Linux-WPAN Archive on lore.kernel.org
 help / color / Atom feed
From: Ido Schimmel <idosch@idosch.org>
To: Christoph Hellwig <hch@lst.de>
Cc: "David S. Miller" <davem@davemloft.net>,
	Jakub Kicinski <kuba@kernel.org>,
	Alexei Starovoitov <ast@kernel.org>,
	Daniel Borkmann <daniel@iogearbox.net>,
	Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
	Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
	Eric Dumazet <edumazet@google.com>,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	netdev@vger.kernel.org, bpf@vger.kernel.org,
	netfilter-devel@vger.kernel.org, coreteam@netfilter.org,
	linux-sctp@vger.kernel.org, linux-hams@vger.kernel.org,
	linux-bluetooth@vger.kernel.org,
	bridge@lists.linux-foundation.org, linux-can@vger.kernel.org,
	dccp@vger.kernel.org, linux-decnet-user@lists.sourceforge.net,
	linux-wpan@vger.kernel.org, linux-s390@vger.kernel.org,
	mptcp@lists.01.org, lvs-devel@vger.kernel.org,
	rds-devel@oss.oracle.com, linux-afs@lists.infradead.org,
	tipc-discussion@lists.sourceforge.net, linux-x25@vger.kernel.org
Subject: Re: [PATCH 19/26] net/ipv6: switch ipv6_flowlabel_opt to sockptr_t
Date: Mon, 27 Jul 2020 15:15:05 +0300
Message-ID: <20200727121505.GA1804864@shredder> (raw)
In-Reply-To: <20200723060908.50081-20-hch@lst.de>

On Thu, Jul 23, 2020 at 08:09:01AM +0200, Christoph Hellwig wrote:
> Pass a sockptr_t to prepare for set_fs-less handling of the kernel
> pointer from bpf-cgroup.
> 
> Note that the get case is pretty weird in that it actually copies data
> back to userspace from setsockopt.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  include/net/ipv6.h       |  2 +-
>  net/ipv6/ip6_flowlabel.c | 16 +++++++++-------
>  net/ipv6/ipv6_sockglue.c |  2 +-
>  3 files changed, 11 insertions(+), 9 deletions(-)
> 
> diff --git a/include/net/ipv6.h b/include/net/ipv6.h
> index 262fc88dbd7e2f..4c9d89b5d73268 100644
> --- a/include/net/ipv6.h
> +++ b/include/net/ipv6.h
> @@ -406,7 +406,7 @@ struct ipv6_txoptions *fl6_merge_options(struct ipv6_txoptions *opt_space,
>  					 struct ip6_flowlabel *fl,
>  					 struct ipv6_txoptions *fopt);
>  void fl6_free_socklist(struct sock *sk);
> -int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen);
> +int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen);
>  int ipv6_flowlabel_opt_get(struct sock *sk, struct in6_flowlabel_req *freq,
>  			   int flags);
>  int ip6_flowlabel_init(void);
> diff --git a/net/ipv6/ip6_flowlabel.c b/net/ipv6/ip6_flowlabel.c
> index 27ee6de9beffc4..6b3c315f3d461a 100644
> --- a/net/ipv6/ip6_flowlabel.c
> +++ b/net/ipv6/ip6_flowlabel.c
> @@ -371,7 +371,7 @@ static int fl6_renew(struct ip6_flowlabel *fl, unsigned long linger, unsigned lo
>  
>  static struct ip6_flowlabel *
>  fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
> -	  char __user *optval, int optlen, int *err_p)
> +	  sockptr_t optval, int optlen, int *err_p)
>  {
>  	struct ip6_flowlabel *fl = NULL;
>  	int olen;
> @@ -401,7 +401,8 @@ fl_create(struct net *net, struct sock *sk, struct in6_flowlabel_req *freq,
>  		memset(fl->opt, 0, sizeof(*fl->opt));
>  		fl->opt->tot_len = sizeof(*fl->opt) + olen;
>  		err = -EFAULT;
> -		if (copy_from_user(fl->opt+1, optval+CMSG_ALIGN(sizeof(*freq)), olen))
> +		sockptr_advance(optval, CMSG_ALIGN(sizeof(*freq)));
> +		if (copy_from_sockptr(fl->opt + 1, optval, olen))
>  			goto done;
>  
>  		msg.msg_controllen = olen;
> @@ -604,7 +605,7 @@ static int ipv6_flowlabel_renew(struct sock *sk, struct in6_flowlabel_req *freq)
>  }
>  
>  static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
> -		void __user *optval, int optlen)
> +		sockptr_t optval, int optlen)
>  {
>  	struct ipv6_fl_socklist *sfl, *sfl1 = NULL;
>  	struct ip6_flowlabel *fl, *fl1 = NULL;
> @@ -702,8 +703,9 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
>  		goto recheck;
>  
>  	if (!freq->flr_label) {
> -		if (copy_to_user(&((struct in6_flowlabel_req __user *) optval)->flr_label,
> -				 &fl->label, sizeof(fl->label))) {
> +		sockptr_advance(optval,
> +				offsetof(struct in6_flowlabel_req, flr_label));

Christoph,

I see a regression with IPv6 flowlabel that I bisected to this patch.
When passing '-F 0' to 'ping' the flow label should be random, yet it's
the same every time after this patch.

It seems that the pointer is never advanced after the call to
sockptr_advance() because it is passed by value and not by reference.
Even if you were to pass it by reference I think you would later need to
call sockptr_decrease() or something similar. Otherwise it is very
error-prone.

Maybe adding an offset to copy_to_sockptr() and copy_from_sockptr() is
better?

Thanks

> +		if (copy_to_sockptr(optval, &fl->label, sizeof(fl->label))) {
>  			/* Intentionally ignore fault. */
>  		}
>  	}
> @@ -716,13 +718,13 @@ static int ipv6_flowlabel_get(struct sock *sk, struct in6_flowlabel_req *freq,
>  	return err;
>  }
>  
> -int ipv6_flowlabel_opt(struct sock *sk, char __user *optval, int optlen)
> +int ipv6_flowlabel_opt(struct sock *sk, sockptr_t optval, int optlen)
>  {
>  	struct in6_flowlabel_req freq;
>  
>  	if (optlen < sizeof(freq))
>  		return -EINVAL;
> -	if (copy_from_user(&freq, optval, sizeof(freq)))
> +	if (copy_from_sockptr(&freq, optval, sizeof(freq)))
>  		return -EFAULT;
>  
>  	switch (freq.flr_action) {
> diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
> index 119dfaf5f4bb26..3897fb55372d38 100644
> --- a/net/ipv6/ipv6_sockglue.c
> +++ b/net/ipv6/ipv6_sockglue.c
> @@ -929,7 +929,7 @@ static int do_ipv6_setsockopt(struct sock *sk, int level, int optname,
>  		retv = 0;
>  		break;
>  	case IPV6_FLOWLABEL_MGR:
> -		retv = ipv6_flowlabel_opt(sk, optval, optlen);
> +		retv = ipv6_flowlabel_opt(sk, USER_SOCKPTR(optval), optlen);
>  		break;
>  	case IPV6_IPSEC_POLICY:
>  	case IPV6_XFRM_POLICY:
> -- 
> 2.27.0
> 

  reply index

Thread overview: 64+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-23  6:08 get rid of the address_space override in setsockopt v2 Christoph Hellwig
2020-07-23  6:08 ` [PATCH 01/26] bpfilter: fix up a sparse annotation Christoph Hellwig
2020-07-23 11:14   ` Luc Van Oostenryck
2020-07-23  6:08 ` [PATCH 02/26] net/bpfilter: split __bpfilter_process_sockopt Christoph Hellwig
2020-07-23  6:08 ` [PATCH 03/26] bpfilter: reject kernel addresses Christoph Hellwig
2020-07-23 14:42   ` David Laight
2020-07-23 14:44     ` 'Christoph Hellwig'
2020-07-23 14:56       ` David Laight
2020-07-23  6:08 ` [PATCH 04/26] net: add a new sockptr_t type Christoph Hellwig
2020-07-23 15:40   ` Jan Engelhardt
2020-07-23 16:40   ` Eric Dumazet
2020-07-23 16:44     ` Christoph Hellwig
2020-07-23  6:08 ` [PATCH 05/26] net: switch copy_bpf_fprog_from_user to sockptr_t Christoph Hellwig
2020-07-23  6:08 ` [PATCH 06/26] net: switch sock_setbindtodevice " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 07/26] net: switch sock_set_timeout " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 08/26] " Christoph Hellwig
2020-07-23  8:39   ` [MPTCP] " Matthieu Baerts
2020-07-23  6:08 ` [PATCH 09/26] net/xfrm: switch xfrm_user_policy " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 10/26] netfilter: remove the unused user argument to do_update_counters Christoph Hellwig
2020-07-23  6:08 ` [PATCH 11/26] netfilter: switch xt_copy_counters to sockptr_t Christoph Hellwig
2020-07-23  6:08 ` [PATCH 12/26] netfilter: switch nf_setsockopt " Christoph Hellwig
2020-07-27 15:03   ` Jason A. Donenfeld
2020-07-27 15:06     ` Christoph Hellwig
2020-07-27 16:16       ` Jason A. Donenfeld
2020-07-27 16:23         ` Christoph Hellwig
2020-07-28  8:07           ` David Laight
2020-07-28  8:17             ` Jason A. Donenfeld
2020-07-27 16:16     ` Christoph Hellwig
2020-07-27 16:21       ` Jason A. Donenfeld
2020-07-23  6:08 ` [PATCH 13/26] bpfilter: switch bpfilter_ip_set_sockopt " Christoph Hellwig
2020-07-23 11:16   ` David Laight
2020-07-23 11:44     ` 'Christoph Hellwig'
2020-07-23  6:08 ` [PATCH 14/26] net/ipv4: switch ip_mroute_setsockopt " Christoph Hellwig
2020-07-23  6:08 ` [PATCH 15/26] net/ipv4: merge ip_options_get and ip_options_get_from_user Christoph Hellwig
2020-07-23  6:08 ` [PATCH 16/26] net/ipv4: switch do_ip_setsockopt to sockptr_t Christoph Hellwig
2020-07-23  6:08 ` [PATCH 17/26] net/ipv6: switch ip6_mroute_setsockopt " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 18/26] net/ipv6: split up ipv6_flowlabel_opt Christoph Hellwig
2020-07-23  6:09 ` [PATCH 19/26] net/ipv6: switch ipv6_flowlabel_opt to sockptr_t Christoph Hellwig
2020-07-27 12:15   ` Ido Schimmel [this message]
2020-07-27 13:00     ` Christoph Hellwig
2020-07-27 13:33       ` Ido Schimmel
2020-07-27 16:15         ` Christoph Hellwig
2020-07-27 18:22           ` Ido Schimmel
2020-07-27 13:24     ` David Laight
2020-07-23  6:09 ` [PATCH 20/26] net/ipv6: factor out a ipv6_set_opt_hdr helper Christoph Hellwig
2020-07-23  6:09 ` [PATCH 21/26] net/ipv6: switch do_ipv6_setsockopt to sockptr_t Christoph Hellwig
2020-07-23  6:09 ` [PATCH 22/26] net/udp: switch udp_lib_setsockopt " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 23/26] net/tcp: switch ->md5_parse " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 24/26] net/tcp: switch do_tcp_setsockopt " Christoph Hellwig
2020-07-23  6:09 ` [PATCH 25/26] net: pass a sockptr_t into ->setsockopt Christoph Hellwig
2020-07-23  8:39   ` [MPTCP] " Matthieu Baerts
2020-08-06 22:21   ` Eric Dumazet
2020-08-07  7:21     ` Christoph Hellwig
2020-08-07  9:18     ` David Laight
2020-08-07 18:29       ` Eric Dumazet
2020-08-08 13:54         ` David Laight
2020-07-23  6:09 ` [PATCH 26/26] net: optimize the sockptr_t for unified kernel/user address spaces Christoph Hellwig
2020-07-24 22:43 ` get rid of the address_space override in setsockopt v2 David Miller
2020-07-26  7:03   ` Christoph Hellwig
2020-07-26  7:08     ` Andreas Schwab
2020-07-26  7:46     ` David Miller
2020-07-27  9:51   ` David Laight
2020-07-27 13:48     ` Al Viro
2020-07-27 14:09       ` David Laight

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20200727121505.GA1804864@shredder \
    --to=idosch@idosch.org \
    --cc=ast@kernel.org \
    --cc=bpf@vger.kernel.org \
    --cc=bridge@lists.linux-foundation.org \
    --cc=coreteam@netfilter.org \
    --cc=daniel@iogearbox.net \
    --cc=davem@davemloft.net \
    --cc=dccp@vger.kernel.org \
    --cc=edumazet@google.com \
    --cc=hch@lst.de \
    --cc=kuba@kernel.org \
    --cc=kuznet@ms2.inr.ac.ru \
    --cc=linux-afs@lists.infradead.org \
    --cc=linux-bluetooth@vger.kernel.org \
    --cc=linux-can@vger.kernel.org \
    --cc=linux-crypto@vger.kernel.org \
    --cc=linux-decnet-user@lists.sourceforge.net \
    --cc=linux-hams@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux-sctp@vger.kernel.org \
    --cc=linux-wpan@vger.kernel.org \
    --cc=linux-x25@vger.kernel.org \
    --cc=lvs-devel@vger.kernel.org \
    --cc=mptcp@lists.01.org \
    --cc=netdev@vger.kernel.org \
    --cc=netfilter-devel@vger.kernel.org \
    --cc=rds-devel@oss.oracle.com \
    --cc=tipc-discussion@lists.sourceforge.net \
    --cc=yoshfuji@linux-ipv6.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-WPAN Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-wpan/0 linux-wpan/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-wpan linux-wpan/ https://lore.kernel.org/linux-wpan \
		linux-wpan@vger.kernel.org
	public-inbox-index linux-wpan

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-wpan


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git