3.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Mathias Krause <minipli@xxxxxxxxxxxxxx>
[ Upstream commit 4683f42fde3977bdb4e8a09622788cc8b5313778 ]
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.
Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Gustavo Padovan <gustavo@xxxxxxxxxxx>
Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/bluetooth/af_bluetooth.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/net/bluetooth/af_bluetooth.c
+++ b/net/bluetooth/af_bluetooth.c
@@ -240,6 +240,8 @@ int bt_sock_recvmsg(struct kiocb *iocb,
if (flags & (MSG_OOB))
return -EOPNOTSUPP;
+ msg->msg_namelen = 0;
+
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb) {
if (sk->sk_shutdown & RCV_SHUTDOWN)
@@ -247,8 +249,6 @@ int bt_sock_recvmsg(struct kiocb *iocb,
return err;
}
- msg->msg_namelen = 0;
-
copied = skb->len;
if (len < copied) {
msg->msg_flags |= MSG_TRUNC;
--
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