diff options
author | Ben McKeegan <ben@netservers.co.uk> | 2009-11-16 03:44:25 +0000 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2009-11-16 23:51:34 -0800 |
commit | 82b3cc1a2f5e46300a9dec4a8cc8106dc20a4c23 (patch) | |
tree | 1388b3a52e05a690a1084c06799fb934562901b2 /drivers/isdn/hardware/mISDN | |
parent | c0e1f68bce454d244e2eea6b0ab7b3a217c673d2 (diff) |
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 <ben@netservers.co.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/isdn/hardware/mISDN')
0 files changed, 0 insertions, 0 deletions