overlay: remove stack allocations

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

diff --git a/src/lxc/storage/overlay.c b/src/lxc/storage/overlay.c
index 1a593b340dd2ab7f0b003cb2ceba63c3056749b1..4a43ec45ec948ffba679c80f0162e631e88707bf 100644 (file)
--- a/src/lxc/storage/overlay.c
+++ b/src/lxc/storage/overlay.c
@@ -35,6 +35,7 @@
 #include "log.h"
 #include "lxccontainer.h"
 #include "macro.h"
+#include "memory_utils.h"
 #include "overlay.h"
 #include "rsync.h"
 #include "storage.h"
@@ -491,8 +492,10 @@ bool ovl_detect(const char *path)
 
 int ovl_mount(struct lxc_storage *bdev)
 {
-       char *tmp, *options, *dup, *lower, *upper;
-       char *options_work, *work, *lastslash;
+       __do_free char *options = NULL,
+                                                        *options_work = NULL;
+       char *tmp, *dup, *lower, *upper;
+       char *work, *lastslash;
        int lastslashidx;
        size_t len, len2;
        unsigned long mntflags;
@@ -602,27 +605,27 @@ int ovl_mount(struct lxc_storage *bdev)
        if (mntdata) {
                len = strlen(lower) + strlen(upper) +
                      strlen("upperdir=,lowerdir=,") + strlen(mntdata) + 1;
-               options = alloca(len);
+               options = must_realloc(NULL, len);
                ret = snprintf(options, len, "upperdir=%s,lowerdir=%s,%s",
                               upper, lower, mntdata);
 
                len2 = strlen(lower) + strlen(upper) + strlen(work) +
                       strlen("upperdir=,lowerdir=,workdir=") +
                       strlen(mntdata) + 1;
-               options_work = alloca(len2);
+               options_work = must_realloc(NULL, len2);
                ret2 = snprintf(options, len2,
                                "upperdir=%s,lowerdir=%s,workdir=%s,%s", upper,
                                lower, work, mntdata);
        } else {
                len = strlen(lower) + strlen(upper) +
                      strlen("upperdir=,lowerdir=") + 1;
-               options = alloca(len);
+               options = must_realloc(NULL, len);
                ret = snprintf(options, len, "upperdir=%s,lowerdir=%s", upper,
                               lower);
 
                len2 = strlen(lower) + strlen(upper) + strlen(work) +
                       strlen("upperdir=,lowerdir=,workdir=") + 1;
-               options_work = alloca(len2);
+               options_work = must_realloc(NULL, len2);
                ret2 = snprintf(options_work, len2,
                                "upperdir=%s,lowerdir=%s,workdir=%s", upper,
                                lower, work);