Messages in this thread | | | Date | Tue, 22 Jul 2014 10:42:14 +0300 | From | Dan Carpenter <> | Subject | Re: [PATCH 3/5] net/netfilter/ipvs/ip_vs_ctl.c: drop argument range check just before the check for equality |
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On Mon, Jul 21, 2014 at 11:01:56PM +0300, Julian Anastasov wrote: > @@ -2333,13 +2339,12 @@ do_ip_vs_set_ctl(struct sock *sk, int cmd, void __user *user, unsigned int len) > struct ip_vs_dest_user_kern udest; > struct netns_ipvs *ipvs = net_ipvs(net); > > + BUILD_BUG_ON(sizeof(arg) > 256);
256 is off-by-one because u8 ranges from 0-255 so we are never able to copy 256 bytes into the "arg" buffer.
> - if (copylen > 128) > + if (*len < (int) copylen || *len < 0) { > + pr_err("get_ctl: len %d < %u\n", *len, copylen);
Don't let users flood dmesg. Just return an error. (This can be triggered by non-root as well).
> return -EINVAL; > + }
regards, dan carpenter
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