From: Al Viro <viro@ZenIV.linux.org.uk>
To: David Miller <davem@redhat.com>
Cc: herbert@gondor.apana.org.au, netdev@vger.kernel.org,
linux-kernel@vger.kernel.org, bcrl@kvack.org
Subject: Re: [PATCH 1/4] inet: Add skb_copy_datagram_iter
Date: Fri, 7 Nov 2014 22:35:58 +0000 [thread overview]
Message-ID: <20141107223558.GD7996@ZenIV.linux.org.uk> (raw)
In-Reply-To: <20141107223153.GC7996@ZenIV.linux.org.uk>
On Fri, Nov 07, 2014 at 10:31:53PM +0000, Al Viro wrote:
> On Fri, Nov 07, 2014 at 10:11:14PM +0000, Al Viro wrote:
>
> > I'm looking through the tree right now; so far it looks like we can just
> > move those suckers to the point where we validate iovec and lose them
> > from low-level iovec and csum copying completely. I still haven't finished
> > tracing all possible paths for address to arrive at the points where we
> > currently check that stuff, but so far it looks very doable.
>
> BTW, csum side of that is also chock-full of duplicate access_ok() -
> e.g. generic csum_and_copy_from_user() checks before calling
> csum_partial_copy_from_user(). And generic instance of that is using
> __copy_from_user(), all right, but a _lot_ of non-default instances
> repeat that access_ok().
While we are at it: here's the default csum_and_copy_to_user()
static __inline__ __wsum csum_and_copy_to_user
(const void *src, void __user *dst, int len, __wsum sum, int *err_ptr)
{
sum = csum_partial(src, len, sum);
if (access_ok(VERIFY_WRITE, dst, len)) {
if (copy_to_user(dst, src, len) == 0)
return sum;
}
if (len)
*err_ptr = -EFAULT;
return (__force __wsum)-1; /* invalid checksum */
}
Note that we do that access_ok() and follow it with copy_to_user() on exact
same range, i.e. repeat the same damn check...
next prev parent reply other threads:[~2014-11-07 22:36 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-02 23:05 fs: Use non-const iov in aio_read/aio_write Herbert Xu
2014-11-03 0:16 ` Al Viro
2014-11-03 0:21 ` Al Viro
2014-11-03 0:22 ` Herbert Xu
2014-11-03 0:45 ` Al Viro
2014-11-03 5:37 ` [0/3] net: Kill skb_copy_datagram_const_iovec Herbert Xu
2014-11-03 5:44 ` [PATCH 1/3] tun: Modify const aio_read iovec per do_sock_read Herbert Xu
2014-11-03 5:44 ` [PATCH 3/3] net: Kill skb_copy_datagram_const_iovec Herbert Xu
2014-11-03 5:44 ` [PATCH 2/3] macvtap: Modify const aio_read iovec per do_sock_read Herbert Xu
2014-11-03 20:05 ` [0/3] net: Kill skb_copy_datagram_const_iovec David Miller
2014-11-04 3:38 ` Herbert Xu
2014-11-04 8:31 ` [PATCH 1/4] inet: Add skb_copy_datagram_iter Herbert Xu
2014-11-04 14:32 ` Al Viro
2014-11-04 14:35 ` Al Viro
2014-11-04 14:44 ` Herbert Xu
2014-11-04 14:52 ` Al Viro
2014-11-04 14:55 ` Herbert Xu
2014-11-04 14:42 ` Herbert Xu
2014-11-04 15:13 ` Al Viro
2014-11-05 2:22 ` Herbert Xu
2014-11-05 3:27 ` David Miller
2014-11-05 3:55 ` Al Viro
2014-11-05 4:12 ` Al Viro
2014-11-05 20:51 ` David Miller
2014-11-05 20:50 ` David Miller
2014-11-05 21:07 ` Al Viro
2014-11-05 21:57 ` David Miller
2014-11-06 3:25 ` Al Viro
2014-11-06 5:50 ` ipv4: Use standard iovec primitive in raw_probe_proto_opt Herbert Xu
2014-11-06 6:43 ` Al Viro
2014-11-06 6:46 ` Herbert Xu
2014-11-06 7:11 ` Al Viro
2014-11-06 9:55 ` Jon Maloy
2014-11-06 22:16 ` Al Viro
2014-11-28 5:14 ` Al Viro
2014-11-06 21:28 ` David Miller
2014-11-07 2:00 ` Herbert Xu
2014-11-07 13:25 ` [PATCH 0/2] ipv4: Simplify raw_probe_proto_opt and avoid reading user iov twice Herbert Xu
2014-11-07 13:27 ` [PATCH 1/2] ipv4: Use standard iovec primitive in raw_probe_proto_opt Herbert Xu
2014-11-07 13:27 ` [PATCH 2/2] ipv4: Avoid reading user iov twice after raw_probe_proto_opt Herbert Xu
2014-11-10 19:26 ` [PATCH 0/2] ipv4: Simplify raw_probe_proto_opt and avoid reading user iov twice David Miller
2014-11-06 9:50 ` [PATCH 1/4] inet: Add skb_copy_datagram_iter Jon Maloy
2014-11-07 21:48 ` David Miller
2014-11-07 22:11 ` Al Viro
2014-11-07 22:31 ` Al Viro
2014-11-07 22:35 ` Al Viro [this message]
2014-11-07 23:42 ` Al Viro
2014-11-08 2:21 ` Herbert Xu
2014-11-09 21:19 ` Al Viro
2014-11-10 5:20 ` David Miller
2014-11-10 6:58 ` Al Viro
2014-11-10 7:30 ` David Miller
2014-11-10 9:09 ` Al Viro
2014-11-10 16:18 ` David Miller
2014-11-10 10:14 ` Michael S. Tsirkin
2014-11-07 21:52 ` David Miller
2014-11-05 20:24 ` David Miller
2014-11-06 8:23 ` Herbert Xu
2014-11-06 17:25 ` David Miller
2014-11-07 1:59 ` Herbert Xu
2014-11-07 3:13 ` David Miller
2014-11-07 13:21 ` [PATCH 0/4] Replace skb_copy_datagram_const_iovec with iterator version Herbert Xu
2014-11-07 13:22 ` [PATCH 1/4] inet: Add skb_copy_datagram_iter Herbert Xu
2014-11-07 13:22 ` [PATCH 2/4] tun: Use iovec iterators Herbert Xu
2014-11-07 13:22 ` [PATCH 3/4] macvtap: " Herbert Xu
2014-11-07 13:22 ` [PATCH 4/4] net: Kill skb_copy_datagram_const_iovec Herbert Xu
2014-11-06 8:27 ` [PATCH 0/4] Replace skb_copy_datagram_const_iovec with iterator version Herbert Xu
2014-11-06 8:28 ` [PATCH 1/4] inet: Add skb_copy_datagram_iter Herbert Xu
2014-11-06 17:30 ` Al Viro
2014-11-07 1:58 ` Herbert Xu
2014-11-06 8:28 ` [PATCH 2/4] tun: Use iovec iterators Herbert Xu
2014-11-06 8:28 ` [PATCH 3/4] macvtap: " Herbert Xu
2014-11-06 17:33 ` Al Viro
2014-11-06 8:28 ` [PATCH 4/4] net: Kill skb_copy_datagram_const_iovec Herbert Xu
2014-11-04 8:31 ` [PATCH 2/4] tun: Use iovec iterators Herbert Xu
2014-11-04 8:37 ` Herbert Xu
2014-11-05 2:49 ` YOSHIFUJI Hideaki
2014-11-05 3:41 ` Herbert Xu
2014-11-04 8:31 ` [PATCH 3/4] macvtap: " Herbert Xu
2014-11-04 8:31 ` [PATCH 4/4] net: Kill skb_copy_datagram_const_iovec Herbert Xu
2014-11-04 5:45 ` [0/3] " Al Viro
2014-11-05 1:53 ` Al Viro
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