unix: properly account for FDs passed over unix sockets

It is possible for a process to allocate and accumulate far more FDs than
the process' limit by sending them over a unix socket then closing them
to keep the process' fd count low.

This change addresses this problem by keeping track of the number of FDs
in flight per user and preventing non-privileged processes from having
more FDs in flight than their configured FD limit.

Reported-by: [email protected]
Reported-by: Tetsuo Handa <[email protected]>
Mitigates: CVE-2013-4312 (Linux 2.0+)
Suggested-by: Linus Torvalds <[email protected]>
Acked-by: Hannes Frederic Sowa <[email protected]>
Signed-off-by: Willy Tarreau <[email protected]>
Signed-off-by: David S. Miller <[email protected]>

0 files changed, 0 insertions, 0 deletions