Fwd: [oss-security] "I miss LSD", slides, paper and tools relating to finding UNIX system level vulnerabilities (as given at 44CON)

[Mouse]

> My understanding is that the new code, by passing shared memory
> through fd is a lot better since [...]

In those respects, yes.  But it's worse in that it requires write
access to a filesystem - a filesystem which supports mmap - with space
enough to hold the shared memory segments, which MIT-SHM doesn't.

Tradeoffs, tradeoffs....

> it doesn't rely on file system permissions to control access,

Neither does MIT-SHM, I thought.  I thought it relied on shared memory
segment permissions (which in some respects look and work like
filesystem permissions, but actually have nothing to do with any
filesystem).

What I think this _really_ needs is either a way to pass access to a
chunk of memory through sockets a la SCM_RIGHTS, or a way to create a
file descriptor which is mmappable but doesn't depend on anything in
any filesystem.  (I'd prefer the former; after all, "access rights"
covers a lot more than file descriptors - and I've wished for it often
enough before; it would hardly be specific to this application.)

/~\ The ASCII				  Mouse
\ / Ribbon Campaign
 X  Against HTML		mouse at rodents-montreal.org
/ \ Email!	     7D C8 61 52 5D E7 2D 39  4E F1 31 3E E8 B3 27 4B