On Tue, Mar 10, 2015 at 10:22 AM, Konstantin Khlebnikov <khlebnikov@xxxxxxxxxxxxxx> wrote: > Historically XFS project id doesn't have any permission control: file owner > is able to set any project id. Later they was sealed with user-namespace: > XFS allows to change it only from init user-ns. That works fine for isolated > containers or if user doesn't have direct access to the filesystem (NFS/FTP). > > This patch adds sysctl fs.protected_projects which makes changing project id > privileged operation which requires CAP_SYS_RESOURCE in current user-namespace. > Thus there are two levels of protection: project id mapping in user-ns defines > set of permitted projects and capability protects operations within this set. If I understand this right, this doesn't work. If I lack CAP_SYS_RESOURCE but I have two projids mapped, then I can create a new userns, map both projids, and get CAP_SYS_RESOURCE. --Andy -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
