A user with permissions to mount and unmount a crafted ext4 file system, via any transport mechanism (local, USB, ISCSI) can lead to a use-after-free when attempting to delete a directory after the disk has been umounted. This can lead to possible memory corruption and privilege escalation. External Reference: https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19447 https://bugzilla.kernel.org/show_bug.cgi?id=205433
Created kernel tracking bugs for this issue: Affects: fedora-all [bug 1781680]
Mitigation: Ext4 filesytems are built into the kernel so it is not possible to prevent the kernel module from loading. However, this flaw can be prevented by disallowing mounting of untrusted filesystems. As mounting is a privileged operation, (except for device hotplug) removing the ability for mounting and unmounting will prevent this flaw from being exploited.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:2104 https://access.redhat.com/errata/RHSA-2020:2104
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-2019-19447
This was fixed for Fedora in the 5.4.4 stable kernel update.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:4062 https://access.redhat.com/errata/RHSA-2020:4062
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:4060 https://access.redhat.com/errata/RHSA-2020:4060
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:4431 https://access.redhat.com/errata/RHSA-2020:4431
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:4609 https://access.redhat.com/errata/RHSA-2020:4609
This issue has been addressed in the following products: Red Hat Enterprise Linux 7.7 Extended Update Support Via RHSA-2020:5206 https://access.redhat.com/errata/RHSA-2020:5206
This issue has been addressed in the following products: Red Hat Enterprise Linux 7.4 Advanced Update Support Red Hat Enterprise Linux 7.4 Update Services for SAP Solutions Red Hat Enterprise Linux 7.4 Telco Extended Update Support Via RHSA-2020:5430 https://access.redhat.com/errata/RHSA-2020:5430
This issue has been addressed in the following products: Red Hat Enterprise Linux 7.6 Extended Update Support Via RHSA-2020:5656 https://access.redhat.com/errata/RHSA-2020:5656