PaX Team retweeted
Lol, nice silent fix in 6.6 on arch/x86/kernel/cpu/amd.c, smuggled in a reused "No functional changes" commit. It was no functional changes when the code was moved from the common Zen handler, not when it got moved out of the Zen1-specific handler. #grsecurity not affected
planning your next monitor setup for coding? this table might come handy. the UHD/100%/125% data was actually measured with Source Code Pro (Regular weight), the rest is extrapolated and YMMV of course.
PaX Team retweeted
About time someone said what needed to be said: seclists.org/oss-sec/2025/q2…
While we did this for security purposes, you don't have to be security-oriented, this is generic OS research.
PaX Team retweeted
Slides for @wipawel's H2HC presentation this month on the TLB are now available on grsecurity.net/papers
If you've never heard of "paging-structure caches" before, check it out!
PaX Team retweeted
Our analysis of Intel CAT feature as a cache side-channel mitigation. Tl;dr don’t. @bsdaemon langsechq.gitlab.io/spw24/pa…
PaX Team retweeted
We need to post a correction to yesterday's eBPF performance numbers:
@_minipli wasn't happy with just a 30x speedup and took a look at one final bottleneck that was bothering him.
The speedup over vanilla is now 747x 🤯 (5.27s vs 1h5m40s)
Performance isn't the enemy of security: we care about both. Today's patches finish off a set of security/performance improvements to eBPF. Below we show a ~30x speedup vs vanilla in running the eBPF selftests with every single #grsecurity option enabled!
PaX Team retweeted
Performance isn't the enemy of security: we care about both. Today's patches finish off a set of security/performance improvements to eBPF. Below we show a ~30x speedup vs vanilla in running the eBPF selftests with every single #grsecurity option enabled!
PaX Team retweeted
The first ever end-to-end cross-process Spectre exploit? I worked on this during an internship with @grsecurity! An in-depth write-up here:
grsecurity.net/cross_process…
not to mention that it's all nicely documented at gcc.gnu.org/onlinedocs/gcc/C… and gcc.gnu.org/onlinedocs/gcc/I… :)
Actually, don't even need that, as found by @paxteam, just need to use the proper no_sanitize() attribute. Replace the first line in the test at: lore.kernel.org/all/ZvFGwKfo… with: #define __nsa __attribute__((no_sanitize("hwaddress", "kernel-hwaddress")))
PaX Team retweeted
No takers, so here's a full timeline of CVE-2024-26972 and how the Linux CNA's automation produces garbage that people act on (posting in 20 Xcretes would be a pain): grsecurity.net/~spender/cve_…
@wipawel's CVE system today produced a dump of ~50 "interesting" Linux kernel CVEs.
Walk through CVE-2024-26972 (current link: nvd.nist.gov/vuln/detail/CVE…, previous link: lore.kernel.org/linux-cve-an…) and its automated updates and see if you as an end-user can make heads or tails of it.
PaX Team retweeted
In today's blog post, @_minipli shows how we were able to use a newer C feature and a GCC plugin addition to ease our maintenance burden, reducing grsecurity's patch size by over a megabyte with no change in functionality. Enjoy! grsecurity.net/reducing_main…
PaX Team retweeted
In this blog, we dive deep into how the automation employed by the recently-formed Linux CNA managed to take a detailed, unrestricted vulnerability report for their 5.10 LTS kernel, and produce an error-filled CVE unhelpful for downstream consumers: grsecurity.net/cve-2021-4440…
PaX Team retweeted
Thank you, Peter, for this concise description of the PAX_SIZE_OVERFLOW GCC plugin! Created in 2012, it was one of the first GCC plugins added to grsecurity. It was very advanced for its time, and in 2024, still is: lists.openwall.net/linux-har…
PaX Team retweeted
The purpose of the CVE system isn't a "first scrub" of potential issues based on automated commit message greps. You can't say the problem is a handful of bogus CVEs and also say the solution is to flood the system with 100x more of them and expect people to fix the created mess.
PaX Team retweeted
A weakness 23 years in the making: binaries and libraries built with an older toolchain act as timebombs against ASLR under "recent" Linux kernel and glibc changes.
Users: Check your exposure!
Developers: Rebuild binaries to achieve full ASLR benefit!
grsecurity.net/toolchain_nec…
PaX Team retweeted
A short Friday afternoon blog announcing a new version of paxtest with some useful new tests to get you ready for Monday! grsecurity.net/paxtest_relea…
PaX Team retweeted
Ow, the talks for #H2HC2023 are really looking amazing! Thanks to all who submitted and to our outstanding technical commitee!
@spendergrsec @paxteam @pinkflawd @matrosov @h2hconference
Acabamos de publicar mais 4 palestrantes. A grade da #H2HC2023 esta epica. 20 anos de @h2hconference h2hc.com.br