net: ax25: fix information leak to userland
Sometimes ax25_getname() doesn't initialize all members of fsa_digipeater
field of fsa struct, also the struct has padding bytes between
sax25_call and sax25_ndigis fields. This structure is then copied to
userland. It leads to leaking of contents of kernel stack memory.
Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 26eaebf..bb86d29 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1392,6 +1392,7 @@
ax25_cb *ax25;
int err = 0;
+ memset(fsa, 0, sizeof(fsa));
lock_sock(sk);
ax25 = ax25_sk(sk);
@@ -1403,7 +1404,6 @@
fsa->fsa_ax25.sax25_family = AF_AX25;
fsa->fsa_ax25.sax25_call = ax25->dest_addr;
- fsa->fsa_ax25.sax25_ndigis = 0;
if (ax25->digipeat != NULL) {
ndigi = ax25->digipeat->ndigi;