From 01db403cf99f739f86903314a489fb420e0e254f Mon Sep 17 00:00:00 2001
From: "David S. Miller" <davem@davemloft.net>
Date: Mon, 27 Sep 2010 20:24:54 -0700
Subject: [PATCH] tcp: Fix >4GB writes on 64-bit.
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Fixes kernel bugzilla #16603
tcp_sendmsg() truncates iov_len to an 'int' which a 4GB write to write
zero bytes, for example.
There is also the problem higher up of how verify_iovec() works. It
wants to prevent the total length from looking like an error return
value.
However it does this using 'int', but syscalls return 'long' (and
thus signed 64-bit on 64-bit machines). So it could trigger
false-positives on 64-bit as written. So fix it to use 'long'.
Reported-by: Olaf Bonorden <bono@onlinehome.de>
Reported-by: Daniel Büse <dbuese@gmx.de>
Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/linux/socket.h | 2 +-
net/core/iovec.c | 5 +++--
net/ipv4/tcp.c | 2 +-
3 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/include/linux/socket.h b/include/linux/socket.h
index a2fada9becb6..a8f56e1ec760 100644
--- a/include/linux/socket.h
+++ b/include/linux/socket.h
@@ -322,7 +322,7 @@ extern int csum_partial_copy_fromiovecend(unsigned char *kdata,
int offset,
unsigned int len, __wsum *csump);
-extern int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address, int mode);
+extern long verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address, int mode);
extern int memcpy_toiovec(struct iovec *v, unsigned char *kdata, int len);
extern int memcpy_toiovecend(const struct iovec *v, unsigned char *kdata,
int offset, int len);
diff --git a/net/core/iovec.c b/net/core/iovec.c
index 1cd98df412df..e6b133b77ccb 100644
--- a/net/core/iovec.c
+++ b/net/core/iovec.c
@@ -35,9 +35,10 @@
* in any case.
*/
-int verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address, int mode)
+long verify_iovec(struct msghdr *m, struct iovec *iov, struct sockaddr *address, int mode)
{
- int size, err, ct;
+ int size, ct;
+ long err;
if (m->msg_namelen) {
if (mode == VERIFY_READ) {
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index 95d75d443927..f115ea68a4ef 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -943,7 +943,7 @@ int tcp_sendmsg(struct kiocb *iocb, struct sock *sk, struct msghdr *msg,
sg = sk->sk_route_caps & NETIF_F_SG;
while (--iovlen >= 0) {
- int seglen = iov->iov_len;
+ size_t seglen = iov->iov_len;
unsigned char __user *from = iov->iov_base;
iov++;
--
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