On Tue, Jan 24, 2017 at 09:37:18PM -0000, Jonathan Calmels wrote: > Interesting, I tried to reproduce with a Debian strech 4.8.0-2-amd64 > (Debian 4.8.15-2) and 4.9.0-1-amd64 (Debian 4.9.2-2) and didn't hit the > error.
Odd. The commit responsible for this should be 036d523641c6 "vfs: Don't create inodes with a uid or gid unknown to the vfs" which did go into 4.8. I'll have to take another look. > This seems to be specific to tmpfs though, touching the file anywhere > else yields the nobody:nogroup mapping. It would happen for any filesystem which was mounted from within the user namespace. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1659087 Title: open(2) returns EOVERFLOW within tmpfs+userns Status in linux package in Ubuntu: Confirmed Bug description: On Ubuntu 4.4.0-59.80-generic 4.4.35, open(2) returns EOVERFLOW when creating a file in tmpfs with user namespace enabled. This issue wasn't present in 4.4.0-47 and has probably been introduced by https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1634964 Step to reproduce: $ unshare -r -U -m /bin/bash # mount -t tmpfs tmpfs /mnt # echo $$ 2354 In another terminal: $ sudo nsenter -t 2354 -m # touch /mnt/foo touch: cannot touch '/mnt/foo': Value too large for defined data type Note that we are not joining the user namespace when creating the file but we would expect `touch' to succeed and create the file with an inode set to INVALID_UID/GID (i.e. nobody:nogroup) within the mount namespace. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1659087/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
