Use-after-free in Linux kernel - CVE-2019-19807

Vulnerability identifier: #VU30551

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2019-19807

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local authenticated user to execute arbitrary code.

In the Linux kernel before 5.3.11, sound/core/timer.c has a use-after-free caused by erroneous code refactoring, aka CID-e7af6307a8a5. This is related to snd_timer_open and snd_timer_close_locked. The timeri variable was originally intended to be for a newly created timer instance, but was used for a different purpose after refactoring.

Linux kernel
Red Hat Enterprise Linux Workstation
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for x86_64
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support
Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support
Red Hat Enterprise Linux for x86_64 - Extended Update Support
Red Hat Enterprise Linux for IBM z Systems - Extended Update Support
Red Hat Enterprise Linux for Power, little endian - Extended Update Support
Red Hat Enterprise Linux for ARM 64 - Extended Update Support
Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support
Red Hat Enterprise Linux Server - TUS
Red Hat Enterprise Linux Server - AUS
Ubuntu
linux-kvm (Ubuntu package)
linux-snapdragon (Ubuntu package)
linux-hwe (Ubuntu package)
linux-gcp (Ubuntu package)
linux-azure (Ubuntu package)
linux (Ubuntu package)
linux-raspi2 (Ubuntu package)
linux-aws (Ubuntu package)
linux-oracle (Ubuntu package)
linux-oem (Ubuntu package)
linux-gke-4.15 (Ubuntu package)
linux-aws-hwe (Ubuntu package)
kernel (Red Hat package)
kernel-rt (Red Hat package)

Install update from vendor's website.

Linux kernel - update to 5.3.11
linux-kvm (Ubuntu package) - update to 4.15.0-1052.52
linux-snapdragon (Ubuntu package) - update to 4.15.0-1070.77
linux-hwe (Ubuntu package) - update to 4.15.0-74.83~16.04.1
linux-gcp (Ubuntu package) - update to 4.15.0-1052.56
linux-azure (Ubuntu package) - update to 4.15.0-1066.71
linux (Ubuntu package) - update to 4.15.0-74.84
linux-raspi2 (Ubuntu package) - update to 4.15.0-1053.57
linux-aws (Ubuntu package) - update to 4.15.0-1057.59
linux-oracle (Ubuntu package) - addressed in versions 4.15.0-1031.34~16.04.1, 4.15.0-1031.34
linux-oem (Ubuntu package) - update to 4.15.0-1066.76
linux-gke-4.15 (Ubuntu package) - update to 4.15.0-1050.53
linux-aws-hwe (Ubuntu package) - update to 4.15.0-1057.59~16.04.1
kernel (Red Hat package) - addressed in versions 3.10.0-1160.el7, 4.18.0-147.24.2.el8_1, 4.18.0-193.13.2.el8_2
kernel-rt (Red Hat package) - addressed in versions 3.10.0-1160.rt56.1131.el7, 4.18.0-193.13.2.rt13.65.el8_2

• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3.11
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=e7af6307a8a54f0b873960b32b6a644f2d0fbd97
• https://github.com/torvalds/linux/commit/e7af6307a8a54f0b873960b32b6a644f2d0fbd97
• https://security.netapp.com/advisory/ntap-20200103-0001/
• https://usn.ubuntu.com/4225-1/
• https://usn.ubuntu.com/4227-1/
• https://usn.ubuntu.com/4227-2/

• Multiple vulnerabilities in Linux kernel
• Red Hat Enterprise Linux 8 update for kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Red Hat Enterprise Linux 8.1 Extended Update Support update for kernel
• Red Hat Enterprise Linux 7 update for kernel-rt
• Red Hat Enterprise Linux 7 update for kernel
• Ubuntu update for linux, linux-aws, linux-aws-hwe and more