From: Jason Wang Date: Wed, 10 Jul 2013 05:43:27 +0000 (+0800) Subject: tuntap: correctly linearize skb when zerocopy is used X-Git-Tag: v3.11-rc1~5^2~30 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3dd5c3308e8b671e8e8882ba972f51cefbe9fd0d;p=pandora-kernel.git tuntap: correctly linearize skb when zerocopy is used Userspace may produce vectors greater than MAX_SKB_FRAGS. When we try to linearize parts of the skb to let the rest of iov to be fit in the frags, we need count copylen into linear when calling tun_alloc_skb() instead of partly counting it into data_len. Since this breaks zerocopy_sg_from_iovec() since its inner counter assumes nr_frags should be zero at beginning. This cause nr_frags to be increased wrongly without setting the correct frags. This bug were introduced from 0690899b4d4501b3505be069b9a687e68ccbe15b (tun: experimental zero copy tx support) Cc: Michael S. Tsirkin Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller --- Reading git-diff-tree failed