An issue was discovered in __split_huge_pmd in mm/huge_memory.c in the Linux kernel before 5.7.5. The copy-on-write implementation can grant unintended write access because of a race condition in a THP mapcount check. Reference: https://bugs.chromium.org/p/project-zero/issues/detail?id=2045 Upstream patch: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=c444eb564fb16645c172d550359cb3d75fe8a040
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1903245]
This was fixed for Fedora with the 5.7.5 stable kernel updates.
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:4140 https://access.redhat.com/errata/RHSA-2021:4140
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2021:4356 https://access.redhat.com/errata/RHSA-2021:4356
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2020-29368
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.2 Extended Update Support Via RHSA-2022:5224 https://access.redhat.com/errata/RHSA-2022:5224
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.2 Extended Update Support Via RHSA-2022:5220 https://access.redhat.com/errata/RHSA-2022:5220
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Extended Update Support Via RHSA-2022:5626 https://access.redhat.com/errata/RHSA-2022:5626
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Extended Update Support Via RHSA-2022:5633 https://access.redhat.com/errata/RHSA-2022:5633