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From: Nickolai Zeldovich <nickolai@csail.mit.edu>
To: qemu-devel@nongnu.org
Cc: Jan Kiszka <jan.kiszka@siemens.com>,
	Nickolai Zeldovich <nickolai@csail.mit.edu>
Subject: [Qemu-devel] [PATCH] slirp: Don't crash on packets from 0.0.0.0/8.
Date: Sun, 11 Nov 2012 19:59:43 -0500	[thread overview]
Message-ID: <1352681983-23159-1-git-send-email-nickolai@csail.mit.edu> (raw)

LWIP can generate packets with a source of 0.0.0.0, which triggers an
assertion failure in arp_table_add().  Instead of crashing, simply return
to avoid adding an invalid ARP table entry.

Signed-off-by: Nickolai Zeldovich <nickolai@csail.mit.edu>
---
 slirp/arp_table.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/slirp/arp_table.c b/slirp/arp_table.c
index 5d7b8ac..3318ce9 100644
--- a/slirp/arp_table.c
+++ b/slirp/arp_table.c
@@ -38,7 +38,8 @@ void arp_table_add(Slirp *slirp, uint32_t ip_addr, uint8_t ethaddr[ETH_ALEN])
                 ethaddr[3], ethaddr[4], ethaddr[5]));
 
     /* Check 0.0.0.0/8 invalid source-only addresses */
-    assert((ip_addr & htonl(~(0xf << 28))) != 0);
+    if ((ip_addr & htonl(~(0xf << 28))) == 0)
+        return;
 
     if (ip_addr == 0xffffffff || ip_addr == broadcast_addr) {
         /* Do not register broadcast addresses */
-- 
1.7.10.4

             reply	other threads:[~2012-11-12  0:59 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-12  0:59 Nickolai Zeldovich [this message]
2012-11-12  9:37 ` [Qemu-devel] [PATCH] slirp: Don't crash on packets from 0.0.0.0/8 Jan Kiszka
2012-11-12 14:41   ` Nickolai Zeldovich
2012-11-12 16:24     ` Jan Kiszka

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