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. CREATE(Triage):(User=admin) CVE-2019-20812 (https://nvd.nist.gov/vuln/detail/CVE-2019-20812)