Debian Security Advisory
DSA-3981-1 linux -- security update
- Date Reported:
- 20 Sep 2017
- Affected Packages:
- Security database references:
- In the Debian bugtracking system: Bug 866511, Bug 875881.
In Mitre's CVE dictionary: CVE-2017-7518, CVE-2017-7558, CVE-2017-10661, CVE-2017-11600, CVE-2017-12134, CVE-2017-12146, CVE-2017-12153, CVE-2017-12154, CVE-2017-14106, CVE-2017-14140, CVE-2017-14156, CVE-2017-14340, CVE-2017-14489, CVE-2017-14497, CVE-2017-1000111, CVE-2017-1000112, CVE-2017-1000251, CVE-2017-1000252, CVE-2017-1000370, CVE-2017-1000371, CVE-2017-1000380.
- More information:
Several vulnerabilities have been discovered in the Linux kernel that may lead to privilege escalation, denial of service or information leaks.
Andy Lutomirski discovered that KVM is prone to an incorrect debug exception (#DB) error occurring while emulating a syscall instruction. A process inside a guest can take advantage of this flaw for privilege escalation inside a guest.
Stefano Brivio of Red Hat discovered that the SCTP subsystem is prone to a data leak vulnerability due to an out-of-bounds read flaw, allowing to leak up to 100 uninitialized bytes to userspace.
Dmitry Vyukov of Google reported that the timerfd facility does not properly handle certain concurrent operations on a single file descriptor. This allows a local attacker to cause a denial of service or potentially execute arbitrary code.
Bo Zhang reported that the xfrm subsystem does not properly validate one of the parameters to a netlink message. Local users with the CAP_NET_ADMIN capability can use this to cause a denial of service or potentially to execute arbitrary code.
/ #866511 / XSA-229
Jan H. Schoenherr of Amazon discovered that when Linux is running in a Xen PV domain on an x86 system, it may incorrectly merge block I/O requests. A buggy or malicious guest may trigger this bug in dom0 or a PV driver domain, causing a denial of service or potentially execution of arbitrary code.
This issue can be mitigated by disabling merges on the underlying back-end block devices, e.g.:
echo 2> /sys/block/nvme0n1/queue/nomerges
Adrian Salido of Google reported a race condition in access to the
driver_overrideattribute for platform devices in sysfs. If unprivileged users are permitted to access this attribute, this might allow them to gain privileges.
Bo Zhang reported that the cfg80211 (wifi) subsystem does not properly validate the parameters to a netlink message. Local users with the CAP_NET_ADMIN capability (in any user namespace with a wifi device) can use this to cause a denial of service.
Jim Mattson of Google reported that the KVM implementation for Intel x86 processors did not correctly handle certain nested hypervisor configurations. A malicious guest (or nested guest in a suitable L1 hypervisor) could use this for denial of service.
Andrey Konovalov discovered that a user-triggerable division by zero in the tcp_disconnect() function could result in local denial of service.
Otto Ebeling reported that the move_pages() system call performed insufficient validation of the UIDs of the calling and target processes, resulting in a partial ASLR bypass. This made it easier for local users to exploit vulnerabilities in programs installed with the set-UID permission bit set.
sohu0106reported an information leak in the atyfb video driver. A local user with access to a framebuffer device handled by this driver could use this to obtain sensitive information.
Richard Wareing discovered that the XFS implementation allows the creation of files with the
realtimeflag on a filesystem with no realtime device, which can result in a crash (oops). A local user with access to an XFS filesystem that does not have a realtime device can use this for denial of service.
ChunYu Wang of Red Hat discovered that the iSCSI subsystem does not properly validate the length of a netlink message, leading to memory corruption. A local user with permission to manage iSCSI devices can use this for denial of service or possibly to execute arbitrary code.
Benjamin Poirier of SUSE reported that vnet headers are not properly handled within the tpacket_rcv() function in the raw packet (af_packet) feature. A local user with the CAP_NET_RAW capability can take advantage of this flaw to cause a denial of service (buffer overflow, and disk and memory corruption) or have other impact.
Andrey Konovalov of Google reported a race condition in the raw packet (af_packet) feature. Local users with the CAP_NET_RAW capability can use this for denial of service or possibly to execute arbitrary code.
Andrey Konovalov of Google reported a race condition flaw in the UDP Fragmentation Offload (UFO) code. A local user can use this flaw for denial of service or possibly to execute arbitrary code.
Armis Labs discovered that the Bluetooth subsystem does not properly validate L2CAP configuration responses, leading to a stack buffer overflow. This is one of several vulnerabilities dubbed
Blueborne. A nearby attacker can use this to cause a denial of service or possibly to execute arbitrary code on a system with Bluetooth enabled.
Jan H. Schoenherr of Amazon reported that the KVM implementation for Intel x86 processors did not correctly validate interrupt injection requests. A local user with permission to use KVM could use this for denial of service.
The Qualys Research Labs reported that a large argument or environment list can result in ASLR bypass for 32-bit PIE binaries.
The Qualys Research Labs reported that a large argument or environment list can result in a stack/heap clash for 32-bit PIE binaries.
Alexander Potapenko of Google reported a race condition in the ALSA (sound) timer driver, leading to an information leak. A local user with permission to access sound devices could use this to obtain sensitive information.
Debian disables unprivileged user namespaces by default, but if they are enabled (via the kernel.unprivileged_userns_clone sysctl) then CVE-2017-11600, CVE-2017-14497 and CVE-2017-1000111 can be exploited by any local user.
For the oldstable distribution (jessie), these problems have been fixed in version 3.16.43-2+deb8u5.
For the stable distribution (stretch), these problems have been fixed in version 4.9.30-2+deb9u5.
We recommend that you upgrade your linux packages.