Commit 389abe1d authored by Prasad J Pandit's avatar Prasad J Pandit Committed by Jason Wang
Browse files

net: tap: replace snprintf with g_strdup_printf calls 



When invoking qemu-bridge-helper in 'net_bridge_run_helper',
instead of using fixed sized buffers, use dynamically allocated
ones initialised and returned by g_strdup_printf().

Signed-off-by: default avatarPrasad J Pandit <pjp@fedoraproject.org>
Reviewed-by: default avatarLi Qiang <liq3ea@gmail.com>
Reviewed-by: default avatarDaniel P. Berrangé <berrange@redhat.com>
Signed-off-by: default avatarJason Wang <jasowang@redhat.com>
parent 3283dde4

net/tap.c

+11 −8
Original line number Diff line number Diff line
@@ -498,9 +498,9 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, 
    }

    if (pid == 0) {

        int open_max = sysconf(_SC_OPEN_MAX), i;

        char fd_buf[6+10];

        char br_buf[6+IFNAMSIZ] = {0};

        char helper_cmd[PATH_MAX + sizeof(fd_buf) + sizeof(br_buf) + 15];

        char *fd_buf = NULL;

        char *br_buf = NULL;

        char *helper_cmd = NULL;



        for (i = 3; i < open_max; i++) {

            if (i != sv[1]) {
@@ -508,17 +508,17 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, 
            }

        }



        snprintf(fd_buf, sizeof(fd_buf), "%s%d", "--fd=", sv[1]);

        fd_buf = g_strdup_printf("%s%d", "--fd=", sv[1]);



        if (strrchr(helper, ' ') || strrchr(helper, '\t')) {

            /* assume helper is a command */



            if (strstr(helper, "--br=") == NULL) {

                snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);

                br_buf = g_strdup_printf("%s%s", "--br=", bridge);

            }



            snprintf(helper_cmd, sizeof(helper_cmd), "%s %s %s %s",

                     helper, "--use-vnet", fd_buf, br_buf);

            helper_cmd = g_strdup_printf("%s %s %s %s", helper,

                            "--use-vnet", fd_buf, br_buf ? br_buf : "");



            parg = args;

            *parg++ = (char *)"sh";
@@ -527,10 +527,11 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, 
            *parg++ = NULL;



            execv("/bin/sh", args);

            g_free(helper_cmd);

        } else {

            /* assume helper is just the executable path name */



            snprintf(br_buf, sizeof(br_buf), "%s%s", "--br=", bridge);

            br_buf = g_strdup_printf("%s%s", "--br=", bridge);



            parg = args;

            *parg++ = (char *)helper;
@@ -541,6 +542,8 @@ static int net_bridge_run_helper(const char *helper, const char *bridge, 


            execv(helper, args);

        }

        g_free(fd_buf);

        g_free(br_buf);

        _exit(1);



    } else {