Date: Mon, 15 Jun 2020 19:02:51 +0200 From: Jann Horn <jannh@...gle.com> To: John Haxby <john.haxby@...cle.com> Cc: oss-security@...ts.openwall.com, "Jason A. Donenfeld" <Jason@...c4.com>, linux-security-module <linux-security-module@...r.kernel.org>, linux-acpi@...r.kernel.org, Matthew Garrett <mjg59@...f.ucam.org>, Kernel Hardening <kernel-hardening@...ts.openwall.com>, Ubuntu Kernel Team <kernel-team@...ts.ubuntu.com> Subject: Re: lockdown bypass on mainline kernel for loading unsigned modules On Mon, Jun 15, 2020 at 6:24 PM John Haxby <john.haxby@...cle.com> wrote: > > On 15 Jun 2020, at 11:26, Jason A. Donenfeld <Jason@...c4.com> wrote: > > Yesterday, I found a lockdown bypass in Ubuntu 18.04's kernel using > > ACPI table tricks via the efi ssdt variable . Today I found another > > one that's a bit easier to exploit and appears to be unpatched on > > mainline, using acpi_configfs to inject an ACPI table. The tricks are > > basically the same as the first one, but this one appears to be > > unpatched, at least on my test machine. Explanation is in the header > > of the PoC: > > > > https://git.zx2c4.com/american-unsigned-language/tree/american-unsigned-language-2.sh > > > > I need to get some sleep, but if nobody posts a patch in the > > meanwhile, I'll try to post a fix tomorrow. > > > > Jason > > > >  https://www.openwall.com/lists/oss-security/2020/06/14/1 > > > This looks CVE-worthy. Are you going to ask for a CVE for it? Does it really make sense to dole out CVEs for individual lockdown bypasses when various areas of the kernel (such as filesystems and BPF) don't see root->kernel privilege escalation issues as a problem? It's not like applying the fix for this one issue is going to make systems meaningfully safer.
Powered by blists - more mailing lists
Please check out the Open Source Software Security Wiki, which is counterpart to this mailing list.
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.