Bug 1677778 (CVE-2019-10140)

Summary: CVE-2019-10140 kernel: overlayfs: NULL pointer dereference in ovl_posix_acl_create function in fs/overlayfs/dir.c
Product: [Other] Security Response Reporter: Laura Pardo <lpardo>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: abhgupta, acaringi, airlied, bhu, blc, brdeoliv, bskeggs, dbaker, dhoward, dvlasenk, esammons, fhrbata, hdegoede, hkrzesin, iboverma, ichavero, itamar, jarodwilson, jeremy, jforbes, jkacur, jlelli, john.j5live, jokerman, jonathan, josef, jross, jshortt, jstancek, jwboyer, kernel-maint, kernel-mgr, lgoncalv, linville, mchehab, mcressma, mjg59, mlangsdo, mvanderw, nmurray, rt-maint, rvrbovsk, security-response-team, steved, sthangav, trankin, vvs, williams, wmealing
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
A vulnerability was found in Linux kernel's implementation of overlayfs. An attacker with local access can create a denial of service situation via NULL pointer dereference in ovl_posix_acl_create function in fs/overlayfs/dir.c. This can allow attackers with ability to create directories on overlayfs to crash the kernel creating a denial of service (DOS).
 Story Points: ---
Clone Of: Environment:
Last Closed: 2021-10-25 09:51:27 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: 1677705, 1685356, 1685357, 1696289, 1696290, 1696291, 1696292, 1726955, 1729240    
Bug Blocks: 1677780    
Attachments:
Description Flags
Fix for flaw. none

Description Laura Pardo 2019-02-15 20:49:33 UTC 
A vulnerability was found in Linux Kernels implementation of overlayfs. An attacker with local access can create a denial of service situation via NULL  pointer dereference in ovl_posix_acl_create function in fs/overlayfs/dir.c. The ovl_create function can return a positive number leading to a null pointer derference of path in may_open.

This can allow attackers with ability to create directories on overlayfs to crash the kernel creating a Denial Of Service (DOS).

This flaw likely only affects Red Hat Enterprise Linux 7 based products as this issue was created by by human-error in the backporting process.


References:
https://bugzilla.redhat.com/show_bug.cgi?id=1677705

Proposed fix:
https://bugzilla.redhat.com/show_bug.cgi?id=1677778
Comment 5 Laura Pardo 2019-05-24 18:21:02 UTC 
Acknowledgments:

Name: Vasily Averin (Virtuozzo)
Comment 10 Wade Mealing 2019-08-15 03:51:05 UTC 
Mitigation: 

Some systems may wish to use device-mapper as an alternative to overlayfs.  This does not remove the flaw if overlayfs module is still in use.
Comment 11 Wade Mealing 2019-08-15 07:14:11 UTC 
Created attachment 1604006 [details]
Fix for flaw.