From: Dan Carpenter <dan.carpenter@oracle.com> stable inclusion from stable-v5.10.94 commit 9d6350cf8e5aa6acf1a7c72f7a9ca000e5fa447d bugzilla: https://gitee.com/openeuler/kernel/issues/I531X9 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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 <dan.carpenter@oracle.com> Signed-off-by: Marcel Holtmann <marcel@holtmann.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> Acked-by: Xie XiuQi <xiexiuqi@huawei.com> --- 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 251017c69ab7..d2c678520599 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; -- 2.20.1