From: Jason Wang Date: Wed, 13 Nov 2013 06:00:39 +0000 (+0800) Subject: tuntap: limit head length of skb allocated X-Git-Tag: v3.13-rc1~33^2~51 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=96f8d9ecf227638c89f98ccdcdd50b569891976c;p=pandora-kernel.git tuntap: limit head length of skb allocated We currently use hdr_len as a hint of head length which is advertised by guest. But when guest advertise a very big value, it can lead to an 64K+ allocating of kmalloc() which has a very high possibility of failure when host memory is fragmented or under heavy stress. The huge hdr_len also reduce the effect of zerocopy or even disable if a gso skb is linearized in guest. To solves those issues, this patch introduces an upper limit (PAGE_SIZE) of the head, which guarantees an order 0 allocation each time. Cc: Stefan Hajnoczi Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Signed-off-by: David S. Miller --- Reading git-diff-tree failed