CVE-2019-20934

Description

An issue was discovered in the Linux kernel before 5.2.6. On NUMA systems, the Linux fair scheduler has a use-after-free in show_numa_stats() because NUMA fault statistics are inappropriately freed, aka CID-16d51a590a8c.

CVSS Metrics

• v3.1•MEDIUM•Score: 5.3CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:H
• v2.0•MEDIUM•Score: 5.4AV:L/AC:M/Au:N/C:P/I:N/A:C

EPSS Trends

Current EPSS score: 0.04%• Percentile: 12%

Techniques & Countermeasures

• CWE-416•Use After Free

  The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

• linux•linux_kernel

  ≥ 4.19, < 4.19.64 | ≥ 5.2, ≤ 5.2.17 | 5.3:rc1

References (3)

• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.2.6
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=16d51a590a8ce3befb1308e0e7ab77f3b661af33
• https://bugs.chromium.org/p/project-zero/issues/detail?id=1913