net: Cap number of elements for sendmmsg

To limit the amount of time we can spend in sendmmsg, cap the
number of elements to UIO_MAXIOV (currently 1024).

For error handling an application using sendmmsg needs to retry at
the first unsent message, so capping is simpler and requires less
application logic than returning EINVAL.

Signed-off-by: Anton Blanchard <anton@samba.org>
Cc: stable <stable@kernel.org> [3.0+]
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Anton Blanchard 2011-08-04 14:07:39 +00:00 committed by David S. Miller
parent 728ffb86f1
commit 98382f419f

View file

@ -1999,6 +1999,9 @@ int __sys_sendmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
struct compat_mmsghdr __user *compat_entry;
struct msghdr msg_sys;
if (vlen > UIO_MAXIOV)
vlen = UIO_MAXIOV;
datagrams = 0;
sock = sockfd_lookup_light(fd, &err, &fput_needed);