Synopsis

Important: kernel-rt security and bug fix update

Type/Severity

Security Advisory: Important

Topic

An update for kernel-rt is now available for Red Hat Enterprise MRG 2.

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):

• Out-of-bounds kernel heap access vulnerability was found in xfrm, kernel's IP framework for transforming packets. An error dealing with netlink messages from an unprivileged user leads to arbitrary read/write and privilege escalation. (CVE-2017-7184, Important)
  
• A race condition issue leading to a use-after-free flaw was found in the way the raw packet sockets are implemented in the Linux kernel networking subsystem handling synchronization. A local user able to open a raw packet socket (requires the CAP_NET_RAW capability) could use this flaw to elevate their privileges on the system. (CVE-2017-1000111, Important)
  
• An exploitable memory corruption flaw was found in the Linux kernel. The append path can be erroneously switched from UFO to non-UFO in ip_ufo_append_data() when building an UFO packet with MSG_MORE option. If unprivileged user namespaces are available, this flaw can be exploited to gain root privileges. (CVE-2017-1000112, Important)
  
• Kernel memory corruption due to a buffer overflow was found in brcmf_cfg80211_mgmt_tx() function in Linux kernels from v3.9-rc1 to v4.13-rc1. The vulnerability can be triggered by sending a crafted NL80211_CMD_FRAME packet via netlink. This flaw is unlikely to be triggered remotely as certain userspace code is needed for this. An unprivileged local user could use this flaw to induce kernel memory corruption on the system, leading to a crash. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although it is unlikely. (CVE-2017-7541, Moderate)
  
• An integer overflow vulnerability in ip6_find_1stfragopt() function was found. A local attacker that has privileges (of CAP_NET_RAW) to open raw socket can cause an infinite loop inside the ip6_find_1stfragopt() function. (CVE-2017-7542, Moderate)
  
• A kernel data leak due to an out-of-bound read was found in the Linux kernel in inet_diag_msg_sctp{,l}addr_fill() and sctp_get_sctp_info() functions present since version 4.7-rc1 through version 4.13. A data leak happens when these functions fill in sockaddr data structures used to export socket's diagnostic information. As a result, up to 100 bytes of the slab data could be leaked to a userspace. (CVE-2017-7558, Moderate)
  
• The mq_notify function in the Linux kernel through 4.11.9 does not set the sock pointer to NULL upon entry into the retry logic. During a user-space close of a Netlink socket, it allows attackers to possibly cause a situation where a value may be used after being freed (use-after-free) which may lead to memory corruption or other unspecified other impact. (CVE-2017-11176, Moderate)
  
• A divide-by-zero vulnerability was found in the __tcp_select_window function in the Linux kernel. This can result in a kernel panic causing a local denial of service. (CVE-2017-14106, Moderate)
  
• A flaw was found where the XFS filesystem code mishandles a user-settable inode flag in the Linux kernel prior to 4.14-rc1. This can cause a local denial of service via a kernel panic. (CVE-2017-14340, Moderate)
  

Red Hat would like to thank Chaitin Security Research Lab for reporting CVE-2017-7184; Willem de Bruijn for reporting CVE-2017-1000111; and Andrey Konovalov for reporting CVE-2017-1000112. The CVE-2017-7558 issue was discovered by Stefano Brivio (Red Hat) and the CVE-2017-14340 issue was discovered by Dave Chinner (Red Hat).

Bug Fix(es):

• kernel-rt packages have been upgraded to the 3.10.0-693.5.2 source tree, which provides number of bug fixes over the previous version. (BZ#1489085)

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

• MRG Realtime 2 x86_64

Fixes

• BZ - 1435153 - CVE-2017-7184 kernel: Out-of-bounds heap access in xfrm
• BZ - 1470659 - CVE-2017-11176 kernel: Use-after-free in sys_mq_notify()
• BZ - 1473198 - CVE-2017-7541 kernel: Possible heap buffer overflow in brcmf_cfg80211_mgmt_tx()
• BZ - 1473649 - CVE-2017-7542 kernel: Integer overflow in ip6_find_1stfragopt() causes infinite loop
• BZ - 1479304 - CVE-2017-1000111 kernel: Heap out-of-bounds in AF_PACKET sockets
• BZ - 1479307 - CVE-2017-1000112 kernel: Exploitable memory corruption due to UFO to non-UFO path switch
• BZ - 1480266 - CVE-2017-7558 kernel: Out of bounds read in inet_diag_msg_sctp{,l}addr_fill() and sctp_get_sctp_info() in SCTP stack
• BZ - 1487295 - CVE-2017-14106 kernel: Divide-by-zero in __tcp_select_window
• BZ - 1489085 - update the MRG 2.5.z 3.10 kernel-rt sources
• BZ - 1491344 - CVE-2017-14340 kernel: xfs: unprivileged user kernel oops

CVEs

• CVE-2017-1000111
• CVE-2017-1000112
• CVE-2017-11176
• CVE-2017-14106
• CVE-2017-14340
• CVE-2017-7184
• CVE-2017-7541
• CVE-2017-7542
• CVE-2017-7558

References

• https://access.redhat.com/security/updates/classification/#important

MRG Realtime 2

SRPM
kernel-rt-3.10.0-693.5.2.rt56.592.el6rt.src.rpm	SHA-256: edfa46b24bbf37dd6190456f78e3fcf36e0022ed24903a7f14578e8a786dc541
x86_64
kernel-rt-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 9727406089dbb9387e0f9d208e3ad7ddeaea0f2f1d67a6290d8fdfe26bba9561
kernel-rt-debug-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: cb9f3a425a382571175d4f34a3236d7448f46050943c888c94a6577f14b861ad
kernel-rt-debug-debuginfo-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 8c38b6907308e728970fa43ddd84f9ab77d4b657579d2b8036b06d465033a9ad
kernel-rt-debug-devel-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 1ba300d5a6973ce5d1ea11493ee0a42972d47b3cbd75b4017d17f8cbf2121a20
kernel-rt-debuginfo-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: a7baa43b60cd2e0594a96b27bddb41a06b058cb4e8b3ea8e3a3a37f58db9f240
kernel-rt-debuginfo-common-x86_64-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 1842dc892b1fd1a0e7cc9494ac6c3285458fee7a2221e5e60b3ea5830d9c8831
kernel-rt-devel-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: d30059718992c02f2b67bd45608b6280e279964f20719d0561e5bf378b55c42f
kernel-rt-doc-3.10.0-693.5.2.rt56.592.el6rt.noarch.rpm	SHA-256: eea74d11bd8f96dcc2dae15a5f6a0d4b89544ed306eaa34eabc85f8b067b6619
kernel-rt-firmware-3.10.0-693.5.2.rt56.592.el6rt.noarch.rpm	SHA-256: 18b4294b5f188eb9a5f2011f24cd9c7e341961bae38d6ab1ad360d25c6cfd95a
kernel-rt-trace-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 31805fe97c76c5937823915c88e263fa2e9174ccc301f0d54f7bdd6a0a2ad179
kernel-rt-trace-debuginfo-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 85020396f7122b0b5c111b51776df67e31b4d78622645ab92aa05eee18ea9b80
kernel-rt-trace-devel-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: b621cdb0a4cdd19183d2c4a551c9bcf55989ea05523fb52bc498aa91fefa409d
kernel-rt-vanilla-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 8aeaddfbabc7188c9acb773a23fdfb5cae8f72d4a99ec27e64d74eb101018b62
kernel-rt-vanilla-debuginfo-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: 26464f1a01e29478b8a96f44518d1598c228ef31c988d9b989543cd79c31611b
kernel-rt-vanilla-devel-3.10.0-693.5.2.rt56.592.el6rt.x86_64.rpm	SHA-256: eb9a44422e974a1ab05394bb9cbd61288450ad476aba69b63599e438de8eca1e