www.secnews.physaphae.fr This is the RSS 2.0 feed from www.secnews.physaphae.fr. IT's a simple agragated flow of multiple articles soruces. Liste of sources, can be found on www.secnews.physaphae.fr. 2024-06-26T09:33:21+00:00 www.secnews.physaphae.fr ProjectZero - Blog de recherche Google Racing against the clock -- hitting a tiny kernel race window https://crbug.com/project-zero/2247) in the Linux kernel. (While trying to explain to someone how the fix for CVE-2021-0920 worked - I was explaining why the Unix GC is now safe, and then got confused because I couldn't actually figure out why it's safe after that fix, eventually realizing that it actually isn't safe.) It's a fairly narrow race window, so I was wondering whether it could be hit with a small number of attempts - especially on kernels that aren't built with CONFIG_PREEMPT, which would make it possible to preempt a thread with another thread, as I described at LSSEU2019. This is a writeup of how I managed to hit the race on a normal Linux desktop kernel, with a hit rate somewhere around 30% if the proof of concept has been tuned for the specific machine. I didn't do a full exploit though, I stopped at getting evidence of use-after-free (UAF) accesses (with the help of a very large file descriptor table and userfaultfd, which might not be available to normal users depending on system configuration) because that's the part I was curious about. This also demonstrates that even very small race conditions can still be exploitable if someone sinks enough time into writing an exploit, so be careful if you dismiss very small race windows as unexploitable or don't treat such issues as security bugs. The UAF reproducer is in our bugtracker.The bug In the UNIX domain socket garbage collection code (which is needed to deal with reference loops formed by UNIX domain sockets that use SCM_RIGHTS ]]> 2022-08-24T12:08:43+00:00 https://googleprojectzero.blogspot.com/2022/03/racing-against-clock-hitting-tiny.html www.secnews.physaphae.fr/article.php?IdArticle=8221935 False Tool,Guideline APT 25 2.0000000000000000