tree d26e642414ee3be9dbeb4d963b77a557eb62238b
parent 2a040f9f39d3b020c79e08dec26d12a7ce131c10
author Tycho Andersen <tycho@tycho.ws> 1519181266 -0700
committer Kees Cook <keescook@chromium.org> 1519260963 -0800

ptrace, seccomp: tweak get_metadata behavior slightly

Previously if users passed a small size for the input structure size, they
would get get odd behavior. It doesn't make sense to pass a structure
smaller than at least filter_off size, so let's just give -EINVAL in this
case.

This changes userspace visible behavior, but was only introduced in commit
26500475ac1b ("ptrace, seccomp: add support for retrieving seccomp
metadata") in 4.16-rc2, so should be safe to change if merged before then.

Reported-by: Eugene Syromiatnikov <esyr@redhat.com>
Signed-off-by: Tycho Andersen <tycho@tycho.ws>
CC: Kees Cook <keescook@chromium.org>
CC: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Kees Cook <keescook@chromium.org>