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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.1628 Important: kernel-rt security and bug fix update 29 June 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: kernel-rt Publisher: Red Hat Operating System: Red Hat Enterprise Linux Server 7 Impact/Access: Root Compromise -- Existing Account Denial of Service -- Existing Account Resolution: Patch/Upgrade CVE Names: CVE-2017-1000364 CVE-2017-7895 CVE-2017-7645 CVE-2017-7477 CVE-2017-6214 CVE-2017-2583 Reference: ASB-2017.0067 ESB-2017.1526.2 ESB-2017.1388 ESB-2017.1304 Original Bulletin: https://access.redhat.com/errata/RHSA-2017:1616 - --------------------------BEGIN INCLUDED TEXT-------------------- - -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ===================================================================== Red Hat Security Advisory Synopsis: Important: kernel-rt security and bug fix update Advisory ID: RHSA-2017:1616-01 Product: Red Hat Enterprise Linux Advisory URL: https://access.redhat.com/errata/RHSA-2017:1616 Issue date: 2017-06-28 CVE Names: CVE-2017-1000364 CVE-2017-2583 CVE-2017-6214 CVE-2017-7477 CVE-2017-7645 CVE-2017-7895 ===================================================================== 1. Summary: An update for kernel-rt is now available for Red Hat Enterprise Linux 7. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. 2. Relevant releases/architectures: Red Hat Enterprise Linux Realtime (v. 7) - noarch, x86_64 Red Hat Enterprise Linux for Real Time for NFV (v. 7) - noarch, x86_64 3. Description: The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements. Security Fix(es): * A flaw was found in the way memory was being allocated on the stack for user space binaries. If heap (or different memory region) and stack memory regions were adjacent to each other, an attacker could use this flaw to jump over the stack guard gap, cause controlled memory corruption on process stack or the adjacent memory region, and thus increase their privileges on the system. This is a kernel-side mitigation which increases the stack guard gap size from one page to 1 MiB to make successful exploitation of this issue more difficult. (CVE-2017-1000364, Important) * A flaw was found in the way Linux kernel allocates heap memory to build the scattergather list from a fragment list(skb_shinfo(skb)->frag_list) in the socket buffer(skb_buff). The heap overflow occurred if 'MAX_SKB_FRAGS + 1' parameter and 'NETIF_F_FRAGLIST' feature are both used together. A remote user or process could use this flaw to potentially escalate their privilege on a system. (CVE-2017-7477, Important) * The NFS2/3 RPC client could send long arguments to the NFS server. These encoded arguments are stored in an array of memory pages, and accessed using pointer variables. Arbitrarily long arguments could make these pointers point outside the array and cause an out-of-bounds memory access. A remote user or program could use this flaw to crash the kernel, resulting in denial of service. (CVE-2017-7645, Important) * The NFSv2 and NFSv3 server implementations in the Linux kernel through 4.10.13 lacked certain checks for the end of a buffer. A remote attacker could trigger a pointer-arithmetic error or possibly cause other unspecified impacts using crafted requests related to fs/nfsd/nfs3xdr.c and fs/nfsd/nfsxdr.c. (CVE-2017-7895, Important) * Linux kernel built with the Kernel-based Virtual Machine (CONFIG_KVM) support was vulnerable to an incorrect segment selector(SS) value error. The error could occur while loading values into the SS register in long mode. A user or process inside a guest could use this flaw to crash the guest, resulting in DoS or potentially escalate their privileges inside the guest. (CVE-2017-2583, Moderate) * A flaw was found in the Linux kernel's handling of packets with the URG flag. Applications using the splice() and tcp_splice_read() functionality could allow a remote attacker to force the kernel to enter a condition in which it could loop indefinitely. (CVE-2017-6214, Moderate) Red Hat would like to thank Qualys Research Labs for reporting CVE-2017-1000364; Ari Kauppi for reporting CVE-2017-7895; and Xiaohan Zhang (Huawei Inc.) for reporting CVE-2017-2583. Bug Fix(es): * The kernel-rt packages have been upgraded to the 3.10.0-514.25.2 source tree, which provides a number of bug fixes over the previous version. (BZ#1452742) * Previously, a local lock acquisition around the ip_send_unicast_reply() function was incorrectly terminated. Consequently, a list corruption occurred that led to a kernel panic. This update adds locking functions around calls to ip_send_unicast_reply(). As a result, neither list corruption nor kernel panic occur under the described circumstances. (BZ#1455239) 4. Solution: For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 The system must be rebooted for this update to take effect. 5. Bugs fixed (https://bugzilla.redhat.com/): 1414735 - CVE-2017-2583 Kernel: Kvm: vmx/svm potential privilege escalation inside guest 1426542 - CVE-2017-6214 kernel: ipv4/tcp: Infinite loop in tcp_splice_read() 1443615 - CVE-2017-7645 kernel: nfsd: Incorrect handling of long RPC replies 1445207 - CVE-2017-7477 kernel: net: Heap overflow in skb_to_sgvec in macsec.c 1446103 - CVE-2017-7895 kernel: NFSv3 server does not properly handle payload bounds checking of WRITE requests 1452742 - kernel-rt: update to the RHEL7.3.z batch#6 source tree 1455239 - net: add back the missing serialization in ip_send_unicast_reply() [RT 7.3.z] 1461333 - CVE-2017-1000364 kernel: heap/stack gap jumping via unbounded stack allocations 6. Package List: Red Hat Enterprise Linux for Real Time for NFV (v. 7): Source: kernel-rt-3.10.0-514.26.1.rt56.442.el7.src.rpm noarch: kernel-rt-doc-3.10.0-514.26.1.rt56.442.el7.noarch.rpm x86_64: kernel-rt-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-devel-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-kvm-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-kvm-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debuginfo-common-x86_64-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-devel-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-kvm-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-kvm-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-devel-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-kvm-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-kvm-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm Red Hat Enterprise Linux Realtime (v. 7): Source: kernel-rt-3.10.0-514.26.1.rt56.442.el7.src.rpm noarch: kernel-rt-doc-3.10.0-514.26.1.rt56.442.el7.noarch.rpm x86_64: kernel-rt-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debug-devel-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-debuginfo-common-x86_64-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-devel-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-debuginfo-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm kernel-rt-trace-devel-3.10.0-514.26.1.rt56.442.el7.x86_64.rpm These packages are GPG signed by Red Hat for security. Our key and details on how to verify the signature are available from https://access.redhat.com/security/team/key/ 7. References: https://access.redhat.com/security/cve/CVE-2017-1000364 https://access.redhat.com/security/cve/CVE-2017-2583 https://access.redhat.com/security/cve/CVE-2017-6214 https://access.redhat.com/security/cve/CVE-2017-7477 https://access.redhat.com/security/cve/CVE-2017-7645 https://access.redhat.com/security/cve/CVE-2017-7895 https://access.redhat.com/security/updates/classification/#important 8. Contact: The Red Hat security contact is <secalert@redhat.com>. More contact details at https://access.redhat.com/security/team/contact/ Copyright 2017 Red Hat, Inc. - -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iD8DBQFZU/mtXlSAg2UNWIIRAhYIAJ42qRehY60kmV2FptsmEemr0sL35ACdG4mg VHOx6LYlrjxRBjx/wWE9z2A= =sI9J - -----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. 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