Applied.
On Fri, Jan 20, 2017 at 2:39 PM, Gris Ge <fge@xxxxxxxxxx> wrote:
Problem:
A non-root user could send and execute 'shutdown' IPC command to
multipathd.
Fix:
Use getsockopt() to find out socket client uid, only query (list or
show) command are allowed for non-root(uid != 0) socket connection.
An error message "permission deny: need to be root" will be sent
otherwise.
Signed-off-by: Gris Ge <fge@xxxxxxxxxx>
---
multipathd/main.c | 12 +++++++++++-
multipathd/uxlsnr.c | 19 +++++++++++++++++++
multipathd/uxlsnr.h | 4 +++-
3 files changed, 33 insertions(+), 2 deletions(-)
diff --git a/multipathd/main.c b/multipathd/main.c
index adc3258..1e64afc 100644
--- a/multipathd/main.c
+++ b/multipathd/main.c
@@ -23,6 +23,7 @@
#endif
#include <semaphore.h>
#include <time.h>
+#include <stdbool.h>
/*
* libmultipath
@@ -1048,7 +1049,8 @@ map_discovery (struct vectors * vecs)
}
int
-uxsock_trigger (char * str, char ** reply, int * len, void * trigger_data)
+uxsock_trigger (char * str, char ** reply, int * len, bool is_root,
+ void * trigger_data)
{
struct vectors * vecs;
int r;
@@ -1057,6 +1059,14 @@ uxsock_trigger (char * str, char ** reply, int * len, void * trigger_data)
*len = 0;
vecs = (struct vectors *)trigger_data;
+ if ((str != NULL) && (is_root == false) &&
+ (strncmp(str, "list", strlen("list")) != 0) &&
+ (strncmp(str, "show", strlen("show")) != 0)) {
+ *reply = STRDUP("permission deny: need to be root");
+ *len = strlen(*reply) + 1;
+ return 1;
+ }
+
r = parse_cmd(str, reply, len, vecs, uxsock_timeout / 1000);
if (r > 0) {
diff --git a/multipathd/uxlsnr.c b/multipathd/uxlsnr.c
index 6ca62af..98ac25a 100644
--- a/multipathd/uxlsnr.c
+++ b/multipathd/uxlsnr.c
@@ -22,6 +22,7 @@
#include <poll.h>
#include <sys/time.h>
#include <signal.h>
+#include <stdbool.h>
#include "checkers.h"
#include "memory.h"
#include "debug.h"
@@ -51,6 +52,23 @@ LIST_HEAD(clients);
pthread_mutex_t client_lock = PTHREAD_MUTEX_INITIALIZER;
struct pollfd *polls;
+static bool _socket_client_is_root(int fd);
+
+static bool _socket_client_is_root(int fd)
+{
+ socklen_t len = 0;
+ struct ucred uc;
+
+ len = sizeof(struct ucred);
+ if ((fd >= 0) &&
+ (getsockopt(fd, SOL_SOCKET, SO_PEERCRED, &uc, &len) == 0) &&
+ (uc.uid == 0))
+ return true;
+
+ /* Treat error as not root client */
+ return false;
+}
+
/*
* handle a new client joining
*/
@@ -255,6 +273,7 @@ void * uxsock_listen(uxsock_trigger_fn uxsock_trigger, void * trigger_data)
condlog(4, "cli[%d]: Got request [%s]",
i, inbuf);
uxsock_trigger(inbuf, &reply, &rlen,
+ _socket_client_is_root(c->fd),
trigger_data);
if (reply) {
if (send_packet(c->fd,
diff --git a/multipathd/uxlsnr.h b/multipathd/uxlsnr.h
index 4ef47d5..d51a8f9 100644
--- a/multipathd/uxlsnr.h
+++ b/multipathd/uxlsnr.h
@@ -1,7 +1,9 @@
#ifndef _UXLSNR_H
#define _UXLSNR_H
-typedef int (uxsock_trigger_fn)(char *, char **, int *, void *);
+#include <stdbool.h>
+
+typedef int (uxsock_trigger_fn)(char *, char **, int *, bool, void *);
void * uxsock_listen(uxsock_trigger_fn uxsock_trigger,
void * trigger_data);
--
1.8.3.1
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