[ 49/49] netfilter: ipset: Fix serious failure in CIDR tracking

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Oliver Smith <oliver@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>

commit 2cf55125c64d64cc106e204d53b107094762dfdf upstream.

This fixes a serious bug affecting all hash types with a net element -
specifically, if a CIDR value is deleted such that none of the same size
exist any more, all larger (less-specific) values will then fail to
match. Adding back any prefix with a CIDR equal to or more specific than
the one deleted will fix it.

Steps to reproduce:
ipset -N test hash:net
ipset -A test 1.1.0.0/16
ipset -A test 2.2.2.0/24
ipset -T test 1.1.1.1           #1.1.1.1 IS in set
ipset -D test 2.2.2.0/24
ipset -T test 1.1.1.1           #1.1.1.1 IS NOT in set

This is due to the fact that the nets counter was unconditionally
decremented prior to the iteration that shifts up the entries. Now, we
first check if there is a proceeding entry and if not, decrement it and
return. Otherwise, we proceed to iterate and then zero the last element,
which, in most cases, will already be zero.

Signed-off-by: Oliver Smith <oliver@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 net/netfilter/ipset/ip_set_hash_gen.h |   26 +++++++++++++++-----------
 1 file changed, 15 insertions(+), 11 deletions(-)

--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -325,18 +325,22 @@ mtype_add_cidr(struct htype *h, u8 cidr,
 static void
 mtype_del_cidr(struct htype *h, u8 cidr, u8 nets_length)
 {
-	u8 i, j;
+	u8 i, j, net_end = nets_length - 1;
 
-	for (i = 0; i < nets_length - 1 && h->nets[i].cidr != cidr; i++)
-		;
-	h->nets[i].nets--;
-
-	if (h->nets[i].nets != 0)
-		return;
-
-	for (j = i; j < nets_length - 1 && h->nets[j].nets; j++) {
-		h->nets[j].cidr = h->nets[j + 1].cidr;
-		h->nets[j].nets = h->nets[j + 1].nets;
+	for (i = 0; i < nets_length; i++) {
+	        if (h->nets[i].cidr != cidr)
+	                continue;
+                if (h->nets[i].nets > 1 || i == net_end ||
+                    h->nets[i + 1].nets == 0) {
+                        h->nets[i].nets--;
+                        return;
+                }
+                for (j = i; j < net_end && h->nets[j].nets; j++) {
+		        h->nets[j].cidr = h->nets[j + 1].cidr;
+		        h->nets[j].nets = h->nets[j + 1].nets;
+                }
+                h->nets[j].nets = 0;
+                return;
 	}
 }
 #endif


--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]