diff options
| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-11-18 04:20:45 +0100 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2014-01-03 04:33:33 +0000 |
| commit | 05d3c1eece356052d8119663d5415c2fcb4680d8 (patch) | |
| tree | 0dcae8323cbf05b922a3076cdb6ce88e6ab507ca /net/ipv4/udp.c | |
| parent | 9b4a3a7250034edd8c2d9096be4c082a747823a6 (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: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'net/ipv4/udp.c')
| -rw-r--r-- | net/ipv4/udp.c | 7 |
1 files changed, 1 insertions, 6 deletions
diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 549e7ae3100..239fb286570 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1174,12 +1174,6 @@ 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); @@ -1234,6 +1228,7 @@ try_again: 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); |