MGASA-2020-0158 - Updated kernel-linus packages fix security vulnerabilities

Publication date: 03 Apr 2020
URL: https://advisories.mageia.org/MGASA-2020-0158.html
Type: security
Affected Mageia releases: 7
CVE: CVE-2019-19768,
     CVE-2019-19769,
     CVE-2020-2732,
     CVE-2020-8647,
     CVE-2020-8648,
     CVE-2020-8649,
     CVE-2020-8835,
     CVE-2020-9383,
     CVE-2020-9391

This update is based on upstream 5.5.15 and fixes atleast the following
security vulnerabilities:

In the Linux kernel 5.4.0-rc2, there is a use-after-free (read) in the
__blk_add_trace function in kernel/trace/blktrace.c (which is used to
fill out a blk_io_trace structure and place it in a per-cpu sub-buffer)
(CVE-2019-19768).

In the Linux kernel 5.3.10, there is a use-after-free (read) in the
perf_trace_lock_acquire function (related to include/trace/events/lock.h)
(CVE-2019-19769).

A flaw was found in the way KVM hypervisor handled instruction emulation
for the L2 guest when nested(=1) virtualization is enabled. In the
instruction emulation, the L2 guest could trick the L0 hypervisor into
accessing sensitive bits of the L1 hypervisor. An L2 guest could use this
flaw to potentially access information of the L1 hypervisor
(CVE-2020-2732).

There is a use-after-free vulnerability in the Linux kernel through 5.5.2
in the vc_do_resize function in drivers/tty/vt/vt.c (CVE-2020-8647).

There is a use-after-free vulnerability in the Linux kernel through 5.5.2
in the n_tty_receive_buf_common function in drivers/tty/n_tty.c
(CVE-2020-8648).

Manfred Paul discovered that the bpf verifier in the Linux kernel did not
properly calculate register bounds for certain operations. A local attacker
could use this to expose sensitive information (kernel memory) or gain
administrative privileges (CVE-2020-8835).

There is a use-after-free vulnerability in the Linux kernel through 5.5.2
in the vgacon_invert_region function in drivers/video/console/vgacon.c. 
(CVE-2020-8649).

An issue was discovered in the Linux kernel through 5.5.6. set_fdc in
drivers/block/floppy.c leads to a wait_til_ready out-of-bounds read
because the FDC index is not checked for errors before assigning it,
aka CID-2e90ca68b0d2 (CVE-2020-9383).

An issue was discovered in the Linux kernel 5.4 and 5.5 through 5.5.6
on the AArch64 architecture. It ignores the top byte in the address
passed to the brk system call, potentially moving the memory break
downwards when the application expects it to move upwards, aka CID-
dcde237319e6. This has been observed to cause heap corruption with
the GNU C Library malloc implementation (CVE-2020-9391).

Security fixes and hardenings to the mac00211 layer to prevent leaking keys
and frames.

For other upstream fixes in this update, see the referenced changelogs.

References:
- https://bugs.mageia.org/show_bug.cgi?id=26426
- https://kernelnewbies.org/Linux_5.5
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.1
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.2
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.3
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.4
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.5
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.6
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.7
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.8
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.9
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.10
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.11
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.12
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.13
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.14
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.5.15
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19768
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-19769
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-2732
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8647
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8648
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8649
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-8835
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-9383
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-9391

SRPMS:
- 7/core/kernel-5.5.15-1.mga7