From: Koki Sanagi Date: Mon, 30 May 2011 21:48:34 +0000 (+0000) Subject: net: tracepoint of net_dev_xmit sees freed skb and causes panic X-Git-Tag: v3.0-rc2~7^2~2 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ec764bf083a6ff396234351b51fd236f53c903bf;p=pandora-kernel.git net: tracepoint of net_dev_xmit sees freed skb and causes panic Because there is a possibility that skb is kfree_skb()ed and zero cleared after ndo_start_xmit, we should not see the contents of skb like skb->len and skb->dev->name after ndo_start_xmit. But trace_net_dev_xmit does that and causes panic by NULL pointer dereference. This patch fixes trace_net_dev_xmit not to see the contents of skb directly. If you want to reproduce this panic, 1. Get tracepoint of net_dev_xmit on 2. Create 2 guests on KVM 2. Make 2 guests use virtio_net 4. Execute netperf from one to another for a long time as a network burden 5. host will panic(It takes about 30 minutes) Signed-off-by: Koki Sanagi Signed-off-by: David S. Miller --- Reading git-diff-tree failed