From 500e5c989e64489413ffde419b3d94789290a4b7 Mon Sep 17 00:00:00 2001 From: Mathias Krause Date: Wed, 15 Aug 2012 11:31:55 +0000 Subject: [PATCH] dccp: fix info leak via getsockopt(DCCP_SOCKOPT_CCID_TX_INFO) [ Upstream commit 7b07f8eb75aa3097cdfd4f6eac3da49db787381d ] 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 Cc: Gerrit Renker Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/dccp/ccids/ccid3.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/dccp/ccids/ccid3.c b/net/dccp/ccids/ccid3.c index 3d604e1349c0..4caf63f0ef05 100644 --- a/net/dccp/ccids/ccid3.c +++ b/net/dccp/ccids/ccid3.c @@ -532,6 +532,7 @@ 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; -- 2.39.5