Commit 01db403c authored by David S. Miller's avatar David S. Miller
Browse files

tcp: Fix >4GB writes on 64-bit. 



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: default avatarOlaf Bonorden <bono@onlinehome.de>
Reported-by: default avatarDaniel Büse <dbuese@gmx.de>
Reported-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 0b20406c

include/linux/socket.h

+1 −1
Original line number Diff line number Diff line
@@ -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);

net/core/iovec.c

+3 −2
Original line number Diff line number Diff line
@@ -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) {

net/ipv4/tcp.c

+1 −1
Original line number Diff line number Diff line
@@ -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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