Bug 294941 (CVE-2007-3739)

Summary: CVE-2007-3739 LTC36188-Don't allow the stack to grow into hugetlb reserved regions
Product: [Other] Security Response Reporter: Mark J. Cox <mjc>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: CLOSED ERRATA QA Contact:
Severity: medium Docs Contact:
Priority: urgent    
Version: unspecifiedCC: kreilly
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
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Clone Of: Environment:
Last Closed: 2007-11-01 13:33:51 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: 247658, 253313, 294951, 294971, 294981    
Bug Blocks:    

Description Mark J. Cox 2007-09-18 15:44:35 UTC 
From Adam Litke's mail to LKML (http://lkml.org/lkml/2007/1/29/180):

[PATCH] Don't allow the stack to grow into hugetlb reserved regions
    
    When expanding the stack, we don't currently check if the VMA will cross
    into an area of the address space that is reserved for hugetlb pages.
    Subsequent faults on the expanded portion of such a VMA will confuse the
    low-level MMU code, resulting in an OOPS.  Check for this.
Comment 1 Mark J. Cox 2007-09-18 15:46:02 UTC 
see bz#253313 for more details
Comment 4 Jan Lieskovsky 2007-11-07 12:06:06 UTC 
This CVE also affects RHEL-3 (advisory has not been filled yet). On the 
ppc there is in mm/mmap.c file function called "expand_stack" which has
the same function as that one mentioned in the patch. This also checks first,
if there is enough memory to allocate, then checks if the stack wasn't 
expanded by some other thread and if not, checks the address space limits.
If none from these tests passes, the stack is expanded. But before this 
increase one yet check should be added -- if the address space we would
like to allocate doesn't belong to the huge_tlb_only space.