Dmitry Vyukov wrote: > > syzbot is reporting various bugs which involve /dev/loopX. > > Two of them > > > > INFO: rcu detected stall in lo_ioctl > > > > https://syzkaller.appspot.com/bug?id=7b49fb610af9cca78c24e9f796f2e8b0d5573997 > > > > general protection fault in lo_ioctl (2) > > > > https://syzkaller.appspot.com/bug?id=f3cfe26e785d85f9ee259f385515291d21bd80a3 > > /\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ > > Now there is a repro for this one. I've pushed it to kernel mailing lists: > > https://groups.google.com/d/msg/syzkaller-bugs/c8KUcTAzTvA/3o_7g6-tAwAJ
OK, thanks. But among loop related reports, this will be a dup of "INFO: rcu detected stall in blkdev_ioctl" which already has C reproducer. Should we merge them? INFO: rcu detected stall in blkdev_ioctl https://syzkaller.appspot.com/bug?id=1f7b710f4110f225aed1f4263ec2b98b8dbd472e general protection fault in lo_ioctl (2) https://syzkaller.appspot.com/bug?id=f3cfe26e785d85f9ee259f385515291d21bd80a3 #syz dup: INFO: rcu detected stall in blkdev_ioctl INFO: rcu detected stall in lo_compat_ioctl https://syzkaller.appspot.com/bug?id=6299555c4e252b53f7a2ae2b8216cc9456c56ac0 #syz dup: INFO: rcu detected stall in blkdev_ioctl INFO: rcu detected stall in lo_ioctl https://syzkaller.appspot.com/bug?id=7b49fb610af9cca78c24e9f796f2e8b0d5573997 #syz dup: INFO: rcu detected stall in blkdev_ioctl INFO: task hung in lo_ioctl https://syzkaller.appspot.com/bug?id=608144371e7fc2cb6285b9ed871fb1eb817a61ce INFO: task hung in lo_open (2) https://syzkaller.appspot.com/bug?id=1f93b57f496d969efb9fb24167f6f9de5ee068fd possible deadlock in blkdev_reread_part https://syzkaller.appspot.com/bug?id=bf154052f0eea4bc7712499e4569505907d15889 INFO: task hung in loop_control_ioctl https://syzkaller.appspot.com/bug?id=61fe32c77ea00412c5149bd34649a65b7f672b5e WARNING in sysfs_remove_group https://syzkaller.appspot.com/bug?id=3f86c0edf75c86d2633aeb9dd69eccc70bc7e90b > > > suggest that loop module is not thread safe. The former suggests that > > l->lo_backing_file is forming circular loop and the latter suggests that > > l->lo_backing_file became NULL.
