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.

[cherry-pick of net-next bceaa90240b6019ed73b49965eac7d167610be69]

Bug: 28347599
Change-Id: Id292aa64697c5b5bccc8e0f7d9236b519454ef27
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>
Git-commit: 1ad7f4b67337194d668fd8983fad0c84eff00fac
Git-repo: https://android.googlesource.com/kernel/common.git
Signed-off-by: Srinivasarao P <spathi@codeaurora.org>
This commit is contained in:
Hannes Frederic Sowa 2013-11-18 04:20:45 +01:00 committed by syphyr
parent a33afc1b0e
commit bd9cd435ab
1 changed files with 9 additions and 15 deletions

View File

@ -859,8 +859,6 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
{
struct inet_sock *isk = inet_sk(sk);
int family = sk->sk_family;
struct sockaddr_in *sin;
struct sockaddr_in6 *sin6;
struct sk_buff *skb;
int copied, err;
@ -870,13 +868,6 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if (flags & MSG_OOB)
goto out;
if (addr_len) {
if (family == AF_INET)
*addr_len = sizeof(*sin);
else if (family == AF_INET6 && addr_len)
*addr_len = sizeof(*sin6);
}
if (flags & MSG_ERRQUEUE) {
if (family == AF_INET) {
return ip_recv_error(sk, msg, len, addr_len);
@ -907,12 +898,14 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
/* Copy the address and add cmsg data. */
if (family == AF_INET) {
sin = (struct sockaddr_in *) msg->msg_name;
struct sockaddr_in *sin = (struct sockaddr_in *)msg->msg_name;
if (sin) {
sin->sin_family = AF_INET;
sin->sin_port = 0 /* skb->h.uh->source */;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (isk->cmsg_flags)
@ -922,19 +915,20 @@ int ping_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
} else if (family == AF_INET6) {
struct ipv6_pinfo *np = inet6_sk(sk);
struct ipv6hdr *ip6 = ipv6_hdr(skb);
sin6 = (struct sockaddr_in6 *) msg->msg_name;
struct sockaddr_in6 *sin6 =
(struct sockaddr_in6 *)msg->msg_name;
if (sin6) {
sin6->sin6_family = AF_INET6;
sin6->sin6_port = 0;
sin6->sin6_addr = ip6->saddr;
sin6->sin6_flowinfo = 0;
if (np->sndflow)
sin6->sin6_flowinfo = ip6_flowinfo(ip6);
sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
IP6CB(skb)->iif);
sin6->sin6_scope_id =
ipv6_iface_scope_id(&sin6->sin6_addr,
IP6CB(skb)->iif);
*addr_len = sizeof(*sin6);
}
if (inet6_sk(sk)->rxopt.all)