netlabel: fix out-of-bounds memory accesses

pcmoore · davem330 · commit 5578de4834fe · 2019-02-27T21:45:24.000-08:00
There are two array out-of-bounds memory accesses, one in cipso_v4_map_lvl_valid(), the other in netlbl_bitmap_walk(). Both errors are embarassingly simple, and the fixes are straightforward. As a FYI for anyone backporting this patch to kernels prior to v4.8, you'll want to apply the netlbl_bitmap_walk() patch to cipso_v4_bitmap_walk() as netlbl_bitmap_walk() doesn't exist before Linux v4.8. Reported-by: Jann Horn <jannh@google.com> Fixes: 446fda4 ("[NetLabel]: CIPSOv4 engine") Fixes: 3faa8f9 ("netlabel: Move bitmap manipulation functions to the NetLabel core.") Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
@@ -667,7 +667,8 @@ static int cipso_v4_map_lvl_valid(const struct cipso_v4_doi *doi_def, u8 level)
 	case CIPSO_V4_MAP_PASS:
 		return 0;
 	case CIPSO_V4_MAP_TRANS:
-		if (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL)
+		if ((level < doi_def->map.std->lvl.cipso_size) &&
+		    (doi_def->map.std->lvl.cipso[level] < CIPSO_V4_INV_LVL))
 			return 0;
 		break;
 	}
diff --git a/net/netlabel/netlabel_kapi.c b/net/netlabel/netlabel_kapi.c
@@ -903,7 +903,8 @@ int netlbl_bitmap_walk(const unsigned char *bitmap, u32 bitmap_len,
 		    (state == 0 && (byte & bitmask) == 0))
 			return bit_spot;
 
-		bit_spot++;
+		if (++bit_spot >= bitmap_len)
+			return -1;
 		bitmask >>= 1;
 		if (bitmask == 0) {
 			byte = bitmap[++byte_offset];
