Bugzilla – Bug 922944
VUL-1: CVE-2015-2666: kernel: overflow in microcode loader
Last modified: 2019-05-13 07:58:38 UTC
via oss-sec crafted microcode could overflow kernel stack. (needs root to exploit) From: Quentin Casasnovas <quentin.casasnovas@oracle.com> Subject: [oss-security] CVE Request: Linux kernel execution in the early microcode loader. Hi, The Linux kernel Intel early microcode loader was vulnerable to a stack overflow. This issue was fixed in upstream commit f84598bd7c https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=f84598bd7c851f8b0bf8cd0d7c3be0d73c432ff4 And was introduced in kernel 3.8+ in ec400dd ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU"). It potentially allows kernel execution using a specially crafted microcode, and I could not see that CONFIG_CC_STACKPROTECTOR_REGULAR was of any help since it left get_matching_model_microcode() unprotected on my build. It was protected using CONFIG_CC_STACKPROTECTOR_STRONG with gcc-4.9.2. It is not relevant that the tampered microcode would be refused by the CPU (since it is signed by Intel) because kernel execution would happen before that. The attack vector could be from anyone between Intel and people shipping/packaging the microcode, or could potentially be used to get a resilient backdoor on system already compromised by sticking a tampered microcode on the initrd. It would also allow root to get kernel execution by recreating the initrd. I admit these are overly paranoid scenarios, but I _think_ there's still a privilege crossing from root to kernel exec which could make sense on certain security model. I could not see an answer from cve-assign when this issue was discussed on security@kernel.org. Could a CVE be assigned to this please? Quentin
We seem to have backported to problem to SLES 12. patches.arch/x86-microcode-move-to-a-proper-location.patch
No TD branch seems to be affected
No, this was broken since it got added: ec400dd ("x86/microcode_intel_early.c: Early update ucode on Intel's CPU") in 3.9. I'll backport it to the relevant trees.
Backported to cve/linux-3.12 and the opensusies. Closing.
mitere assigned CVE-2015-2666 can you add this to the references?
Done.
openSUSE-SU-2015:0713-1: An update that solves 13 vulnerabilities and has 52 fixes is now available. Category: security (important) Bug References: 867199,893428,895797,900811,901925,903589,903640,904899,905681,907039,907818,907988,908582,908588,908589,908592,908593,908594,908596,908598,908603,908604,908605,908606,908608,908610,908612,909077,909078,909477,909634,910150,910322,910440,911311,911325,911326,911356,911438,911578,911835,912061,912202,912429,912705,913059,913466,913695,914175,915425,915454,915456,915577,915858,916608,917830,917839,918954,918970,919463,920581,920604,921313,922542,922944 CVE References: CVE-2014-8134,CVE-2014-8160,CVE-2014-8559,CVE-2014-9419,CVE-2014-9420,CVE-2014-9428,CVE-2014-9529,CVE-2014-9584,CVE-2014-9585,CVE-2015-0777,CVE-2015-1421,CVE-2015-1593,CVE-2015-2150 Sources used: openSUSE 13.2 (src): bbswitch-0.8-3.6.6, cloop-2.639-14.6.6, crash-7.0.8-6.6, hdjmod-1.28-18.7.6, ipset-6.23-6.6, kernel-docs-3.16.7-13.2, kernel-obs-build-3.16.7-13.7, kernel-obs-qa-3.16.7-13.1, kernel-obs-qa-xen-3.16.7-13.1, kernel-source-3.16.7-13.1, kernel-syms-3.16.7-13.1, pcfclock-0.44-260.6.2, vhba-kmp-20140629-2.6.2, virtualbox-4.3.20-10.2, xen-4.4.1_08-12.2, xtables-addons-2.6-6.2
This issue affects SUSE Linux Enterprise 12 and openSUSE. Older versions of SUSE Linux Enterprise are not affected.
SUSE-SU-2015:1071-1: An update that solves 13 vulnerabilities and has 31 fixes is now available. Category: security (important) Bug References: 899192,900881,909312,913232,914742,915540,916225,917125,919007,919018,920262,921769,922583,922734,922944,924664,924803,924809,925567,926156,926240,926314,927084,927115,927116,927257,927285,927308,927455,928122,928130,928135,928141,928708,929092,929145,929525,929883,930224,930226,930669,930786,931014,931130 CVE References: CVE-2014-3647,CVE-2014-8086,CVE-2014-8159,CVE-2015-1465,CVE-2015-2041,CVE-2015-2042,CVE-2015-2666,CVE-2015-2830,CVE-2015-2922,CVE-2015-3331,CVE-2015-3332,CVE-2015-3339,CVE-2015-3636 Sources used: SUSE Linux Enterprise Software Development Kit 12 (src): kernel-docs-3.12.43-52.6.2, kernel-obs-build-3.12.43-52.6.2 SUSE Linux Enterprise Server 12 (src): kernel-source-3.12.43-52.6.1, kernel-syms-3.12.43-52.6.1 SUSE Linux Enterprise Live Patching 12 (src): kgraft-patch-SLE12_Update_5-1-2.3 SUSE Linux Enterprise Desktop 12 (src): kernel-source-3.12.43-52.6.1, kernel-syms-3.12.43-52.6.1
openSUSE-SU-2016:0301-1: An update that solves 57 vulnerabilities and has 21 fixes is now available. Category: security (important) Bug References: 814440,851610,869564,873385,906545,907818,909077,909477,911326,912202,915517,915577,917830,918333,919007,919018,919463,919596,921313,921949,922583,922936,922944,926238,926240,927780,927786,928130,929525,930399,931988,932348,933896,933904,933907,933934,935542,935705,936502,936831,937032,937033,937969,938706,940338,944296,945825,947155,949936,950998,951194,951440,951627,952384,952579,952976,953052,953527,954138,954404,955224,955354,955422,956708,956934,957988,957990,958504,958510,958886,958951,959190,959399,959568,960839,961509,961739,962075 CVE References: CVE-2014-2568,CVE-2014-8133,CVE-2014-8989,CVE-2014-9090,CVE-2014-9419,CVE-2014-9529,CVE-2014-9683,CVE-2014-9715,CVE-2014-9728,CVE-2014-9729,CVE-2014-9730,CVE-2014-9731,CVE-2015-0272,CVE-2015-0777,CVE-2015-1420,CVE-2015-1421,CVE-2015-2041,CVE-2015-2042,CVE-2015-2150,CVE-2015-2666,CVE-2015-2830,CVE-2015-2922,CVE-2015-2925,CVE-2015-3212,CVE-2015-3339,CVE-2015-3636,CVE-2015-4001,CVE-2015-4002,CVE-2015-4003,CVE-2015-4004,CVE-2015-4036,CVE-2015-4167,CVE-2015-4692,CVE-2015-4700,CVE-2015-5157,CVE-2015-5283,CVE-2015-5307,CVE-2015-5364,CVE-2015-5366,CVE-2015-5707,CVE-2015-6937,CVE-2015-7550,CVE-2015-7799,CVE-2015-7833,CVE-2015-7872,CVE-2015-7885,CVE-2015-7990,CVE-2015-8104,CVE-2015-8215,CVE-2015-8543,CVE-2015-8550,CVE-2015-8551,CVE-2015-8552,CVE-2015-8569,CVE-2015-8575,CVE-2015-8767,CVE-2016-0728 Sources used: openSUSE 13.1 (src): cloop-2.639-11.22.2, crash-7.0.2-2.22.2, hdjmod-1.28-16.22.2, ipset-6.21.1-2.26.2, iscsitarget-1.4.20.3-13.22.2, kernel-debug-3.11.10-32.1, kernel-default-3.11.10-32.1, kernel-desktop-3.11.10-32.1, kernel-docs-3.11.10-32.3, kernel-ec2-3.11.10-32.1, kernel-pae-3.11.10-32.1, kernel-source-3.11.10-32.1, kernel-syms-3.11.10-32.1, kernel-trace-3.11.10-32.1, kernel-vanilla-3.11.10-32.1, kernel-xen-3.11.10-32.1, ndiswrapper-1.58-22.1, pcfclock-0.44-258.22.1, vhba-kmp-20130607-2.23.1, virtualbox-4.2.36-2.55.1, xen-4.3.4_10-56.1, xtables-addons-2.3-2.22.1