Hi Andrew, > On 28 Mar 2020, at 23:14, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Fri, 27 Mar 2020 16:55:40 +0100 Simon Gander <simon@xxxxxxxxxx> wrote: >> When removing files containing extended attributes, the hfsplus driver >> may remove the wrong entries from the attributes b-tree, causing major >> filesystem damage and in some cases even kernel crashes. >> >> To remove a file, all its extended attributes have to be removed as well. >> The driver does this by looking up all keys in the attributes b-tree with >> the cnid of the file. Each of these entries then gets deleted using the >> key used for searching, which doesn't contain the attribute's name when it >> should. Since the key doesn't contain the name, the deletion routine will >> not find the correct entry and instead remove the one in front of it. If >> parent nodes have to be modified, these become corrupt as well. This causes >> invalid links and unsorted entries that not even macOS's fsck_hfs is able >> to fix. >> >> To fix this, modify the search key before an entry is deleted from the >> attributes b-tree by copying the found entry's key into the search key, >> therefore ensuring that the correct entry gets removed from the tree. > > This seems fairly important. Should it have a cc:stable? It is - that is why we are pushing it upstream. And yes, I think a cc:stable would be a good idea! Best regards, Anton -- Anton Altaparmakov <anton at tuxera.com> (replace at with @) Lead in File System Development, Tuxera Inc., http://www.tuxera.com/ Linux NTFS maintainer
