From bef2b3da0857396fc79f2f7be0863ce4e4b63f38 Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Thu, 15 Oct 2015 12:25:00 -0500 Subject: net: add length argument to skb_copy_and_csum_datagram_iovec Without this length argument, we can read past the end of the iovec in memcpy_toiovec because we have no way of knowing the total length of the iovec's buffers. This is needed for stable kernels where 89c22d8c3b27 ("net: Fix skb csum races when peeking") has been backported but that don't have the ioviter conversion, which is almost all the stable trees <= 3.18. This also fixes a kernel crash for NFS servers when the client uses -onfsvers=3,proto=udp to mount the export. Change-Id: I1865e3d7a1faee42a5008a9ad58c4d3323ea4bab Signed-off-by: Sabrina Dubroca Reviewed-by: Hannes Frederic Sowa (cherry picked from commit c91234366e4cfd4f70c73e7d79ede92a6e462a88) --- include/linux/skbuff.h | 3 ++- net/core/datagram.c | 6 +++++- net/ipv4/tcp_input.c | 2 +- net/ipv4/udp.c | 2 +- net/ipv6/raw.c | 2 +- net/ipv6/udp.c | 3 ++- net/rxrpc/ar-recvmsg.c | 3 ++- 7 files changed, 14 insertions(+), 7 deletions(-) diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 7b547c235d9..4fbf56de011 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -1857,7 +1857,8 @@ extern int skb_copy_datagram_iovec(const struct sk_buff *from, int size); extern int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, int hlen, - struct iovec *iov); + struct iovec *iov, + int len); extern int skb_copy_datagram_from_iovec(struct sk_buff *skb, int offset, const struct iovec *from, diff --git a/net/core/datagram.c b/net/core/datagram.c index 18ac112ea7a..aaf4559b364 100644 --- a/net/core/datagram.c +++ b/net/core/datagram.c @@ -672,6 +672,7 @@ EXPORT_SYMBOL(__skb_checksum_complete); * @skb: skbuff * @hlen: hardware length * @iov: io vector + * @len: amount of data to copy from skb to iov * * Caller _must_ check that skb will fit to this iovec. * @@ -681,11 +682,14 @@ EXPORT_SYMBOL(__skb_checksum_complete); * can be modified! */ int skb_copy_and_csum_datagram_iovec(struct sk_buff *skb, - int hlen, struct iovec *iov) + int hlen, struct iovec *iov, int len) { __wsum csum; int chunk = skb->len - hlen; + if (chunk > len) + chunk = len; + if (!chunk) return 0; diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index a60f38673de..71cbf7a40a0 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -5131,7 +5131,7 @@ static int tcp_copy_to_iovec(struct sock *sk, struct sk_buff *skb, int hlen) err = skb_copy_datagram_iovec(skb, hlen, tp->ucopy.iov, chunk); else err = skb_copy_and_csum_datagram_iovec(skb, hlen, - tp->ucopy.iov); + tp->ucopy.iov, chunk); if (!err) { tp->ucopy.len -= chunk; diff --git a/net/ipv4/udp.c b/net/ipv4/udp.c index 05b0523096e..43c3a2cbf17 100644 --- a/net/ipv4/udp.c +++ b/net/ipv4/udp.c @@ -1210,7 +1210,7 @@ try_again: else { err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), - msg->msg_iov); + msg->msg_iov, copied); if (err == -EINVAL) goto csum_copy_err; diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c index 0a7eae06157..40147c998b6 100644 --- a/net/ipv6/raw.c +++ b/net/ipv6/raw.c @@ -481,7 +481,7 @@ static int rawv6_recvmsg(struct kiocb *iocb, struct sock *sk, goto csum_copy_err; err = skb_copy_datagram_iovec(skb, 0, msg->msg_iov, copied); } else { - err = skb_copy_and_csum_datagram_iovec(skb, 0, msg->msg_iov); + err = skb_copy_and_csum_datagram_iovec(skb, 0, msg->msg_iov, copied); if (err == -EINVAL) goto csum_copy_err; } diff --git a/net/ipv6/udp.c b/net/ipv6/udp.c index 2e3a22d8b3a..3d39f3005e9 100644 --- a/net/ipv6/udp.c +++ b/net/ipv6/udp.c @@ -386,7 +386,8 @@ try_again: err = skb_copy_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov, copied ); else { - err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), msg->msg_iov); + err = skb_copy_and_csum_datagram_iovec(skb, sizeof(struct udphdr), + msg->msg_iov, copied); if (err == -EINVAL) goto csum_copy_err; } diff --git a/net/rxrpc/ar-recvmsg.c b/net/rxrpc/ar-recvmsg.c index 0c65013e3bf..280b9ea6db2 100644 --- a/net/rxrpc/ar-recvmsg.c +++ b/net/rxrpc/ar-recvmsg.c @@ -181,7 +181,8 @@ int rxrpc_recvmsg(struct kiocb *iocb, struct socket *sock, msg->msg_iov, copy); } else { ret = skb_copy_and_csum_datagram_iovec(skb, offset, - msg->msg_iov); + msg->msg_iov, + copy); if (ret == -EINVAL) goto csum_copy_error; } -- cgit v1.2.3