Entreprise française de cybersécurité depuis 2004
☎ 03 60 47 09 81 - info@securiteinfo.com
☎ 03 60 47 09 81 - info@securiteinfo.com
In the Linux kernel, the following vulnerability has been resolved:clone_private_mnt(): make sure that caller has CAP_SYS_ADMIN in the right usernsWhat we want is to verify there is that clone won't expose somethinghidden by a mount we wouldn't be able to undo. "Wouldn't be able to undo"may be a result of MNT_LOCKED on a child, but it may also come fromlacking admin rights in the userns of the namespace mount belongs to.clone_private_mnt() checks the former, but not the latter.There's a number of rather confusing CAP_SYS_ADMIN checks in varioususerns during the mount, especially with the new mount API; they servedifferent purposes and in case of clone_private_mnt() they usually,but not always end up covering the missing check mentioned above.
No PoCs from references.
- https://github.com/w4zu/Debian_security