libfstools: support file paths longer than 255 chars

Alloc globdir buffer dynamically and simply use realloc when needed.
This fixes e.g. segmentation fault in jffs2reset due to an infinite
recurrency when dealing with longs paths.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

diff --git a/libfstools/overlay.c b/libfstools/overlay.c
index 8423a57c36df8fd67b445c3ff76ecc9b2afd8db6..e610b8d36e7342190352c463eac6cd87ec87abb3 100644 (file)
--- a/libfstools/overlay.c
+++ b/libfstools/overlay.c
@@ -67,15 +67,29 @@ handle_rmdir(const char *dir)
 void
 foreachdir(const char *dir, int (*cb)(const char*))
 {
+       static char *globdir = NULL;
+       static size_t globdirlen = 0;
        struct stat s = { 0 };
-       char globdir[256];
+       size_t dirlen = strlen(dir);
        glob_t gl;
        int j;
 
-       if (dir[strlen(dir) - 1] == '/')
-               snprintf(globdir, 256, "%s*", dir);
+       if (dirlen + sizeof("/*") > globdirlen) {
+               /* Alloc extra 256 B to avoid too many reallocs */
+               size_t len = dirlen + sizeof("/*") + 256;
+               char *tmp;
+
+               tmp = realloc(globdir, len);
+               if (!tmp)
+                       return;
+               globdir = tmp;
+               globdirlen = len;
+       }
+
+       if (dir[dirlen - 1] == '/')
+               sprintf(globdir, "%s*", dir);
        else
-               snprintf(globdir, 256, "%s/*", dir); /**/
+               sprintf(globdir, "%s/*", dir);
 
        if (!glob(globdir, GLOB_NOESCAPE | GLOB_MARK | GLOB_ONLYDIR, NULL, &gl))
                for (j = 0; j < gl.gl_pathc; j++) {