Messages in this thread Patch in this message |  | | Date | Sun, 20 Oct 1996 13:16:03 -0400 (EDT) | From | Jon Lewis <> | Subject | Re: Ping with a 65510 bytes pack |
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This slightly modified version of Alan Cox's ping patch has been tested on my SMP test box. Without it, I can crash it from a Win95 box, and then softdog (I assume) reboots it. With the patch, Win95 doesn't seem able to crash it. I'm now running this patch on 5 other systems.
Is there anything other than someone trying to crash my box that would trigger the printk I added? One of our servers just logged this:
Oversized packet received from 205.229.51.6
That's one of our dialup user IP addresses. Are my own users trying to crash me, or is it just a Windows IP bug? If there's no explanation other than someone trying to crash our mail server, I'd like to terminate that account.
--- ip_fragment.c.orig Wed Aug 7 07:00:08 1996 +++ ip_fragment.c Sat Oct 19 20:33:42 1996 @@ -47,6 +47,8 @@ atomic_t ip_frag_mem = 0; /* Memory used for fragments */ +char *in_ntoa(unsigned long in); + /* * Memory Tracking Functions */ @@ -366,7 +368,7 @@ { NETDEBUG(printk("Invalid fragment list: Fragment over size.\n")); ip_free(qp); - frag_kfree_skb(skb,FREE_WRITE); + kfree_skb(skb,FREE_WRITE); ip_statistics.IpReasmFails++; return NULL; } @@ -466,6 +468,19 @@ return NULL; } } + + /* + * Attempt to construct an oversize packet. + */ + + if(ntohs(iph->tot_len)+(int)offset>65535) + { + skb->sk = NULL; + printk("Oversized packet received from %s\n",in_ntoa(qp->iph->saddr)); + frag_kfree_skb(skb, FREE_READ); + ip_statistics.IpReasmFails++; + return NULL; + } /* * Determine the position of this fragment.
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