Fix: runas worker attempts to send invalid fd to master

[lttng-tools.git] / src / common / runas.c

diff --git a/src/common/runas.c b/src/common/runas.c
index 4bd356a0499f2119a227a69b324ab5248d7ba8a0..c4bb298bfab938735aba850bb163cefa1e0424cd 100644 (file)
--- a/src/common/runas.c
+++ b/src/common/runas.c
@@ -329,7 +329,8 @@ int do_send_fd(int sock, int fd)
        ssize_t len;
 
        if (fd < 0) {
        ssize_t len;
 
        if (fd < 0) {

-               ERR("Invalid file description");
+               ERR("Attempt to send invalid file descriptor to master (fd = %i)", fd);
+               /* Return 0 as this is not a fatal error. */

                return 0;
        }
 
                return 0;
        }
 


@@ -346,11 +347,6 @@ int do_recv_fd(int sock, int *fd)
 {
        ssize_t len;
 
 {
        ssize_t len;
 

-       if (*fd < 0) {
-               ERR("Invalid file description");
-               return 0;
-       }
-

        len = lttcomm_recv_fds_unix_sock(sock, fd, 1);
 
        if (!len) {
        len = lttcomm_recv_fds_unix_sock(sock, fd, 1);
 
        if (!len) {


@@ -359,6 +355,12 @@ int do_recv_fd(int sock, int *fd)
                PERROR("lttcomm_recv_fds_unix_sock");
                return -1;
        }
                PERROR("lttcomm_recv_fds_unix_sock");
                return -1;
        }

+       if (*fd < 0) {
+               ERR("Invalid file descriptor received from worker (fd = %i)", *fd);
+               /* Return 0 as this is not a fatal error. */
+               return 0;
+       }
+

        return 0;
 }
 
        return 0;
 }
 


@@ -375,6 +377,11 @@ int send_fd_to_worker(struct run_as_worker *worker, enum run_as_cmd cmd, int fd)
                return 0;
        }
 
                return 0;
        }
 

+       if (fd < 0) {
+               ERR("Refusing to send invalid fd to worker (fd = %i)", fd);
+               return -1;
+       }
+

        ret = do_send_fd(worker->sockpair[0], fd);
        if (ret < 0) {
                PERROR("do_send_fd");
        ret = do_send_fd(worker->sockpair[0], fd);
        if (ret < 0) {
                PERROR("do_send_fd");


@@ -396,20 +403,21 @@ int send_fd_to_master(struct run_as_worker *worker, enum run_as_cmd cmd, int fd)
                return 0;
        }
 
                return 0;
        }
 

+       if (fd < 0) {
+               DBG("Not sending file descriptor to master as it is invalid (fd = %i)", fd);
+               return 0;
+       }

        ret = do_send_fd(worker->sockpair[1], fd);
        if (ret < 0) {
                PERROR("do_send_fd error");
                ret = -1;
        }
 
        ret = do_send_fd(worker->sockpair[1], fd);
        if (ret < 0) {
                PERROR("do_send_fd error");
                ret = -1;
        }
 

-       if (fd < 0) {
-               goto end;
-       }

        ret_close = close(fd);
        if (ret_close < 0) {
                PERROR("close");
        }
        ret_close = close(fd);
        if (ret_close < 0) {
                PERROR("close");
        }

-end:
+

        return ret;
 }
 
        return ret;
 }
 


@@ -726,6 +734,11 @@ int run_as_cmd(struct run_as_worker *worker,
                goto end;
        }
 
                goto end;
        }
 

+       if (ret_value->_error) {
+               /* Skip stage 5 on error as there will be no fd to receive. */
+               goto end;
+       }
+

        /*
         * Stage 5: Receive file descriptor if needed
         */
        /*
         * Stage 5: Receive file descriptor if needed
         */