From Chrome renderer code exec to kernel with MSG_OOB
Posted by Jann Horn, Google Project Zero Introduction In early June, I was reviewing a new Linux kernel feature when I learned about the MSG_OOB feature supported by stream-oriented UNIX domain sockets. I reviewed the implementation of MSG_OOB, and discovered a security bug (CVE-2025-38236) affecting Linux >=6.9. I reported the bug to Linux, and it got fixed. Interestingly, while the MSG_OOB feature is not used by Chrome, it was exposed in the Chrome renderer sandbox. (Since then, sending MSG_OOB messages has been blocked in Chrome renderers in response to this issue.) The bug is pretty easy to trigger; the following [...]