AX.25: Prevent integer overflows in connect and sendmsg

We recently added some bounds checking in ax25_connect() and
ax25_sendmsg() and we so we removed the AX25_MAX_DIGIS checks because
they were no longer required.

Unfortunately, I believe they are required to prevent integer overflows
so I have added them back.

Fixes: 8885bb0621 ("AX.25: Prevent out-of-bounds read in ax25_sendmsg()")
Fixes: 2f2a7ffad5 ("AX.25: Fix out-of-bounds read in ax25_connect()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Dan Carpenter 2020-07-23 17:49:57 +03:00 committed by David S. Miller
parent e6827d1abd
commit 17ad73e941

View File

@ -1188,6 +1188,7 @@ static int __must_check ax25_connect(struct socket *sock,
fsa->fsa_ax25.sax25_ndigis != 0) {
/* Valid number of digipeaters ? */
if (fsa->fsa_ax25.sax25_ndigis < 1 ||
fsa->fsa_ax25.sax25_ndigis > AX25_MAX_DIGIS ||
addr_len < sizeof(struct sockaddr_ax25) +
sizeof(ax25_address) * fsa->fsa_ax25.sax25_ndigis) {
err = -EINVAL;
@ -1509,7 +1510,9 @@ static int ax25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)usax;
/* Valid number of digipeaters ? */
if (usax->sax25_ndigis < 1 || addr_len < sizeof(struct sockaddr_ax25) +
if (usax->sax25_ndigis < 1 ||
usax->sax25_ndigis > AX25_MAX_DIGIS ||
addr_len < sizeof(struct sockaddr_ax25) +
sizeof(ax25_address) * usax->sax25_ndigis) {
err = -EINVAL;
goto out;