diff options
| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-11-17 22:20:45 -0500 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-11-18 15:12:03 -0500 |
| commit | bceaa90240b6019ed73b49965eac7d167610be69 (patch) | |
| tree | f68c10948efff147a7b987369f1e720ad76f411b /net/phonet | |
| parent | bcd081a3aef1f7f3786067ae8dd26aaa1cf85153 (diff) | |
inet: prevent leakage of uninitialized memory to user in recv syscalls
Only update *addr_len when we actually fill in sockaddr, otherwise we
can return uninitialized memory from the stack to the caller in the
recvfrom, recvmmsg and recvmsg syscalls. Drop the the (addr_len == NULL)
checks because we only get called with a valid addr_len pointer either
from sock_common_recvmsg or inet_recvmsg.
If a blocking read waits on a socket which is concurrently shut down we
now return zero and set msg_msgnamelen to 0.
Reported-by: mpb <mpb.mail@gmail.com>
Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/phonet')
| -rw-r--r-- | net/phonet/datagram.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/net/phonet/datagram.c b/net/phonet/datagram.c index 12c30f3e643e..38946b26e471 100644 --- a/net/phonet/datagram.c +++ b/net/phonet/datagram.c | |||
| @@ -139,9 +139,6 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk, | |||
| 139 | MSG_CMSG_COMPAT)) | 139 | MSG_CMSG_COMPAT)) |
| 140 | goto out_nofree; | 140 | goto out_nofree; |
| 141 | 141 | ||
| 142 | if (addr_len) | ||
| 143 | *addr_len = sizeof(sa); | ||
| 144 | |||
| 145 | skb = skb_recv_datagram(sk, flags, noblock, &rval); | 142 | skb = skb_recv_datagram(sk, flags, noblock, &rval); |
| 146 | if (skb == NULL) | 143 | if (skb == NULL) |
| 147 | goto out_nofree; | 144 | goto out_nofree; |
| @@ -162,8 +159,10 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk, | |||
| 162 | 159 | ||
| 163 | rval = (flags & MSG_TRUNC) ? skb->len : copylen; | 160 | rval = (flags & MSG_TRUNC) ? skb->len : copylen; |
| 164 | 161 | ||
| 165 | if (msg->msg_name != NULL) | 162 | if (msg->msg_name != NULL) { |
| 166 | memcpy(msg->msg_name, &sa, sizeof(struct sockaddr_pn)); | 163 | memcpy(msg->msg_name, &sa, sizeof(sa)); |
| 164 | *addr_len = sizeof(sa); | ||
| 165 | } | ||
| 167 | 166 | ||
| 168 | out: | 167 | out: |
| 169 | skb_free_datagram(sk, skb); | 168 | skb_free_datagram(sk, skb); |