Jann Horn <jannh@xxxxxxxxxx> writes: > > In my opinion, CVE-2019-5736 points out two different problems: > > The big problem: The __ptrace_may_access() logic has a special-case > short-circuit for "introspection" that you can't opt out of; Once upon a time in a galaxy far far away I fixed a bug where we missing ptrace_may_access checks on various proc files and systems using selinux stopped working. At the time selinux did not allow ptrace like access to yourself. The "introspection" special case was the quick and simple work-around. There is nothing fundamental in having the "introspection" special case except that various lsms have probably grown to depend upon it being there. I expect without difficulty we could move the check down into the various lsms. Which would get that check out of the core kernel code. Then the special case would the lsms challenge to keep or remove. Eric
