Bug 1250030 (CVE-2015-5707)

Summary: CVE-2015-5707 kernel: number wraparound vulnerability in function start_req()
Product: [Other] Security Response Reporter: Adam Mariš <amaris>
Component: vulnerabilityAssignee: Red Hat Product Security <security-response-team>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: aquini, arm-mgr, bhu, dhoward, fhrbata, gansalmon, iboverma, itamar, jforbes, jkacur, joelsmith, jonathan, jross, jwboyer, kernel-maint, kernel-mgr, lgoncalv, madhu.chinakonda, matt, mchehab, mcressma, nmurray, plougher, rt-maint, rvrbovsk, slong, williams, wmealing
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
An integer-overflow vulnerability was found in the scsi block-request handling code in function start_req(). A local attacker could use specially crafted IOV requests to overflow a counter used in bio_map_user_iov()'s page calculation, and write past the end of the array that contains kernel-page pointers.
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:
Bug Depends On: 1250034, 1293521    
Bug Blocks: 1250036    

Description Adam Mariš 2015-08-04 11:45:20 UTC
This bug, which was probably introduced in Linux 2.6.28, was assigned CVE.
In drivers/scsi/sg.c in function start_req(), there was code segment vulnerable to number wraparound in the calculation of total number of pages in bio_map_user_iov().
This can result to allocating small array of pointers to pages that would be overflowed. It was fixed in Linux 4.1-rc1.

CVE assignment:
http://seclists.org/oss-sec/2015/q3/278

Upstream patches:
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=fdc81f45e9f57858da6351836507fbcf1b7583ee
http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=451a2886b6bf90e2fb378f7c46c655450fb96e81

Comment 1 Adam Mariš 2015-08-04 11:55:22 UTC
Created kernel tracking bugs for this issue:

Affects: fedora-all [bug 1250034]

Comment 2 Wade Mealing 2015-12-22 01:27:17 UTC
Statement:

This issue affects the Linux kernels as shipped with Red Hat Enterprise Linux 6, 7 MRG-2 and realtime kernels and does not plan be addressed in a future update.