-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 ===================================================================== Red Hat Security Advisory Synopsis: Important: kernel-rt security and bug fix update Advisory ID: RHSA-2017:0931-01 Product: Red Hat Enterprise Linux Advisory URL: https://access.redhat.com/errata/RHSA-2017:0931 Issue date: 2017-04-12 CVE Names: CVE-2016-8650 CVE-2016-9793 CVE-2017-2618 CVE-2017-2636 ===================================================================== 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 race condition flaw was found in the N_HLDC Linux kernel driver when accessing n_hdlc.tbuf list that can lead to double free. A local, unprivileged user able to set the HDLC line discipline on the tty device could use this flaw to increase their privileges on the system. (CVE-2017-2636, Important) * A flaw was found in the Linux kernel key management subsystem in which a local attacker could crash the kernel or corrupt the stack and additional memory (denial of service) by supplying a specially crafted RSA key. This flaw panics the machine during the verification of the RSA key. (CVE-2016-8650, Moderate) * A flaw was found in the Linux kernel's implementation of setsockopt for the SO_{SND|RCV}BUFFORCE setsockopt() system call. Users with non-namespace CAP_NET_ADMIN are able to trigger this call and create a situation in which the sockets sendbuff data size could be negative. This could adversely affect memory allocations and create situations where the system could crash or cause memory corruption. (CVE-2016-9793, Moderate) * A flaw was found in the Linux kernel's handling of clearing SELinux attributes on /proc/pid/attr files. An empty (null) write to this file can crash the system by causing the system to attempt to access unmapped kernel memory. (CVE-2017-2618, Moderate) Red Hat would like to thank Alexander Popov for reporting CVE-2017-2636 and Ralf Spenneberg for reporting CVE-2016-8650. The CVE-2017-2618 issue was discovered by Paul Moore (Red Hat Engineering). Bug Fix(es): * Previously, a cgroups data structure was sometimes corrupted due to a race condition in the kernel-rt cgroups code. Consequently, several system tasks were blocked, and the operating system became unresponsive. This update adds a lock that prevents the race condition. As a result, the cgroups data structure no longer gets corrupted and the operating system no longer hangs under the described circumstances. (BZ#1420784) * The kernel-rt packages have been upgraded to the 3.10.0-514.16.1 source tree, which provides a number of bug fixes over the previous version. (BZ#1430749) 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/): 1395187 - CVE-2016-8650 kernel: Null pointer dereference via keyctl 1402013 - CVE-2016-9793 kernel: Signed overflow for SO_{SND|RCV}BUFFORCE 1419916 - CVE-2017-2618 kernel: Off-by-one error in selinux_setprocattr (/proc/self/attr/fscreate) 1428319 - CVE-2017-2636 kernel: Race condition access to n_hdlc.tbuf causes double free in n_hdlc_release() 1430749 - kernel-rt: update to the RHEL7.3.z batch#4 source tree [RT-7.3.z] 6. Package List: Red Hat Enterprise Linux for Real Time for NFV (v. 7): Source: kernel-rt-3.10.0-514.16.1.rt56.437.el7.src.rpm noarch: kernel-rt-doc-3.10.0-514.16.1.rt56.437.el7.noarch.rpm x86_64: kernel-rt-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-kvm-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-kvm-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debuginfo-common-x86_64-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-kvm-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-kvm-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-kvm-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-kvm-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm Red Hat Enterprise Linux Realtime (v. 7): Source: kernel-rt-3.10.0-514.16.1.rt56.437.el7.src.rpm noarch: kernel-rt-doc-3.10.0-514.16.1.rt56.437.el7.noarch.rpm x86_64: kernel-rt-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debug-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-debuginfo-common-x86_64-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-devel-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-debuginfo-3.10.0-514.16.1.rt56.437.el7.x86_64.rpm kernel-rt-trace-devel-3.10.0-514.16.1.rt56.437.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-2016-8650 https://access.redhat.com/security/cve/CVE-2016-9793 https://access.redhat.com/security/cve/CVE-2017-2618 https://access.redhat.com/security/cve/CVE-2017-2636 https://access.redhat.com/security/updates/classification/#important 8. Contact: The Red Hat security contact is . More contact details at https://access.redhat.com/security/team/contact/ Copyright 2017 Red Hat, Inc. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iD8DBQFY7jjUXlSAg2UNWIIRAvx4AJ0UGk1zTaNQOjqhPxzDBAnSVe0UWACfeNls kwrQgjLNJxXW/CVLujHvI7M= =zagv -----END PGP SIGNATURE----- -- RHSA-announce mailing list RHSA-announce@redhat.com https://www.redhat.com/mailman/listinfo/rhsa-announce