** Patch added: "0001-UBUNTU-SAUCE-overlayfs-handle-idmapped-mounts-in-ovl.patch" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2009065/+attachment/5651146/+files/0001-UBUNTU-SAUCE-overlayfs-handle-idmapped-mounts-in-ovl.patch
-- 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/2009065 Title: overlayfs mounts as R/O over idmapped mount Status in linux package in Ubuntu: Incomplete Bug description: Reproducer: create unprivileged LXC container $ lxc launch ubuntu:22.04 idmap-test $ lxc exec idmap-test bash check that root is idmapped by: $ cat /proc/self/mountinfo | grep idmap 780 675 8:1 /var/snap/lxd/common/lxd/storage- pools/default/containers/idmap-test/rootfs / rw,relatime,idmapped shared:323 master:319 - ext4 /dev/sda1 rw,discard,errors=remount-ro $ mkdir {work,upper,lower,ovl} $ mount -t overlay overlay -o lowerdir=lower,upperdir=upper,workdir=work ovl $ touch ovl/test touch: cannot touch 'ovl/test': Read-only file system The problem is in __vfs_removexattr_noperm() function that called from ovl_workdir_create(). In dmesg I can see an error: overlayfs: failed to create directory work/work (errno: 1); mounting read-only Reproducible on: # uname -a Linux ubuntu 5.19.0-32-generic #33~22.04.1-Ubuntu SMP PREEMPT_DYNAMIC Mon Jan 30 17:03:34 UTC 2 x86_64 x86_64 x86_64 GNU/Linux # cat /etc/os-release PRETTY_NAME="Ubuntu 22.04.1 LTS" Suspicious commit: https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/jammy/commit/fs/overlayfs/overlayfs.h?h=Ubuntu-hwe-5.19-5.19.0-32.33_22.04.1&id=3418435738af5730918fafbdfe2905a98ce2ef05 Chunk: + inode_lock(inode); + err = __vfs_setxattr_noperm(&init_user_ns, dentry, name, value, size, flags); + inode_unlock(inode); should be: + inode_lock(inode); + err = __vfs_setxattr_noperm(ovl_upper_mnt_userns(ofs), dentry, name, value, size, flags); + inode_unlock(inode); I'll send a patch soon. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2009065/+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
