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| author | Hannes Frederic Sowa <hannes@stressinduktion.org> | 2013-11-18 04:20:45 +0100 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-11-18 15:12:03 -0500 |
| commit | bceaa90240b6019ed73b49965eac7d167610be69 (patch) | |
| tree | f68c10948efff147a7b987369f1e720ad76f411b /net/ipv6/udp.c | |
| parent | bcd081a3aef1f7f3786067ae8dd26aaa1cf85153 (diff) | |
| download | lwn-bceaa90240b6019ed73b49965eac7d167610be69.tar.gz lwn-bceaa90240b6019ed73b49965eac7d167610be69.zip | |
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>
Diffstat (limited to 'net/ipv6/udp.c')
| -rw-r--r-- | net/ipv6/udp.c | 5 |
1 files changed, 1 insertions, 4 deletions
diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index f3893e897f72..81eb8cf8389b 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -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 @@ try_again: ipv6_iface_scope_id(&sin6->sin6_addr, IP6CB(skb)->iif); } - + *addr_len = sizeof(*sin6); } if (is_udp4) { if (inet->cmsg_flags) |