Commit bceaa902 authored by Hannes Frederic Sowa's avatar Hannes Frederic Sowa Committed by David S. Miller

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: 's avatarmpb <mpb.mail@gmail.com>
Suggested-by: 's avatarEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: 's avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: 's avatarDavid S. Miller <davem@davemloft.net>
parent bcd081a3
......@@ -315,9 +315,8 @@ static int dgram_recvmsg(struct kiocb *iocb, struct sock *sk,
if (saddr) {
saddr->family = AF_IEEE802154;
saddr->addr = mac_cb(skb)->sa;
}
if (addr_len)
*addr_len = sizeof(*saddr);
}
if (flags & MSG_TRUNC)
copied = skb->len;
......
......@@ -830,8 +830,6 @@ 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;
......@@ -841,13 +839,6 @@ 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);
......@@ -877,11 +868,13 @@ 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);
......@@ -890,17 +883,19 @@ 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);
......
......@@ -696,9 +696,6 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
if (flags & MSG_OOB)
goto out;
if (addr_len)
*addr_len = sizeof(*sin);
if (flags & MSG_ERRQUEUE) {
err = ip_recv_error(sk, msg, len);
goto out;
......@@ -726,6 +723,7 @@ static int raw_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
sin->sin_port = 0;
memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (inet->cmsg_flags)
ip_cmsg_recv(msg, skb);
......
......@@ -1235,12 +1235,6 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
int is_udplite = IS_UDPLITE(sk);
bool slow;
/*
* Check any passed addresses
*/
if (addr_len)
*addr_len = sizeof(*sin);
if (flags & MSG_ERRQUEUE)
return ip_recv_error(sk, msg, len);
......@@ -1302,6 +1296,7 @@ int udp_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
sin->sin_port = udp_hdr(skb)->source;
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
memset(sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (inet->cmsg_flags)
ip_cmsg_recv(msg, skb);
......
......@@ -465,9 +465,6 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
if (flags & MSG_OOB)
return -EOPNOTSUPP;
if (addr_len)
*addr_len=sizeof(*sin6);
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len);
......@@ -506,6 +503,7 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk,
sin6->sin6_flowinfo = 0;
sin6->sin6_scope_id = ipv6_iface_scope_id(&sin6->sin6_addr,
IP6CB(skb)->iif);
*addr_len = sizeof(*sin6);
}
sock_recv_ts_and_drops(msg, sk, skb);
......
......@@ -392,9 +392,6 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
int is_udp4;
bool slow;
if (addr_len)
*addr_len = sizeof(struct sockaddr_in6);
if (flags & MSG_ERRQUEUE)
return ipv6_recv_error(sk, msg, len);
......@@ -480,7 +477,7 @@ int udpv6_recvmsg(struct kiocb *iocb, struct sock *sk,
ipv6_iface_scope_id(&sin6->sin6_addr,
IP6CB(skb)->iif);
}
*addr_len = sizeof(*sin6);
}
if (is_udp4) {
if (inet->cmsg_flags)
......
......@@ -518,9 +518,6 @@ static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m
if (flags & MSG_OOB)
goto out;
if (addr_len)
*addr_len = sizeof(*sin);
skb = skb_recv_datagram(sk, flags, noblock, &err);
if (!skb)
goto out;
......@@ -543,6 +540,7 @@ static int l2tp_ip_recvmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *m
sin->sin_addr.s_addr = ip_hdr(skb)->saddr;
sin->sin_port = 0;
memset(&sin->sin_zero, 0, sizeof(sin->sin_zero));
*addr_len = sizeof(*sin);
}
if (inet->cmsg_flags)
ip_cmsg_recv(msg, skb);
......
......@@ -139,9 +139,6 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk,
MSG_CMSG_COMPAT))
goto out_nofree;
if (addr_len)
*addr_len = sizeof(sa);
skb = skb_recv_datagram(sk, flags, noblock, &rval);
if (skb == NULL)
goto out_nofree;
......@@ -162,8 +159,10 @@ static int pn_recvmsg(struct kiocb *iocb, struct sock *sk,
rval = (flags & MSG_TRUNC) ? skb->len : copylen;
if (msg->msg_name != NULL)
memcpy(msg->msg_name, &sa, sizeof(struct sockaddr_pn));
if (msg->msg_name != NULL) {
memcpy(msg->msg_name, &sa, sizeof(sa));
*addr_len = sizeof(sa);
}
out:
skb_free_datagram(sk, skb);
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment