{"id":"RLSA-2021:3088","summary":"Important: kernel-rt security and bug fix update","details":"The kernel-rt packages provide the Real Time Linux Kernel, which enables fine-tuning for systems with extremely high determinism requirements.\n\nSecurity Fix(es):\n\n* kernel: race condition in net/can/bcm.c leads to local privilege escalation (CVE-2021-3609)\n\n* kernel: Improper handling of VM_IO|VM_PFNMAP vmas in KVM can bypass RO checks (CVE-2021-22543)\n\n* kernel: out-of-bounds write in xt_compat_target_from_user() in net/netfilter/x_tables.c (CVE-2021-22555)\n\nFor more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.\n\nBug Fix(es):\n\n* kernel-rt: update RT source tree to the Rocky Linux-8.4.z source tree (BZ#1985050)\n\n* kernel-rt: Merge mm/memcg: Fix kmem_cache_alloc() performance regression (BZ#1987102)","modified":"2026-02-05T11:30:03.691749Z","published":"2021-08-10T12:10:45Z","upstream":["CVE-2021-22543","CVE-2021-22555","CVE-2021-3609"],"references":[{"type":"ADVISORY","url":"https://errata.rockylinux.org/RLSA-2021:3088"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1965461"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1971651"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=1980101"}],"affected":[{"package":{"name":"kernel-rt","ecosystem":"Rocky Linux:8","purl":"pkg:rpm/rocky-linux/kernel-rt?distro=rocky-linux-8-4-legacy&epoch=0"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:4.18.0-305.12.1.rt7.84.el8_4"}],"database_specific":{"yum_repository":"RT"}}],"database_specific":{"source":"https://storage.googleapis.com/resf-osv-data/RLSA-2021:3088.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}],"credits":[{"name":"Rocky Enterprise Software Foundation"},{"name":"Red Hat"}]}