Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2019.4286 linux security update 14 November 2019 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: linux kernel Publisher: Debian Operating System: Debian GNU/Linux 9 Debian GNU/Linux 10 Impact/Access: Root Compromise -- Existing Account Access Privileged Data -- Existing Account Denial of Service -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2019-11135 CVE-2019-0155 CVE-2019-0154 CVE-2018-12207 Reference: ASB-2019.0322 ASB-2019.0313 ESB-2019.4274 ESB-2019.4273 ESB-2019.4271 Original Bulletin: http://www.debian.org/security/2019/dsa-4564 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 - - ------------------------------------------------------------------------- Debian Security Advisory DSA-4564-1 security@debian.org https://www.debian.org/security/ Ben Hutchings November 12, 2019 https://www.debian.org/security/faq - - ------------------------------------------------------------------------- Package : linux CVE ID : CVE-2018-12207 CVE-2019-0154 CVE-2019-0155 CVE-2019-11135 Several vulnerabilities have been discovered in the Linux kernel that may lead to a privilege escalation, denial of service, or information leak. CVE-2018-12207 It was discovered that on Intel CPUs supporting hardware virtualisation with Extended Page Tables (EPT), a guest VM may manipulate the memory management hardware to cause a Machine Check Error (MCE) and denial of service (hang or crash). The guest triggers this error by changing page tables without a TLB flush, so that both 4 KB and 2 MB entries for the same virtual address are loaded into the instruction TLB (iTLB). This update implements a mitigation in KVM that prevents guest VMs from loading 2 MB entries into the iTLB. This will reduce performance of guest VMs. Further information on the mitigation can be found at <https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/multihit.html> or in the linux-doc-4.9 or linux-doc-4.19 package. A qemu update adding support for the PSCHANGE_MC_NO feature, which allows to disable iTLB Multihit mitigations in nested hypervisors will be provided via DSA 4566-1. Intel's explanation of the issue can be found at <https://software.intel.com/security-software-guidance/insights/deep-dive-machine-check-error-avoidance-page-size-change-0>. CVE-2019-0154 Intel discovered that on their 8th and 9th generation GPUs, reading certain registers while the GPU is in a low-power state can cause a system hang. A local user permitted to use the GPU can use this for denial of service. This update mitigates the issue through changes to the i915 driver. The affected chips (gen8 and gen9) are listed at <https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units#Gen8>. CVE-2019-0155 Intel discovered that their 9th generation and newer GPUs are missing a security check in the Blitter Command Streamer (BCS). A local user permitted to use the GPU could use this to access any memory that the GPU has access to, which could result in a denial of service (memory corruption or crash), a leak of sensitive information, or privilege escalation. This update mitigates the issue by adding the security check to the i915 driver. The affected chips (gen9 onward) are listed at <https://en.wikipedia.org/wiki/List_of_Intel_graphics_processing_units#Gen9>. CVE-2019-11135 It was discovered that on Intel CPUs supporting transactional memory (TSX), a transaction that is going to be aborted may continue to execute speculatively, reading sensitive data from internal buffers and leaking it through dependent operations. Intel calls this "TSX Asynchronous Abort" (TAA). For CPUs affected by the previously published Microarchitectural Data Sampling (MDS) issues (CVE-2018-12126, CVE-2018-12127, CVE-2018-12130, CVE-2019-11091), the existing mitigation also mitigates this issue. For processors that are vulnerable to TAA but not MDS, this update disables TSX by default. This mitigation requires updated CPU microcode. An updated intel-microcode package (only available in Debian non-free) will be provided via DSA 4565-1. The updated CPU microcode may also be available as part of a system firmware ("BIOS") update. Further information on the mitigation can be found at <https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/tsx_async_abort.html> or in the linux-doc-4.9 or linux-doc-4.19 package. Intel's explanation of the issue can be found at <https://software.intel.com/security-software-guidance/insights/deep-dive-intel-transactional-synchronization-extensions-intel-tsx-asynchronous-abort>. For the oldstable distribution (stretch), these problems have been fixed in version 4.9.189-3+deb9u2. For the stable distribution (buster), these problems have been fixed in version 4.19.67-2+deb10u2. We recommend that you upgrade your linux packages. For the detailed security status of linux please refer to its security tracker page at: https://security-tracker.debian.org/tracker/linux Further information about Debian Security Advisories, how to apply these updates to your system and frequently asked questions can be found at: https://www.debian.org/security/ Mailing list: debian-security-announce@lists.debian.org - -----BEGIN PGP SIGNATURE----- iQKTBAEBCgB9FiEERkRAmAjBceBVMd3uBUy48xNDz0QFAl3LBMVfFIAAAAAALgAo aXNzdWVyLWZwckBub3RhdGlvbnMub3BlbnBncC5maWZ0aGhvcnNlbWFuLm5ldDQ2 NDQ0MDk4MDhDMTcxRTA1NTMxRERFRTA1NENCOEYzMTM0M0NGNDQACgkQBUy48xND z0RtSg//aBsENrrs5mbCKYxt6Lm1hVdxdmz+9TbgZkxU+lQ0XEfge4wQUCa8KhJh os4qGuDXh5q/2VkNMa+cUCyHCyxxl3qv4rCsm+MxG1Rd4Hy4JoKt4heJgi5hXW9A qhOQ5+rHb0OeoPM9BCduTi37h+mLS4ItRz30n3+3B2+VC0tj+iV2nOZJmC0WMEiq LrqeDm39pa6DqKBAExdYT/TCyKLsngMHoIGorWVPXdJP1/xmrH2gU0W3L7k5KJPz apeCi4E3H9bjRh8Be5SeT3zDoEaiiNn/sHHkLDeAryFMuwilekxFaYocbW/0CEIH kWRMkC+uq1KfQfBDSxIOsH8yq8n+zQ12XJ0YiiqEKg6ErabWz5rCaVHyPWvdh0Ny mezs99PkQ7mUkjAUVzIfz2Rq6VByOCdfuT/GvPL7rUtIJYRdqYkWBI8t/hVlrnDq yR+X7vQZWm5wb3+Jiz/sA6TqgDvKSgk1+tUfBmqI9sh1wWNKSSYee0b81BLLubs3 IInPlgW2Lp+IsA3CVKKQNTNMWZkuNyPZH2UGpZV45otazcLPrrdNtt52x4gvIJ/W lizVpb2BOpTpoeEXNYlEDCjwcrW9f1FkVztwMgz3J6eb9pHjieFuGO9vOxcP7li3 FNJbGhaUUZa8BfjsQgBwFSwVXRr212zK9yv0UHnLRJo4l0I3xC0= =YZWL - -----END PGP SIGNATURE----- - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: https://www.auscert.org.au/bulletins/ =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBXczk42aOgq3Tt24GAQh6Wg//TPyJhRwCN1H4UX1R7yMC7zQBXFDONNys gBE716zmNfg+auAPlm2PR0y0MAoGfNAlulaotXSlibmbvAC7rs9pLKXdzQpWDmTr U8j0kW+DPvvM7sC2y7PfEmxtFTap5a8RTTGzpjrp9R+5vblzThL8Ktxykd4D0F+G CDlOJKEU9teNz9PHfQPD3PB42lRFpn+28eJRFjYBWAu4/uxYjePrFpMGk71gvj6C HGkqc7rabC2v7LB6SPZdTdV+3vHiy3NGNny5wX61u0CzmIcQfWqOSkP8sMd/n8Ms t399nrPsz/lFTYtfFVxW2M9kBzntvolf9Eq0Rj0lK/ZyyvSbR0Gupr3YdMhDuAGk kxnpjTTXPfPPyv5azZ7F7hUsTqpQjfrg6k9s34SexS52orVcgEu/R22LqCzzC6CB /l4awQ/FNAK8dAWCEedSnAZkAEHkN8H9Fz3vpteSzWRB5PMu/3KzHy1dP0dZ6j14 UcWfYjp+lEZfvsCeKtBTxrVz2t+m0m7M5L1oDRPf5qkq904c5crJpMiFaWQ8As8U 9qpZBYdIj/BHaiCPpcilj+FH4i1yWQhg6zJAVHh35keCsbJrwUVlvXQIMFnSV7lp hqU0tudpoJ5xmy4udLH7Dc+hn5zpCoyzR0PdJX7cqK2rSfB9h+5iNfRcvMC2mFl5 ZvdP3wkZ+nE= =6Mk1 -----END PGP SIGNATURE-----