dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO)

[ Upstream commit 7b07f8eb75 ]

The CCID3 code fails to initialize the trailing padding bytes of struct
tfrc_tx_info added for alignment on 64 bit architectures. It that for
potentially leaks four bytes kernel stack via the getsockopt() syscall.
Add an explicit memset(0) before filling the structure to avoid the
info leak.

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mathias Krause 2012-08-15 11:31:55 +00:00 committed by Greg Kroah-Hartman
parent 00ed5b8f39
commit 59039dc90b

View file

@ -531,6 +531,7 @@ static int ccid3_hc_tx_getsockopt(struct sock *sk, const int optname, int len,
case DCCP_SOCKOPT_CCID_TX_INFO:
if (len < sizeof(tfrc))
return -EINVAL;
memset(&tfrc, 0, sizeof(tfrc));
tfrc.tfrctx_x = hc->tx_x;
tfrc.tfrctx_x_recv = hc->tx_x_recv;
tfrc.tfrctx_x_calc = hc->tx_x_calc;