netfilter: xt_hashlimit: use _ALL macro to reject unknown flag bits

David Miller says: The canonical way to validate if the set bits are in a valid range is to have a "_ALL" macro, and test: if (val & ~XT_HASHLIMIT_ALL) goto err;" make it so. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nomis · May 16, 2012 · 1f27e25 · 1f27e25
1 parent 6d8823d
commit 1f27e25
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Showing 2 changed files with 5 additions and 3 deletions.
diff --git a/include/linux/netfilter/xt_hashlimit.h b/include/linux/netfilter/xt_hashlimit.h
@@ -22,10 +22,12 @@ enum {
 	XT_HASHLIMIT_HASH_SPT = 1 << 3,
 	XT_HASHLIMIT_INVERT   = 1 << 4,
 	XT_HASHLIMIT_BYTES    = 1 << 5,
+};
 #ifdef __KERNEL__
-	XT_HASHLIMIT_MAX      = 1 << 6,
+#define XT_HASHLIMIT_ALL (XT_HASHLIMIT_HASH_DIP | XT_HASHLIMIT_HASH_DPT | \
+			  XT_HASHLIMIT_HASH_SIP | XT_HASHLIMIT_HASH_SPT | \
+			  XT_HASHLIMIT_INVERT | XT_HASHLIMIT_BYTES)
 #endif
-};
 
 struct hashlimit_cfg {
 	__u32 mode;	  /* bitmask of XT_HASHLIMIT_HASH_* */

diff --git a/net/netfilter/xt_hashlimit.c b/net/netfilter/xt_hashlimit.c
@@ -647,7 +647,7 @@ static int hashlimit_mt_check(const struct xt_mtchk_param *par)
 			return -EINVAL;
 	}
 
-	if (info->cfg.mode >= XT_HASHLIMIT_MAX) {
+	if (info->cfg.mode & ~XT_HASHLIMIT_ALL) {
 		pr_info("Unknown mode mask %X, kernel too old?\n",
 						info->cfg.mode);
 		return -EINVAL;