Date: Tue, 20 Feb 2018 13:29:02 +0300 From: Alexander Popov <alex.popov@...ux.com> To: kernel-hardening@...ts.openwall.com, Kees Cook <keescook@...omium.org>, PaX Team <pageexec@...email.hu>, Brad Spengler <spender@...ecurity.net>, Ingo Molnar <mingo@...nel.org>, Andy Lutomirski <luto@...nel.org>, Tycho Andersen <tycho@...ho.ws>, Laura Abbott <labbott@...hat.com>, Mark Rutland <mark.rutland@....com>, Ard Biesheuvel <ard.biesheuvel@...aro.org>, Borislav Petkov <bp@...en8.de>, Thomas Gleixner <tglx@...utronix.de>, "H . Peter Anvin" <hpa@...or.com>, Peter Zijlstra <a.p.zijlstra@...llo.nl>, "Dmitry V . Levin" <ldv@...linux.org>, x86@...nel.org, Mohamed Ghannam <simo.ghannam@...il.com> Subject: Re: [PATCH RFC v8 0/6] Introduce the STACKLEAK feature and a test for it On 16.02.2018 21:10, Alexander Popov wrote: > This is the 8th version of the patch series introducing STACKLEAK to the > mainline kernel. I've made some minor improvements while waiting for the > next review by x86 maintainers. > > STACKLEAK is a security feature developed by Grsecurity/PaX (kudos to them), > which: > - reduces the information that can be revealed through kernel stack leak bugs; > - blocks some uninitialized stack variable attacks (e.g. CVE-2010-2963); > - introduces some runtime checks for kernel stack overflow detection. Hello! I've just tested STACKLEAK against the recent CVE-2017-17712 exploit: http://openwall.com/lists/oss-security/2018/02/20/1 This vulnerability is a race condition in raw_sendmsg() in net/ipv4/raw.c. It leads to uninitialized stack pointer usage which can be used for a local privilege escalation. CVE-2017-17712 was discovered and fixed by Mohamed Ghannam (kudos to him!). He also provided a stable PoC exploit for it. With STACKLEAK, the uninitialized stack pointer is set to STACKLEAK_POISON (-0xBEEF) and points to the unused hole in the virtual memory map. That blocks the stack spraying needed for CVE-2017-17712 exploit (similar to CVE-2010-2963). Best regards, Alexander
Powered by blists - more mailing lists
Confused about mailing lists and their use? Read about mailing lists on Wikipedia and check out these guidelines on proper formatting of your messages.