| Message ID | 20200723144957.GA293102@mwanda |
|---|---|
| State | Accepted |
| Delegated to: | David Miller |
| Headers | show |
| Series | [net] AX.25: Prevent integer overflows in connect and sendmsg | expand |
From: Dan Carpenter <dan.carpenter@oracle.com> Date: Thu, 23 Jul 2020 17:49:57 +0300 > 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: 8885bb0621f0 ("AX.25: Prevent out-of-bounds read in ax25_sendmsg()") > Fixes: 2f2a7ffad5c6 ("AX.25: Fix out-of-bounds read in ax25_connect()") > Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Applied, thanks Dan.
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index 0862fe49d434..dec3f35467c9 100644 --- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -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;
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: 8885bb0621f0 ("AX.25: Prevent out-of-bounds read in ax25_sendmsg()") Fixes: 2f2a7ffad5c6 ("AX.25: Fix out-of-bounds read in ax25_connect()") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> --- From code review. Not tested. It should be harmless though. net/ax25/af_ax25.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)