SB2019091311 - Information disclosure in Linux kernel

Description

This security bulletin contains information about 1 vulnerability.

1) Information disclosure (CVE-ID: CVE-2019-15031)

CWE-ID: CWE-200 - Exposure of sensitive information to an unauthorized actor

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local authenticated user to #BASIC_IMPACT#.

In the Linux kernel through 5.2.14 on the powerpc platform, a local user can read vector registers of other users' processes via an interrupt. To exploit the venerability, a local user starts a transaction (via the hardware transactional memory instruction tbegin) and then accesses vector registers. At some point, the vector registers will be corrupted with the values from a different local Linux process, because MSR_TM_ACTIVE is misused in arch/powerpc/kernel/process.c.

Remediation

Install update from vendor's website.

References

• https://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.73
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2.15
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.3