diff options
| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-11-18 04:20:45 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-12-08 07:29:13 -0800 |
| commit | 7a9b8e64a5706d62d5a5ab54fe3d0320845b1d4a (patch) | |
| tree | 11cebc8844dde01cce28d913a9340953b1cd5e96 /net/ipv4/ping.c | |
| parent | d902e2c30aeba8d9d76d9c7845f4b9833f7c336d (diff) | |
inet: prevent leakage of uninitialized memory to user in recv syscalls
[ Upstream commit bceaa90240b6019ed73b49965eac7d167610be69 ]
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/ipv4/ping.c')
| -rw-r--r-- | net/ipv4/ping.c | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/net/ipv4/ping.c b/net/ipv4/ping.c index d7d9882d4cae..92fb6ff92717 100644 --- a/net/ipv4/ping.c +++ b/net/ipv4/ping.c @@ -827,8 +827,6 @@ 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; @@ -838,13 +836,6 @@ 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); @@ -874,11 +865,13 @@ 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; + 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) ip_cmsg_recv(msg, skb); @@ -887,17 +880,19 @@ 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; + 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); + *addr_len = sizeof(*sin6); if (inet6_sk(sk)->rxopt.all) pingv6_ops.ip6_datagram_recv_ctl(sk, msg, skb); |