Re: [PATCH net-2.6] L2TP: Fix potential memory corruption in pppol2tp_recvmsg()

From: James Chapman <jchapman@katalix.com>
Date: Tue, 10 Jun 2008 13:34:24 +0100

This patch fixes a potential memory corruption in
pppol2tp_recvmsg(). If skb->len is bigger than the caller's buffer
length, memcpy_toiovec() will go into unintialized data on the kernel
heap, interpret it as an iovec and start modifying memory.

The fix is to change the memcpy_toiovec() call to
skb_copy_datagram_iovec() so that paged packets (rare for PPPOL2TP)
are handled properly. Also check that the caller's buffer is big
enough for the data and set the MSG_TRUNC flag if it is not so.

Reported-by: Ilja <redacted>
Signed-off-by: James Chapman <jchapman@katalix.com>

Applied, thanks.

Please see:

http://marc.info/?l=linux-netdev&m=121262022428660&w=2

for a description of how I would like folks to format their
commit header lines for networking changes nowadays.  I fixed
it up by hand for you this time.

A candidate for -stable?

Yes, and I've queued it up for such.