Hi Miklos, I think we've found a "regression" that has crept in due to this patch: commit a09f99eddef44035ec764075a37bace8181bec38 Author: Miklos Szeredi <mszeredi@xxxxxxxxxx> Date: Sat Oct 1 07:32:32 2016 +0200 fuse: fix killing s[ug]id in setattr Basically, the pjdfstests set the ownership of a file to 06555, and then chowns it (as root) to a new uid/gid. Prior to the patch above, fuse would send down a setattr with both the uid/gid change and a new mode. Now, it just sends down the uid/gid change. Technically this is NOTABUG, since POSIX doesn't _require_ that we clear these bits for a privileged process, but Linux (wisely) has done that and I think we don't want to change that behavior here. So, the issue I think is the use of should_remove_suid, which will always return 0 when the process has CAP_FSETID. That's appropriate (I think) for write/truncate, but not chown, where we want to ignore that. Thoughts on the right fix here? A simple fix would be to add an "override" bool to should_remove_suid, but maybe there's some more elegant way to do it? -- Jeff Layton <jlayton@xxxxxxxxxx> -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
