On Friday, September 18, 2015 03:27:03 PM Paul Osmialowski wrote:
> The goal of this patch is to reproduce on kdbus the same behavior
> that is expressed by Unix Domain Sockets when it comes to restricting
> ability to pass opened file descriptors.
>
> Signed-off-by: Paul Osmialowski <p.osmialo...@samsung.com>
> ---
> ipc/kdbus/message.c | 22 ++++++++++++++++++----
> 1 file changed, 18 insertions(+), 4 deletions(-)
Hi Paul,
I've been reworking my original kdbus LSM/SELinux hooks in order to simplify
things and make them a bit more consistent with the binder and other IPC-esque
hooks, I'm hoping to post a RFC for them soon.
A few comments below ...
> diff --git a/ipc/kdbus/message.c b/ipc/kdbus/message.c
> index ae565cd..b083431 100644
> --- a/ipc/kdbus/message.c
> +++ b/ipc/kdbus/message.c
> @@ -24,6 +24,7 @@
> #include <linux/sizes.h>
> #include <linux/slab.h>
> #include <linux/uaccess.h>
> +#include <linux/security.h>
> #include <net/sock.h>
>
> #include "bus.h"
> @@ -150,13 +151,19 @@ int kdbus_gaps_install(struct kdbus_gaps *gaps, struct
> kdbus_pool_slice *slice, for (i = 0; i < gaps->n_fds; ++i) {
> int fd;
>
> - fd = get_unused_fd_flags(O_CLOEXEC);
> - if (fd < 0)
> + if (gaps->fd_files[i] &&
> + security_file_receive(gaps->fd_files[i])) {
> incomplete_fds = true;
> + fds[n_fds++] = -1;
> + } else {
> + fd = get_unused_fd_flags(O_CLOEXEC);
> + if (fd < 0)
> + incomplete_fds = true;
My patch is a little different (no fd_files[i] validity check, diff if
structure, etc.) but the basic idea is the same.
> - WARN_ON(!gaps->fd_files[i]);
> + WARN_ON(!gaps->fd_files[i]);
You probably want to move this before the LSM hook.
> - fds[n_fds++] = fd < 0 ? -1 : fd;
> + fds[n_fds++] = fd < 0 ? -1 : fd;
> + }
> }
>
> /*
> @@ -178,6 +185,13 @@ int kdbus_gaps_install(struct kdbus_gaps *gaps, struct
> kdbus_pool_slice *slice, for (i = 0; i < gaps->n_memfds; ++i) {
> int memfd;
>
> + if (gaps->memfd_files[i] &&
> + security_file_receive(gaps->memfd_files[i])) {
> + incomplete_fds = true;
> + fds[n_fds++] = -1;
> + continue;
> + }
Similar to above, including the WARN_ON() movement.
> memfd = get_unused_fd_flags(O_CLOEXEC);
> if (memfd < 0) {
> incomplete_fds = true;
--
paul moore
security @ redhat
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