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authorAl Viro <viro@zeniv.linux.org.uk>2018-10-08 06:22:35 -0400
committerDavid S. Miller <davem@davemloft.net>2018-10-08 10:33:35 -0700
commit2f0c982df7b146f9aa695ede91b48392ab4c3217 (patch)
tree053c7a370765fcf2f8afa60dffef94d29e86b1c2 /net/sched
parent27594ec4b6a7035450ba43624d1648cbd2c0aaea (diff)
downloadlinux-2f0c982df7b146f9aa695ede91b48392ab4c3217.tar.gz
net: sched: cls_u32: make sure that divisor is a power of 2
Tested by modifying iproute2 to allow sending a divisor > 255

Tested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/sched')
-rw-r--r--net/sched/cls_u32.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index 3357331a80a2..ce55eea448a0 100644
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -994,7 +994,11 @@ static int u32_change(struct net *net, struct sk_buff *in_skb,
 	if (tb[TCA_U32_DIVISOR]) {
 		unsigned int divisor = nla_get_u32(tb[TCA_U32_DIVISOR]);
 
-		if (--divisor > 0x100) {
+		if (!is_power_of_2(divisor)) {
+			NL_SET_ERR_MSG_MOD(extack, "Divisor is not a power of 2");
+			return -EINVAL;
+		}
+		if (divisor-- > 0x100) {
 			NL_SET_ERR_MSG_MOD(extack, "Exceeded maximum 256 hash buckets");
 			return -EINVAL;
 		}