Updated kernel packages fix security vulnerabilitiesPublication date: 27 Oct 2018
Affected Mageia releases : 6
CVE: CVE-2018-7755 , CVE-2018-14633 , CVE-2018-15471 , CVE-2018-18281 , CVE-2018-18445
This kernel update is based on the upstream 4.14.78 and fixes at least the following security issues: An issue was discovered in the fd_locked_ioctl function in drivers/block/floppy.c in the Linux kernel through 4.15.7. The floppy driver will copy a kernel pointer to user memory in response to the FDGETPRM ioctl. An attacker can send the FDGETPRM ioctl and use the obtained kernel pointer to discover the location of kernel code and data and bypass kernel security protections such as KASLR (CVE-2018-7755). A security flaw was found in the chap_server_compute_md5() function in the ISCSI target code in the Linux kernel in a way an authentication request from an ISCSI initiator is processed. An unauthenticated remote attacker can cause a stack buffer overflow and smash up to 17 bytes of the stack. The attack requires the iSCSI target to be enabled on the victim host. Depending on how the target's code was built (i.e. depending on a compiler, compile flags and hardware architecture) an attack may lead to a system crash and thus to a denial-of-service or possibly to a non-authorized access to data exported by an iSCSI target. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is highly unlikely (CVE-2018-14633). An issue was discovered in xenvif_set_hash_mapping in drivers/net/xen-netback/hash.c in the Linux kernel through 4.18.1, as used in Xen through 4.11.x and other products. The Linux netback driver allows frontends to control mapping of requests to request queues. When processing a request to set or change this mapping, some input validation (e.g., for an integer overflow) was missing or flawed, leading to OOB access in hash handling. A malicious or buggy frontend may cause the (usually privileged) backend to make out of bounds memory accesses, potentially resulting in one or more of privilege escalation, Denial of Service (DoS), or information leaks (CVE-2018-15471). Since Linux kernel version 3.2, the mremap() syscall performs TLB flushes after dropping pagetable locks. If a syscall such as ftruncate() removes entries from the pagetables of a task that is in the middle of mremap(), a stale TLB entry can remain for a short time that permits access to a physical page after it has been released back to the page allocator and reused (CVE-2018-18281). In the Linux kernel 4.14.x, 4.15.x, 4.16.x, 4.17.x, and 4.18.x before 4.18.13, faulty computation of numeric bounds in the BPF verifier permits out-of-bounds memory accesses because adjust_scalar_min_max_vals in kernel/bpf/verifier.c mishandles 32-bit right shifts (CVE-2018-18445). Other fixes in this update: * WireGuard has been updated 0.0.20181018 For other uptstream fixes in this update, see the referenced changelogs.