[RFC] kdbus: use LSM hooks to restrict ability to send file descriptors
From: Paul Osmialowski
Date: Fri Sep 18 2015 - 09:28:06 EST
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.osmialowsk@xxxxxxxxxxx>
---
ipc/kdbus/message.c | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
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;
- WARN_ON(!gaps->fd_files[i]);
+ WARN_ON(!gaps->fd_files[i]);
- 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;
+ }
+
memfd = get_unused_fd_flags(O_CLOEXEC);
if (memfd < 0) {
incomplete_fds = true;
--
1.9.1
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/