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 5a49da2c550f3cb60f5ab619545ed571479f20d0..602458693ea32320e231a8ae3fa612866f2501c6 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++) {