From abe4b2c214ea83a89716288956f88b85b33bd04f Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Fri, 7 Jan 2022 10:16:44 +0300 Subject: [PATCH] Bluetooth: L2CAP: uninitialized variables in l2cap_sock_setsockopt() [ Upstream commit 2b70d4f9b20635ac328836e50d183632e1930f94 ] The "opt" variable is a u32, but on some paths only the top bytes were initialized and the others contained random stack data. Fixes: a7b75c5a8c41 ("net: pass a sockptr_t into ->setsockopt") Signed-off-by: Dan Carpenter Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin --- net/bluetooth/l2cap_sock.c | 14 ++++++++------ 1 file changed, 8 insertions(+), 6 deletions(-) diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index 251017c..d2c6785 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -903,6 +903,8 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, struct l2cap_conn *conn; int len, err = 0; u32 opt; + u16 mtu; + u8 mode; BT_DBG("sk %p", sk); @@ -1085,16 +1087,16 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, break; } - if (copy_from_sockptr(&opt, optval, sizeof(u16))) { + if (copy_from_sockptr(&mtu, optval, sizeof(u16))) { err = -EFAULT; break; } if (chan->mode == L2CAP_MODE_EXT_FLOWCTL && sk->sk_state == BT_CONNECTED) - err = l2cap_chan_reconfigure(chan, opt); + err = l2cap_chan_reconfigure(chan, mtu); else - chan->imtu = opt; + chan->imtu = mtu; break; @@ -1116,14 +1118,14 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, break; } - if (copy_from_sockptr(&opt, optval, sizeof(u8))) { + if (copy_from_sockptr(&mode, optval, sizeof(u8))) { err = -EFAULT; break; } - BT_DBG("opt %u", opt); + BT_DBG("mode %u", mode); - err = l2cap_set_mode(chan, opt); + err = l2cap_set_mode(chan, mode); if (err) break; -- 2.7.4