Attaching test script to reproduce the bug, adapted from the reproducer for bug 1850994. Requires the bindfs package.
** Description changed: As reported by Jann Horn on bug 1850994, unprivileged overlayfs mounting - fails in disco/eoan due to SB_I_NOSUID and SB_I_USERNS_VISIBLE. + can fail in disco/eoan due to SB_I_NOSUID and SB_I_USERNS_VISIBLE. overlayfs sets SB_I_NOSUID for unprivileged mounts, which causes - mount_too_revealing() to bail out as it sees SB_I_USERNS_VISIBLE as - being set. + mount_too_revealing() to see SB_I_USERNS_VISIBLE as being set. This + leads to performing additional, unnecessary checks which may fail. ** Attachment added: "test.sh" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1851677/+attachment/5303526/+files/test.sh ** Changed in: linux (Ubuntu Disco) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Disco) Status: New => In Progress ** Changed in: linux (Ubuntu Disco) Assignee: (unassigned) => Seth Forshee (sforshee) ** Changed in: linux (Ubuntu Eoan) Importance: Undecided => Medium ** Changed in: linux (Ubuntu Eoan) Status: New => In Progress ** Changed in: linux (Ubuntu Eoan) Assignee: (unassigned) => Seth Forshee (sforshee) -- 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/1851677 Title: s_iflags overlap prevents unprivileged overlayfs mounts Status in linux package in Ubuntu: In Progress Status in linux source package in Disco: In Progress Status in linux source package in Eoan: In Progress Bug description: As reported by Jann Horn on bug 1850994, unprivileged overlayfs mounting can fail in disco/eoan due to SB_I_NOSUID and SB_I_USERNS_VISIBLE. overlayfs sets SB_I_NOSUID for unprivileged mounts, which causes mount_too_revealing() to see SB_I_USERNS_VISIBLE as being set. This leads to performing additional, unnecessary checks which may fail. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1851677/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : [email protected] Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
