On Tue, Dec 28, 2010 at 5:06 PM, Olaf van der Spek <olafvdspek@xxxxxxxxx> wrote: > On Tue, Dec 28, 2010 at 11:00 PM, Greg Freemyer <greg.freemyer@xxxxxxxxx> wrote: >> create temp file >> write out new data >> delete old file >> rename temp file to primary name >> === >> >> If so there is still a little window of vulnerability where the whole >> file can be lost. (Or at least only the temp file is present). > > Delete isn't used, rename will overwrite the old file. So it's safe. > Meta-data is probably lost, file owner is certainly lost. > > Olaf So ACLs are lost? That seems like a potentially bigger issue than loosing the owner/group info. And I assume if the owner changes, then the new owner has privileges to modify ACLs he didn't have previously. So if I want to instigate a simple denial of service in a multi-user environment, I edit a few key docs that I have privileges to edit. By doing so I take ownership. As owner I change the permissions and ACLs so that no one but me can access them. Seems like a security hole to me. Greg -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
