From: Ben McKeegan Date: Mon, 16 Nov 2009 03:44:25 +0000 (+0000) Subject: ppp: fix BUG on non-linear SKB (multilink receive) X-Git-Tag: v2.6.32-rc8~10^2~6 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=82b3cc1a2f5e46300a9dec4a8cc8106dc20a4c23;p=pandora-kernel.git ppp: fix BUG on non-linear SKB (multilink receive) PPP does not correctly call pskb_may_pull() on all necessary receive paths before reading the PPP protocol, thus causing PPP to report seemingly random 'unsupported protocols' and eventually trigger BUG_ON(skb->len < skb->data_len) in skb_pull_rcsum() when receiving multilink protocol in non-linear skbs. ppp_receive_nonmp_frame() does not call pskb_may_pull() before reading the protocol number. For the non-mp receive path this is not a problem, as this check is done in ppp_receive_frame(). For the mp receive path, ppp_mp_reconstruct() usually copies the data into a new linear skb. However, in the case where the frame is made up of a single mp fragment, the mp header is pulled and the existing skb used. This skb was then passed to ppp_receive_nonmp_frame() without checking if the encapsulated protocol header could safely be read. Signed-off-by: Ben McKeegan Signed-off-by: David S. Miller --- Reading git-diff-tree failed