Hello! On Thu, Aug 4, 2011 at 5:09 PM, Luiz Augusto von Dentz <luiz.dentz@xxxxxxxxx> wrote: > Hi, > > On Thu, Aug 4, 2011 at 4:45 PM, Slawomir Bochenski <lkslawek@xxxxxxxxx> wrote: >> This patch changes the way the symbolic links are treated by FTP, making code a >> bit simpler and FTP more intuitive. >> >> Previously symlinks were supposed to be disallowed unless the -l option was >> used, and with that option, only symlinks present directly inside root folder >> were followed. This did not work for file links, as fstat() check on open()-ed >> won't result in S_IFLNK set, so symbolic links to files were followed >> regardless to options. >> >> Now links inside root folder are always allowed. Without -l (--symlinks) >> option, following them is only allowed when the resulting real path is still >> inside the given root directory. When -l is given, all symlinks are followed. > > This only resolves the security problem of following the symbolic > links, but what we do with the clients not being able to see it is a > link since it is not part of the folder listing, this can be > inconsistent since the user can try to remove the file, which is what > we will be stating, but end up removing only the link (see remove > manpage), in the other hand if we remove both the user still have no > clue that other files maybe affected. There is also no possibility to read link itself or - what is more important, to put new one. Thus from the client's perspective this is just a regular file and when it deletes it, link should be the only thing deleted. And this operation would work as expected. I think we can call this side-effect a feature ;). As the obexd admin is the only one who can create links in obexd he can even use this for his own evil needs, like pretending that something can be deleted (despite he fact that he could do the same with hard links). And after all "rm symlink" removes the link. Maybe one day someone will find adding links support to OBEX specs useful and then we will be able to do this really good. BR, Slawomir Bochenski -- To unsubscribe from this list: send the line "unsubscribe linux-bluetooth" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
