commands: remove stack allocations

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>

diff --git a/src/lxc/commands.c b/src/lxc/commands.c
index 5f2e25b6dcb119ac35f34f3da2198be95e47d62b..5057d5512d097946bbf0d45f356692c53a33d328 100644 (file)
--- a/src/lxc/commands.c
+++ b/src/lxc/commands.c
@@ -48,6 +48,7 @@
 #include "lxc.h"
 #include "lxclock.h"
 #include "mainloop.h"
+#include "memory_utils.h"
 #include "monitor.h"
 #include "start.h"
 #include "terminal.h"
@@ -524,8 +525,8 @@ char *lxc_cmd_get_config_item(const char *name, const char *item,
 static int lxc_cmd_get_config_item_callback(int fd, struct lxc_cmd_req *req,
                                            struct lxc_handler *handler)
 {
+       __do_free char *cidata = NULL;
        int cilen;
-       char *cidata;
        struct lxc_config_t *item;
        struct lxc_cmd_rsp rsp;
 
@@ -538,7 +539,7 @@ static int lxc_cmd_get_config_item_callback(int fd, struct lxc_cmd_req *req,
        if (cilen <= 0)
                goto err1;
 
-       cidata = alloca(cilen + 1);
+       cidata = must_realloc(NULL, cilen + 1);
        if (item->get(req->data, cidata, cilen + 1, handler->conf, NULL) != cilen)
                goto err1;
 
@@ -1103,9 +1104,9 @@ static void lxc_cmd_fd_cleanup(int fd, struct lxc_handler *handler,
 static int lxc_cmd_handler(int fd, uint32_t events, void *data,
                           struct lxc_epoll_descr *descr)
 {
+       __do_free void *reqdata = NULL;
        int ret;
        struct lxc_cmd_req req;
-       void *reqdata = NULL;
        struct lxc_handler *handler = data;
 
        ret = lxc_abstract_unix_rcv_credential(fd, &req, sizeof(req));
@@ -1143,21 +1144,7 @@ static int lxc_cmd_handler(int fd, uint32_t events, void *data,
        }
 
        if (req.datalen > 0) {
-               /* LXC_CMD_CONSOLE_LOG needs to be able to allocate data
-                * that exceeds LXC_CMD_DATA_MAX: use malloc() for that.
-                */
-               if (req.cmd == LXC_CMD_CONSOLE_LOG)
-                       reqdata = malloc(req.datalen);
-               else
-                       reqdata = alloca(req.datalen);
-               if (!reqdata) {
-                       ERROR("Failed to allocate memory for \"%s\" command",
-                             lxc_cmd_str(req.cmd));
-                       errno = ENOMEM;
-                       ret = -ENOMEM;
-                       goto out_close;
-               }
-
+               reqdata = must_realloc(NULL, req.datalen);
                ret = lxc_recv_nointr(fd, reqdata, req.datalen, 0);
                if (ret != req.datalen) {
                        WARN("Failed to receive full command request. Ignoring "
@@ -1177,9 +1164,6 @@ static int lxc_cmd_handler(int fd, uint32_t events, void *data,
        }
 
 out:
-       if (req.cmd == LXC_CMD_CONSOLE_LOG && reqdata)
-               free(reqdata);
-
        return ret;
 
 out_close: