With additional data it is basically a bug in either the mount syscall, the generic_make_request_checks, or dm.c. Basically device-mapper is set up in two stages, the initial device creation and the table load. Somehwere around v4.1 things were changed to defer setting the make- request function of the device (queue) to when the mapping table gets loaded.
One can create such a intermediate setup using "dmsetup create -n <name>". Then a "mount /dev/dm-?" triggers the bug. Since generic_make_request_checks has a check for device->queue == NULL but not for device->queue->make_request_fn == NULL. Interestingly neither blkid nor dd would trigger this. Likely because they first check the size which is still 0 at that time. Only mount seems to go off and try to read superblock info regardless. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1860231 Title: 5.4.0-11 crash on cryptsetup open To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1860231/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
