ax25: fix info leak via msg_name in ax25_recvmsg()
[ Upstream commit ef3313e84acbf349caecae942ab3ab731471f1a1 ]
When msg_namelen is non-zero the sockaddr info gets filled out, as
requested, but the code fails to initialize the padding bytes of struct
sockaddr_ax25 inserted by the compiler for alignment. Additionally the
msg_namelen value is updated to sizeof(struct full_sockaddr_ax25) but is
not always filled up to this size.
Both issues lead to the fact that the code will leak uninitialized
kernel stack bytes in net/socket.c.
Fix both issues by initializing the memory with memset(0).
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 6ab35a2..ca8308a 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1649,6 +1649,7 @@
ax25_address src;
const unsigned char *mac = skb_mac_header(skb);
+ memset(sax, 0, sizeof(struct full_sockaddr_ax25));
ax25_addr_parse(mac + 1, skb->data - mac - 1, &src, NULL,
&digi, NULL, NULL);
sax->sax25_family = AF_AX25;