Commit 4683f42f authored by Mathias Krause's avatar Mathias Krause Committed by David S. Miller

Bluetooth: fix possible info leak in bt_sock_recvmsg()

In case the socket is already shutting down, bt_sock_recvmsg() returns
with 0 without updating msg_namelen leading to net/socket.c leaking the
local, uninitialized sockaddr_storage variable to userland -- 128 bytes
of kernel stack memory.

Fix this by moving the msg_namelen assignment in front of the shutdown
test.

Cc: Marcel Holtmann <marcel@holtmann.org>
Cc: Gustavo Padovan <gustavo@padovan.org>
Cc: Johan Hedberg <johan.hedberg@gmail.com>
Signed-off-by: default avatarMathias Krause <minipli@googlemail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ef3313e8
...@@ -230,6 +230,8 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock, ...@@ -230,6 +230,8 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
if (flags & (MSG_OOB)) if (flags & (MSG_OOB))
return -EOPNOTSUPP; return -EOPNOTSUPP;
msg->msg_namelen = 0;
skb = skb_recv_datagram(sk, flags, noblock, &err); skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) { if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN) if (sk->sk_shutdown & RCV_SHUTDOWN)
...@@ -237,8 +239,6 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock, ...@@ -237,8 +239,6 @@ int bt_sock_recvmsg(struct kiocb *iocb, struct socket *sock,
return err; return err;
} }
msg->msg_namelen = 0;
copied = skb->len; copied = skb->len;
if (len < copied) { if (len < copied) {
msg->msg_flags |= MSG_TRUNC; msg->msg_flags |= MSG_TRUNC;
......
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