Synopsis: Important: kernel security and bug fix update

Advisory ID:       SLSA-2019:1488-1

Issue Date:        2019-06-17

CVE Numbers:       CVE-2019-11477

                   CVE-2019-11478

                   CVE-2019-11479

                   CVE-2019-3896

--



Security Fix(es):



* An integer overflow flaw was found in the way the Linux kernel's

networking subsystem processed TCP Selective Acknowledgment (SACK)

segments. While processing SACK segments, the Linux kernel's socket buffer

(SKB) data structure becomes fragmented. Each fragment is about TCP

maximum segment size (MSS) bytes. To efficiently process SACK blocks, the

Linux kernel merges multiple fragmented SKBs into one, potentially

overflowing the variable holding the number of segments. A remote attacker

could use this flaw to crash the Linux kernel by sending a crafted

sequence of SACK segments on a TCP connection with small value of TCP MSS,

resulting in a denial of service (DoS). (CVE-2019-11477)



* kernel: Double free in lib/idr.c (CVE-2019-3896)



* Kernel: tcp: excessive resource consumption while processing SACK blocks

allows remote denial of service (CVE-2019-11478)



* Kernel: tcp: excessive resource consumption for TCP connections with low

MSS allows remote denial of service (CVE-2019-11479)



Bug Fix(es):



* MDS mitigations not enabled on Intel Skylake CPUs



* kernel does not disable SMT with mds=full,nosmt



* md_clear flag missing from /proc/cpuinfo

--



SL6

  x86_64

    kernel-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-debug-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-debug-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    kernel-debug-debuginfo-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-debug-devel-2.6.32-754.15.3.el6.i686.rpm

    kernel-debug-devel-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    kernel-debuginfo-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-debuginfo-common-i686-2.6.32-754.15.3.el6.i686.rpm

    kernel-debuginfo-common-x86_64-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-devel-2.6.32-754.15.3.el6.x86_64.rpm

    kernel-headers-2.6.32-754.15.3.el6.x86_64.rpm

    perf-2.6.32-754.15.3.el6.x86_64.rpm

    perf-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    perf-debuginfo-2.6.32-754.15.3.el6.x86_64.rpm

    python-perf-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    python-perf-debuginfo-2.6.32-754.15.3.el6.x86_64.rpm

    python-perf-2.6.32-754.15.3.el6.x86_64.rpm

  i386

    kernel-2.6.32-754.15.3.el6.i686.rpm

    kernel-debug-2.6.32-754.15.3.el6.i686.rpm

    kernel-debug-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    kernel-debug-devel-2.6.32-754.15.3.el6.i686.rpm

    kernel-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    kernel-debuginfo-common-i686-2.6.32-754.15.3.el6.i686.rpm

    kernel-devel-2.6.32-754.15.3.el6.i686.rpm

    kernel-headers-2.6.32-754.15.3.el6.i686.rpm

    perf-2.6.32-754.15.3.el6.i686.rpm

    perf-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    python-perf-debuginfo-2.6.32-754.15.3.el6.i686.rpm

    python-perf-2.6.32-754.15.3.el6.i686.rpm

  noarch

    kernel-abi-whitelists-2.6.32-754.15.3.el6.noarch.rpm

    kernel-doc-2.6.32-754.15.3.el6.noarch.rpm

    kernel-firmware-2.6.32-754.15.3.el6.noarch.rpm



- Scientific Linux Development Team