Trying the fsuid/fsgid workaround, I came across another oddity: $ id -u 1000 $ id -g 1000 $ unshare -r -U -m /bin/bash # mount -t tmpfs tmpfs /mnt # chmod 555 /mnt # ls -ldn /mnt dr-xr-xr-x 2 0 0 40 Jan 26 14:15 /mnt # echo $$ 2354
In another terminal: $ sudo nsenter -G 1000 -S 1000 -t 2354 -m $ ls -ldn /mnt dr-xr-xr-x 2 1000 1000 40 Jan 26 14:10 /mnt $ touch /mnt/foo touch: cannot touch '/mnt/foo': Permission denied Even though I'm supposed to be root in the context of the user namespace, I can't create the file because I'm lacking the write permission on the mount directory. In this case, setting the fsuid/fsgid is not sufficient, I have to join the user namespace if I want the permissions to be resolved correctly. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1659087 Title: open(2) returns EOVERFLOW within tmpfs+userns To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1659087/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
