Re: [PATCH] af_unix: Add sockaddr length checks before accessing sa_family in bind and connect handlers

From: Mateusz Jurczyk <redacted>
Date: Thu,  8 Jun 2017 11:13:36 +0200

Verify that the caller-provided sockaddr structure is large enough to
contain the sa_family field, before accessing it in bind() and connect()
handlers of the AF_UNIX socket. Since neither syscall enforces a minimum
size of the corresponding memory region, very short sockaddrs (zero or
one byte long) result in operating on uninitialized memory while
referencing .sa_family.

Signed-off-by: Mateusz Jurczyk <redacted>

The sockaddr comes from a structure on the caller's kernel stack, even
if the user gives a smaller length, it is legal to access that memory.