What’s Vulnerable › Vulnerabilities

CVE-2019-20812

• Severity: medium (CVSS 5.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2020-06-03 · updated 2026-06-17
• Weakness: CWE-400

Description

An issue was discovered in the Linux kernel before 5.4.7. The prb_calc_retire_blk_tmo() function in net/packet/af_packet.c can result in a denial of service (CPU consumption and soft lockup) in a certain failure case involving TPACKET_V3, aka CID-b43d1f9f7067.

Affected products

• Linux kernel: before 5.4.7 — fixed in 5.4.7

How to fix

Upgrade to a fixed version: Linux kernel 5.4.7. Check the vendor advisory for mitigations.

References

• http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.7
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b43d1f9f7067c6759b1051e8ecb84e82cef569fe
• https://www.oracle.com/security-alerts/cpuApr2021.html
• http://lists.opensuse.org/opensuse-security-announce/2020-06/msg00022.html
• http://lists.opensuse.org/opensuse-security-announce/2020-07/msg00008.html
• https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.4.7
• https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b43d1f9f7067c6759b1051e8ecb84e82cef569fe
• https://www.oracle.com/security-alerts/cpuApr2021.html

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