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>
This commit is contained in:

committed by
David S. Miller

parent
bcd081a3ae
commit
bceaa90240
@@ -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);
|
||||
|
Reference in New Issue
Block a user