RHSA-2017:2077 - Security Advisory

Topic

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.

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):

• An use-after-free flaw was found in the Linux kernel which enables a race condition in the L2TPv3 IP Encapsulation feature. A local user could use this flaw to escalate their privileges or crash the system. (CVE-2016-10200, Important)
• A flaw was found that can be triggered in keyring_search_iterator in keyring.c if type->match is NULL. A local user could use this flaw to crash the system or, potentially, escalate their privileges. (CVE-2017-2647, Important)
• It was found that the NFSv4 server in the Linux kernel did not properly validate layout type when processing NFSv4 pNFS LAYOUTGET and GETDEVICEINFO operands. A remote attacker could use this flaw to soft-lockup the system and thus cause denial of service. (CVE-2017-8797, Important)

This update also fixes multiple Moderate and Low impact security issues:

• CVE-2015-8839, CVE-2015-8970, CVE-2016-9576, CVE-2016-7042, CVE-2016-7097, CVE-2016-8645, CVE-2016-9576, CVE-2016-9588, CVE-2016-9806, CVE-2016-10088, CVE-2016-10147, CVE-2017-2596, CVE-2017-2671, CVE-2017-5970, CVE-2017-6001, CVE-2017-6951, CVE-2017-7187, CVE-2017-7616, CVE-2017-7889, CVE-2017-8890, CVE-2017-9074, CVE-2017-8890, CVE-2017-9075, CVE-2017-8890, CVE-2017-9076, CVE-2017-8890, CVE-2017-9077, CVE-2017-9242, CVE-2014-7970, CVE-2014-7975, CVE-2016-6213, CVE-2016-9604, CVE-2016-9685

Documentation for these issues is available from the Release Notes document linked from the References section.

Red Hat would like to thank Igor Redko (Virtuozzo) and Andrey Ryabinin (Virtuozzo) for reporting CVE-2017-2647; Igor Redko (Virtuozzo) and Vasily Averin (Virtuozzo) for reporting CVE-2015-8970; Marco Grassi for reporting CVE-2016-8645; and Dmitry Vyukov (Google Inc.) for reporting CVE-2017-2596. The CVE-2016-7042 issue was discovered by Ondrej Kozina (Red Hat); the CVE-2016-7097 issue was discovered by Andreas Gruenbacher (Red Hat) and Jan Kara (SUSE); the CVE-2016-6213 and CVE-2016-9685 issues were discovered by Qian Cai (Red Hat); and the CVE-2016-9604 issue was discovered by David Howells (Red Hat).

Additional Changes:

For detailed information on other changes in this release, see the Red Hat Enterprise Linux 7.4 Release Notes linked from the References section.

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.

Affected Products

• Red Hat Enterprise Linux for Real Time 7 x86_64
• Red Hat Enterprise Linux for Real Time for NFV 7 x86_64
• Red Hat Enterprise Linux for Real Time for x86_64 - Extended Life Cycle Support 7 x86_64

Fixes

• BZ - 1151095 - CVE-2014-7970 Kernel: fs: VFS denial of service
• BZ - 1151108 - CVE-2014-7975 Kernel: fs: umount denial of service
• BZ - 1323577 - CVE-2015-8839 kernel: ext4 filesystem page fault race condition with fallocate call.
• BZ - 1356471 - CVE-2016-6213 kernel: Overflowing kernel mount table using shared bind mount
• BZ - 1368938 - CVE-2016-7097 kernel: Setting a POSIX ACL via setxattr doesn't clear the setgid bit
• BZ - 1373966 - CVE-2016-7042 kernel: Stack corruption while reading /proc/keys when gcc stack protector is enabled
• BZ - 1377840 - kernel-rt: update to the RHEL7.3.z batch#1 source tree
• BZ - 1378172 - KVM-RT: halting and starting guests cause latency spikes
• BZ - 1386286 - CVE-2015-8970 kernel: crypto: GPF in lrw_crypt caused by null-deref
• BZ - 1389215 - RT kernel panics with dm-multipath enabled
• BZ - 1389433 - CVE-2016-9604 kernel: security: The built-in keyrings for security tokens can be joined as a session and then modified by the root user
• BZ - 1393904 - CVE-2016-8645 kernel: a BUG() statement can be hit in net/ipv4/tcp_input.c
• BZ - 1396941 - CVE-2016-9685 kernel: Memory leaks in xfs_attr_list.c error paths
• BZ - 1400188 - kernel-rt: update to the RHEL7.3.z batch#2 source tree
• BZ - 1401502 - CVE-2016-9806 kernel: netlink: double-free in netlink_dump
• BZ - 1403145 - CVE-2016-9576 kernel: Use after free in SCSI generic device interface
• BZ - 1404200 - CVE-2016-10147 kernel: Kernel crash by spawning mcrypt(alg) with incompatible algorithm
• BZ - 1404924 - CVE-2016-9588 Kernel: kvm: nVMX: uncaught software exceptions in L1 guest leads to DoS
• BZ - 1412210 - CVE-2016-10088 kernel: Use after free in SCSI generic device interface (CVE-2016-9576 regression)
• BZ - 1414052 - kernel-rt: update to the RHEL7.3.z batch#3 source tree
• BZ - 1417812 - CVE-2017-2596 Kernel: kvm: page reference leakage in handle_vmon
• BZ - 1421638 - CVE-2017-5970 kernel: ipv4: Invalid IP options could cause skb->dst drop
• BZ - 1421801 - [rt] update driver modifications from upstream PREEMPT_RT patchset
• BZ - 1421810 - [rt] implement the simple work queue from upstream PREEMPT_RT series
• BZ - 1422825 - CVE-2017-6001 kernel: Race condition between multiple sys_perf_event_open() calls
• BZ - 1425780 - latencyhist: disable jump-labels
• BZ - 1426661 - BUG: sleeping function called from invalid context at kernel/locking/rtmutex.c:915
• BZ - 1427626 - [rt] x86_64 specific updates from upstream PREEMPT_RT patchset
• BZ - 1427647 - [rt] dump stack: don't disable preemption during trace
• BZ - 1427991 - lockdep: selftest: fix warnings due to missing PREEMPT_RT conditionals
• BZ - 1428353 - CVE-2017-2647 kernel: Null pointer dereference in search_keyring
• BZ - 1428890 - update softirq: Check preemption after reenabling interrupts
• BZ - 1428943 - Consider backport "ftrace: Fix trace header alignment"
• BZ - 1429610 - kernel-rt: update to the RHEL7.3.z batch#4 source tree
• BZ - 1429640 - [rt] ipc/msg: Implement lockless pipelined wakeups
• BZ - 1429951 - [rt] fs: dcache: Use cpu_chill() in trylock loops
• BZ - 1429977 - workqueue: use rcu_readlock() in put_pwq_unlocked()
• BZ - 1430023 - snd/pcm: fix snd_pcm_stream_lock*() irqs_disabled() splats
• BZ - 1430038 - Add missing hunk for upstream skbufhead-raw-lock RT patches
• BZ - 1430074 - Backport "net: dev: always take qdisc's busylock in __dev_xmit_skb" upstream RT patch
• BZ - 1430347 - CVE-2016-10200 kernel: l2tp: Race condition in the L2TPv3 IP encapsulation feature
• BZ - 1430353 - net: add back the missing serialization in ip_send_unicast_reply()
• BZ - 1430926 - percpu_ida: Use local locks
• BZ - 1430946 - sas-ata/isci: dont't disable interrupts in qc_issue handler
• BZ - 1431104 - cpu hotplug: Document why PREEMPT_RT uses a spinlock
• BZ - 1432118 - hotplug: Use set_cpus_allowed_ptr() in sync_unplug_thread()
• BZ - 1433252 - CVE-2017-6951 kernel: NULL pointer dereference in keyring_search_aux function
• BZ - 1434327 - CVE-2017-7187 kernel: scsi: Stack-based buffer overflow in sg_ioctl function
• BZ - 1434616 - CPU hotplug causes lglock to be taken from atomic context
• BZ - 1436649 - CVE-2017-2671 kernel: ping socket / AF_LLC connect() sin_family race
• BZ - 1438512 - [rt] pull patchset that lifts single reader restriction on rwsems
• BZ - 1441088 - CVE-2017-7616 kernel: Incorrect error handling in the set_mempolicy and mbind compat syscalls in mm/mempolicy.c
• BZ - 1441552 - kernel BUG at kernel/sched/rt.c:2021!
• BZ - 1444493 - CVE-2017-7889 kernel: mm subsystem does not properly enforce the CONFIG_STRICT_DEVMEM protection mechanism
• BZ - 1450972 - CVE-2017-8890 kernel: Double free in the inet_csk_clone_lock function in net/ipv4/inet_connection_sock.c
• BZ - 1452240 - kvmgt.ko needs unknown symbol
• BZ - 1452679 - CVE-2017-9074 kernel: net: IPv6 fragmentation implementation of nexthdr field may be associated with an invalid option
• BZ - 1452688 - CVE-2017-9076 kernel: net: IPv6 DCCP implementation mishandles inheritance
• BZ - 1452691 - CVE-2017-9075 kernel: net: sctp_v6_create_accept_sk function mishandles inheritance
• BZ - 1452744 - CVE-2017-9077 kernel: net: tcp_v6_syn_recv_sock function mishandles inheritance
• BZ - 1456388 - CVE-2017-9242 kernel: Incorrect overwrite check in __ip6_append_data()
• BZ - 1459056 - Boot/Shutdown RT guest with kernel-rt-debug will cause "BUG: sleeping function called from invalid context at kernel/rtmutex.c:818"
• BZ - 1466329 - CVE-2017-8797 kernel: NFSv4 server does not properly validate layout type when processing NFSv4 pNFS LAYOUTGET operand

CVEs

• CVE-2014-7970
• CVE-2014-7975
• CVE-2015-8839
• CVE-2015-8970
• CVE-2016-6213
• CVE-2016-7042
• CVE-2016-7097
• CVE-2016-8645
• CVE-2016-9576
• CVE-2016-9588
• CVE-2016-9604
• CVE-2016-9685
• CVE-2016-9806
• CVE-2016-10088
• CVE-2016-10147
• CVE-2016-10200
• CVE-2016-10741
• CVE-2017-2584
• CVE-2017-2596
• CVE-2017-2647
• CVE-2017-2671
• CVE-2017-5551
• CVE-2017-5970
• CVE-2017-6001
• CVE-2017-6951
• CVE-2017-7187
• CVE-2017-7495
• CVE-2017-7616
• CVE-2017-7889
• CVE-2017-8797
• CVE-2017-8890
• CVE-2017-9074
• CVE-2017-9075
• CVE-2017-9076
• CVE-2017-9077
• CVE-2017-9242

References

• https://access.redhat.com/security/updates/classification/#important
• https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/7/html/7.4_Release_Notes/index.html