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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>
This commit is contained in:
David S. Miller 2010-09-27 20:24:54 -07:00
parent 0b20406cda
commit 01db403cf9
3 changed files with 5 additions and 4 deletions
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2
include/linux/socket.h
View file

@ -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);

5
net/core/iovec.c
View file

@ -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) {

2
net/ipv4/tcp.c
View file

@ -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++;