprivileged multi-threaded userspace application calling recvmsg() for the same network socket in parallel executed on ioatdma-enabled hardware with net_dma enabled can leak the memory, crash the host leading to a denial of service or cause a random memory corruption.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2019-09-05 12:59:26 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1678168
Bug Blocks:	1678424

Description Pedro Sampaio 2019-02-18 17:59:16 UTC

It was found that the net_dma code in tcp_recvmsg() in the RHEL6 kernel is thread-unsafe. So an unprivileged multi-threaded userspace application calling recvmsg() for the same network socket in parallel executed on ioatdma-enabled hardware with net_dma enabled can leak the memory, crash the host leading to a denial-of-service, or cause a random memory corruption.

References:

https://seclists.org/oss-sec/2019/q2/7

https://bugs.openvz.org/browse/OVZ-7080

An upstream fix:

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=77873803363c

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=7bced397510a

Comment 1 Vladis Dronov 2019-02-19 10:30:28 UTC

Acknowledgements:

Name: Vasily Averin (Virtuozzo Kernel Team)