Path and name length should not be placed in constant
size buffer but in allocated memory.

Use also PATH_MAX macro from limits.h instead of internal
library macro. Handle overflows of snprintf in related funcitons.

Signed-off-by: Krzysztof Opasiak <k.opas...@samsung.com>
---
 src/usbg.c |  177 ++++++++++++++++++++++++++++++++++++++++--------------------
 1 file changed, 118 insertions(+), 59 deletions(-)

diff --git a/src/usbg.c b/src/usbg.c
index 171f8f4..2da4a63 100644
--- a/src/usbg.c
+++ b/src/usbg.c
@@ -82,8 +82,8 @@ struct usbg_binding
        usbg_config *parent;
        usbg_function *target;
 
-       char name[USBG_MAX_NAME_LENGTH];
-       char path[USBG_MAX_PATH_LENGTH];
+       char *name;
+       char *path;
 };
 
 /**
@@ -410,6 +410,8 @@ static inline int usbg_write_string(char *path, char *name, 
char *file,
 
 static inline void usbg_free_binding(usbg_binding *b)
 {
+       free(b->path);
+       free(b->name);
        free(b);
 }
 
@@ -534,6 +536,28 @@ static usbg_function *usbg_allocate_function(char *path, 
char *name,
        return f;
 }
 
+static usbg_binding *usbg_allocate_binding(char *path, char *name,
+               usbg_config *parent)
+{
+       usbg_binding *b;
+
+       b = malloc(sizeof(usbg_config));
+       if (b) {
+               b->name = strdup(name);
+               b->path = strdup(path);
+               b->parent = parent;
+
+               if (!(b->name) || !(b->path)) {
+                       free(b->name);
+                       free(b->path);
+                       free(b);
+                       b = NULL;
+               }
+       }
+
+       return b;
+}
+
 static int usbg_parse_function_net_attrs(usbg_function *f,
                usbg_function_attrs *f_attrs)
 {
@@ -689,52 +713,64 @@ static int usbg_parse_config_bindings(usbg_config *c)
        int i, n, nmb;
        int ret = USBG_SUCCESS;
        struct dirent **dent;
-       char bpath[USBG_MAX_PATH_LENGTH];
-       char file_name[USBG_MAX_PATH_LENGTH];
-       char target[USBG_MAX_STR_LENGTH];
+       char bpath[PATH_MAX];
+       char target[PATH_MAX];
        char *target_name;
+       int end;
        usbg_gadget *g = c->parent;
        usbg_binding *b;
        usbg_function *f;
 
-       sprintf(bpath, "%s/%s", c->path, c->name);
+       end = snprintf(bpath, PATH_MAX, "%s/%s", c->path, c->name);
+       if (end >= PATH_MAX) {
+               ret = USBG_ERROR_PATH_TOO_LONG;
+               goto out;
+       }
 
        n = scandir(bpath, &dent, bindings_select, alphasort);
-       if (n >= 0) {
-               for (i = 0; i < n; i++) {
-                       sprintf(file_name, "%s/%s", bpath, dent[i]->d_name);
-                       nmb = readlink(file_name, target, USBG_MAX_PATH_LENGTH);
-                       if (nmb >= 0) {
-                               /* readlink() don't add this,
-                                * so we have to do it manually */
-                               target[nmb] = '\0';
-                               /* Target contains a full path
-                                * but we need only function dir name */
-                               target_name = strrchr(target, '/') + 1;
-
-                               f = usbg_get_function(g, target_name);
-
-                               b = malloc(sizeof(usbg_binding));
-                               if (b) {
-                                       strcpy(b->name, dent[i]->d_name);
-                                       strcpy(b->path, bpath);
-                                       b->target = f;
-                               b->parent = c;
-                                       TAILQ_INSERT_TAIL(&c->bindings, b, 
bnode);
+       if (n < 0) {
+               ret = usbg_translate_error(errno);
+               goto out;
+       }
+
+       for (i = 0; i < n; i++) {
+               if (ret == USBG_SUCCESS) {
+                       nmb = snprintf(&(bpath[end]), PATH_MAX - end, "/%s",
+                                       dent[i]->d_name);
+
+                       if (nmb < PATH_MAX) {
+                               nmb = readlink(bpath, target, PATH_MAX);
+                               if (nmb >= 0) {
+                                       /* readlink() don't add this,
+                                        * so we have to do it manually */
+                                       target[nmb] = '\0';
+                                       /* Target contains a full path
+                                        * but we need only function dir name */
+                                       target_name = strrchr(target, '/') + 1;
+
+                                       f = usbg_get_function(g, target_name);
+
+                                       /* We have to cut last part of path */
+                                       bpath[end] = '\0';
+                                       b = usbg_allocate_binding(bpath, 
dent[i]->d_name, c);
+                                       if (b) {
+                                               b->target = f;
+                                               TAILQ_INSERT_TAIL(&c->bindings, 
b, bnode);
+                                       } else {
+                                               ret = USBG_ERROR_NO_MEM;
+                                       }
                                } else {
-                                       ret = USBG_ERROR_NO_MEM;
+                                       ret = usbg_translate_error(errno);
                                }
                        } else {
-                               ret = usbg_translate_error(errno);
+                               ret = USBG_ERROR_PATH_TOO_LONG;
                        }
-
-                       free(dent[i]);
-               }
-               free(dent);
-       } else {
-               ret = usbg_translate_error(errno);
+               } /* ret == USBG_SUCCESS */
+               free(dent[i]);
        }
+       free(dent);
 
+out:
        return ret;
 }
 
@@ -1603,50 +1639,73 @@ int usbg_set_config_string(usbg_config *c, int lang, 
char *str)
 
 int usbg_add_config_function(usbg_config *c, char *name, usbg_function *f)
 {
-       char bpath[USBG_MAX_PATH_LENGTH];
-       char fpath[USBG_MAX_PATH_LENGTH];
+       char bpath[PATH_MAX];
+       char fpath[PATH_MAX];
        usbg_binding *b;
        int ret = USBG_SUCCESS;
+       int nmb;
 
-       if (!c || !f)
-               return USBG_ERROR_INVALID_PARAM;
+       if (!c || !f) {
+               ret = USBG_ERROR_INVALID_PARAM;
+               goto out;
+       }
 
        b = usbg_get_binding(c, name);
        if (b) {
                ERROR("duplicate binding name\n");
-               return USBG_ERROR_EXIST;
+               ret = USBG_ERROR_EXIST;
+               goto out;
        }
 
        b = usbg_get_link_binding(c, f);
        if (b) {
                ERROR("duplicate binding link\n");
-               return USBG_ERROR_EXIST;
+               ret = USBG_ERROR_EXIST;
+               goto out;
        }
 
-       sprintf(bpath, "%s/%s/%s", c->path, c->name, name);
-       sprintf(fpath, "%s/%s", f->path, f->name);
-
-       b = malloc(sizeof(usbg_binding));
-       if (!b) {
-               ERRORNO("allocating binding\n");
-               return USBG_ERROR_NO_MEM;
+       nmb = snprintf(fpath, PATH_MAX, "%s/%s", f->path, f->name);
+       if (nmb >= PATH_MAX) {
+               ret = USBG_ERROR_PATH_TOO_LONG;
+               goto out;
        }
 
-       ret = symlink(fpath, bpath);
-       if (ret < 0) {
-               ERRORNO("%s -> %s\n", bpath, fpath);
-               return ret;
-       } else {
-               ret = USBG_SUCCESS;
+       nmb = snprintf(bpath, PATH_MAX, "%s/%s", c->path, c->name);
+       if (nmb >= PATH_MAX) {
+               ret = USBG_ERROR_PATH_TOO_LONG;
+               goto out;
        }
 
-       strcpy(b->name, name);
-       strcpy(b->path, bpath);
-       b->target = f;
-       b->parent = c;
+       b = usbg_allocate_binding(bpath, name, c);
+       if (b) {
+               int free_space = PATH_MAX - nmb;
+
+               b->target = f;
+               nmb = snprintf(&(bpath[nmb]), free_space, "/%s", name);
+               if (nmb < free_space) {
+
+                       ret = symlink(fpath, bpath);
+                       if (ret == 0) {
+                               b->target = f;
+                               INSERT_TAILQ_STRING_ORDER(&c->bindings, bhead,
+                                               name, b, bnode);
+                       } else {
+                               ERRORNO("%s -> %s\n", bpath, fpath);
+                               ret = usbg_translate_error(errno);
+                       }
+               } else {
+                       ret = USBG_ERROR_PATH_TOO_LONG;
+               }
 
-       INSERT_TAILQ_STRING_ORDER(&c->bindings, bhead, name, b, bnode);
+               if (ret != USBG_SUCCESS) {
+                       usbg_free_binding(b);
+                       b = NULL;
+               }
+       } else {
+               ret = USBG_ERROR_NO_MEM;
+       }
 
+out:
        return ret;
 }
 
-- 
1.7.9.5

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