Messages in this thread | | | From | Giuseppe Scrivano <> | Subject | Re: [PATCH v2 2/3] seccomp: Introduce addfd ioctl to seccomp user notifier | Date | Fri, 29 May 2020 11:24:33 +0200 |
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Sargun Dhillon <sargun@sargun.me> writes:
> This adds a seccomp notifier ioctl which allows for the listener to "add" > file descriptors to a process which originated a seccomp user > notification. This allows calls like mount, and mknod to be "implemented", > as the return value, and the arguments are data in memory. On the other > hand, calls like connect can be "implemented" using pidfd_getfd. > > Unfortunately, there are calls which return file descriptors, like > open, which are vulnerable to TOC-TOU attacks, and require that the > more privileged supervisor can inspect the argument, and perform the > syscall on behalf of the process generating the notifiation. This > allows the file descriptor generated from that open call to be > returned to the calling process. > > In addition, there is funcitonality to allow for replacement of > specific file descriptors, following dup2-like semantics. > > Signed-off-by: Sargun Dhillon <sargun@sargun.me> > Suggested-by: Matt Denton <mpdenton@google.com> > Cc: Kees Cook <keescook@google.com>, > Cc: Jann Horn <jannh@google.com>, > Cc: Robert Sesek <rsesek@google.com>, > Cc: Chris Palmer <palmer@google.com> > Cc: Christian Brauner <christian.brauner@ubuntu.com> > Cc: Tycho Andersen <tycho@tycho.ws> > ---
Thanks, this is a really useful feature.
Tested-by: Giuseppe Scrivano <gscrivan@redhat.com>
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