Updated kernel-linus packages fixes security vulnerabilitiesPublication date: 16 May 2019
Affected Mageia releases : 6
CVE: CVE-2018-12126 , CVE-2018-12127 , CVE-2018-12130 , CVE-2018-1000026 , CVE-2019-3882 , CVE-2019-7308 , CVE-2019-9213 , CVE-2019-11091 , CVE-2019-11486 , CVE-2019-11599
This kernel update provides the upstream 4.14.119 that adds the kernel side mitigations for the Microarchitectural Data Sampling (MDS, also called ZombieLoad attack) vulnerabilities in Intel processors that can allow attackers to retrieve data being processed inside a CPU. To complete the mitigations new microcode is also needed, either by installing the microcode-0.20190514-1.mga6 package, or get an updated bios / uefi firmware from the motherboard vendor. The fixed / mitigated issues are: Modern Intel microprocessors implement hardware-level micro-optimizations to improve the performance of writing data back to CPU caches. The write operation is split into STA (STore Address) and STD (STore Data) sub-operations. These sub-operations allow the processor to hand-off address generation logic into these sub-operations for optimized writes. Both of these sub-operations write to a shared distributed processor structure called the 'processor store buffer'. As a result, an unprivileged attacker could use this flaw to read private data resident within the CPU's processor store buffer. (CVE-2018-12126) Microprocessors use a ‘load port’ subcomponent to perform load operations from memory or IO. During a load operation, the load port receives data from the memory or IO subsystem and then provides the data to the CPU registers and operations in the CPU’s pipelines. Stale load operations results are stored in the 'load port' table until overwritten by newer operations. Certain load-port operations triggered by an attacker can be used to reveal data about previous stale requests leaking data back to the attacker via a timing side-channel. (CVE-2018-12127) A flaw was found in the implementation of the "fill buffer", a mechanism used by modern CPUs when a cache-miss is made on L1 CPU cache. If an attacker can generate a load operation that would create a page fault, the execution will continue speculatively with incorrect data from the fill buffer while the data is fetched from higher level caches. This response time can be measured to infer data in the fill buffer. (CVE-2018-12130) Uncacheable memory on some microprocessors utilizing speculative execution may allow an authenticated user to potentially enable information disclosure via a side channel with local access. (CVE-2019-11091) It also fixes at least the following security issues: Linux Linux kernel version at least v4.8 onwards, probably well before contains a Insufficient input validation vulnerability in bnx2x network card driver that can result in DoS: Network card firmware assertion takes card off-line. This attack appear to be exploitable via An attacker on a must pass a very large, specially crafted packet to the bnx2x card. This can be done from an untrusted guest VM (CVE-2018-1000026) A flaw was found in the Linux kernel's vfio interface implementation that permits violation of the user's locked memory limit. If a device is bound to a vfio driver, such as vfio-pci, and the local attacker is administratively granted ownership of the device, it may cause a system memory exhaustion and thus a denial of service (DoS) (CVE-2019-3882). kernel/bpf/verifier.c in the Linux kernel before 4.20.6 performs undesirable out-of-bounds speculation on pointer arithmetic in various cases, including cases of different branches with different state or limits to sanitize, leading to side-channel attacks (CVE-2019-7308). In the Linux kernel before 4.20.14, expand_downwards in mm/mmap.c lacks a check for the mmap minimum address, which makes it easier for attackers to exploit kernel NULL pointer dereferences on non-SMAP platforms. This is related to a capability check for the wrong task (CVE-2019-9213). The Siemens R3964 line discipline driver in drivers/tty/n_r3964.c in the Linux kernel before 5.0.8 has multiple race conditions (CVE-2019-11486). The coredump implementation in the Linux kernel before 5.0.10 does not use locking or other mechanisms to prevent vma layout or vma flags changes while it runs, which allows local users to obtain sensitive information, cause a denial of service, or possibly have unspecified other impact by triggering a race condition with mmget_not_zero or get_task_mm calls (CVE-2019-11599). It also fixes signal handling issues causing powertop to crash and some tracing tools to fail on execve tests. For other uptstream fixes in this update, see the referenced changelogs.