netlabel: handle sparse category maps in netlbl_catmap_getlong()

In cases where the category bitmap is sparse enough that gaps exist
between netlbl_lsm_catmap structs, callers to netlbl_catmap_getlong()
could find themselves prematurely ending their search through the
category bitmap.  Further, the methods used to calculate the 'idx'
and 'off' values were incorrect for bitmaps this large.  This patch
changes the netlbl_catmap_getlong() behavior so that it always skips
over gaps and calculates the index and offset values correctly.

Signed-off-by: Paul Moore <paul@paul-moore.com>

diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
index bd007a9fd921471283ec5716a83a49b36197f337..3c070f2ba0f1ed2731cf982e08c46a07ff352815 100644 (file)
--- a/net/netlabel/netlabel_kapi.c
+++ b/net/netlabel/netlabel_kapi.c
@@ -609,20 +609,19 @@ int netlbl_catmap_getlong(struct netlbl_lsm_catmap *catmap,
                off = catmap->startbit;
                *offset = off;
        }
-       iter = _netlbl_catmap_getnode(&catmap, off, _CM_F_NONE, 0);
+       iter = _netlbl_catmap_getnode(&catmap, off, _CM_F_WALK, 0);
        if (iter == NULL) {
                *offset = (u32)-1;
                return 0;
        }
 
        if (off < iter->startbit) {
-               off = iter->startbit;
-               *offset = off;
+               *offset = iter->startbit;
+               off = 0;
        } else
                off -= iter->startbit;
-
        idx = off / NETLBL_CATMAP_MAPSIZE;
-       *bitmap = iter->bitmap[idx] >> (off % NETLBL_CATMAP_SIZE);
+       *bitmap = iter->bitmap[idx] >> (off % NETLBL_CATMAP_MAPSIZE);
 
        return 0;
 }