Use-after-free in Linux kernel - CVE-2019-11811

Vulnerability identifier: #VU19138

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-2019-11811

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local usre to elevate privileges on the system.

The vulnerability exists due to a use-after-free error when trying to read data from /proc/ioports after the ipmi_si module is removed (related to drivers/char/ipmi/ipmi_si_intf.c, drivers/char/ipmi/ipmi_si_mem_io.c, and drivers/char/ipmi/ipmi_si_port_io.c). A local user can exploit this issue to elevate privileges on the system.

Linux kernel
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power 9
Red Hat Enterprise Linux for IBM System z (Structure A)
Red Hat Enterprise Linux Server - AUS
Red Hat Enterprise Linux Server - TUS
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, big endian - Extended Update Support
Red Hat Enterprise Linux EUS Compute Node
Red Hat Enterprise Linux for Power, little endian - Extended Update Support

MRG Realtime
kernel (Red Hat package)
kernel-rt (Red Hat package)
Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions
Red Hat Enterprise Linux Server for x86_64 - Update Services for SAP Solutions
kernel-alt (Red Hat package)

Install updates from vendor's website.

Linux kernel - update to 5.0.4
kernel (Red Hat package) - addressed in versions 3.10.0-693.61.1.el7, 3.10.0-862.46.1.el7
kernel-rt (Red Hat package) - update to 3.10.0-693.61.1.rt56.656.el6rt
kernel-alt (Red Hat package) - update to 4.14.0-115.26.1.el7a

• http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00071.html
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.0.4
• https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=401e7e88d4ef80188ffa07095ac00456f901b8c4
• https://github.com/torvalds/linux/commit/401e7e88d4ef80188ffa07095ac00456f901b8c4

• Red Hat update for kernel-rt
• Red Hat update for kernel
• Red Hat update for kernel
• Red Hat Enterprise Linux 7 update for kernel-alt