On Wed, Mar 7, 2018 at 9:07 PM, Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
> Hi all,
>
> On Mon, 5 Mar 2018 12:40:54 +1100 Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> wrote:
>>
>> Today's linux-next merge of the selinux tree got a conflict in:
>>
>> net/sctp/socket.c
>>
>> between several refactoring commits from the net-next tree and commit:
>>
>> 2277c7cd75e3 ("sctp: Add LSM hooks")
>>
>> from the selinux tree.
>>
>> I fixed it up (I think - see below) and can carry the fix as
>> necessary. This is now fixed as far as linux-next is concerned, but any
>> non trivial conflicts should be mentioned to your upstream maintainer
>> when your tree is submitted for merging. You may also want to consider
>> cooperating with the maintainer of the conflicting tree to minimise any
>> particularly complex conflicts.
>>
>> --
>> Cheers,
>> Stephen Rothwell
>
> The resolution now looks like below (there were more changes to this
> file in the net-next tree). It will keep changing every time this file
> is touched :-(
Xin Long, does this still look okay to you?
> diff --cc net/sctp/socket.c
> index 7d3476a4860d,73b34a6b5b09..000000000000
> --- a/net/sctp/socket.c
> +++ b/net/sctp/socket.c
> @@@ -1606,200 -1622,308 +1622,216 @@@ static int sctp_error(struct sock *sk,
> static int sctp_msghdr_parse(const struct msghdr *msg,
> struct sctp_cmsgs *cmsgs);
>
> -static int sctp_sendmsg(struct sock *sk, struct msghdr *msg, size_t msg_len)
> +static int sctp_sendmsg_parse(struct sock *sk, struct sctp_cmsgs *cmsgs,
> + struct sctp_sndrcvinfo *srinfo,
> + const struct msghdr *msg, size_t msg_len)
> {
> - struct net *net = sock_net(sk);
> - struct sctp_sock *sp;
> - struct sctp_endpoint *ep;
> - struct sctp_association *new_asoc = NULL, *asoc = NULL;
> - struct sctp_transport *transport, *chunk_tp;
> - struct sctp_chunk *chunk;
> - union sctp_addr to;
> - struct sctp_af *af;
> - struct sockaddr *msg_name = NULL;
> - struct sctp_sndrcvinfo default_sinfo;
> - struct sctp_sndrcvinfo *sinfo;
> - struct sctp_initmsg *sinit;
> - sctp_assoc_t associd = 0;
> - struct sctp_cmsgs cmsgs = { NULL };
> - enum sctp_scope scope;
> - bool fill_sinfo_ttl = false, wait_connect = false;
> - struct sctp_datamsg *datamsg;
> - int msg_flags = msg->msg_flags;
> - __u16 sinfo_flags = 0;
> - long timeo;
> + __u16 sflags;
> int err;
>
> - err = 0;
> - sp = sctp_sk(sk);
> - ep = sp->ep;
> + if (sctp_sstate(sk, LISTENING) && sctp_style(sk, TCP))
> + return -EPIPE;
>
> - pr_debug("%s: sk:%p, msg:%p, msg_len:%zu ep:%p\n", __func__, sk,
> - msg, msg_len, ep);
> -
> - /* We cannot send a message over a TCP-style listening socket. */
> - if (sctp_style(sk, TCP) && sctp_sstate(sk, LISTENING)) {
> - err = -EPIPE;
> - goto out_nounlock;
> - }
> + if (msg_len > sk->sk_sndbuf)
> + return -EMSGSIZE;
>
> - /* Parse out the SCTP CMSGs. */
> - err = sctp_msghdr_parse(msg, &cmsgs);
> + memset(cmsgs, 0, sizeof(*cmsgs));
> + err = sctp_msghdr_parse(msg, cmsgs);
> if (err) {
> pr_debug("%s: msghdr parse err:%x\n", __func__, err);
> - goto out_nounlock;
> + return err;
> }
>
> - /* Fetch the destination address for this packet. This
> - * address only selects the association--it is not necessarily
> - * the address we will send to.
> - * For a peeled-off socket, msg_name is ignored.
> - */
> - if (!sctp_style(sk, UDP_HIGH_BANDWIDTH) && msg->msg_name) {
> - int msg_namelen = msg->msg_namelen;
> + memset(srinfo, 0, sizeof(*srinfo));
> + if (cmsgs->srinfo) {
> + srinfo->sinfo_stream = cmsgs->srinfo->sinfo_stream;
> + srinfo->sinfo_flags = cmsgs->srinfo->sinfo_flags;
> + srinfo->sinfo_ppid = cmsgs->srinfo->sinfo_ppid;
> + srinfo->sinfo_context = cmsgs->srinfo->sinfo_context;
> + srinfo->sinfo_assoc_id = cmsgs->srinfo->sinfo_assoc_id;
> + srinfo->sinfo_timetolive = cmsgs->srinfo->sinfo_timetolive;
> + }
>
> - err = sctp_verify_addr(sk, (union sctp_addr *)msg->msg_name,
> - msg_namelen);
> - if (err)
> - return err;
> + if (cmsgs->sinfo) {
> + srinfo->sinfo_stream = cmsgs->sinfo->snd_sid;
> + srinfo->sinfo_flags = cmsgs->sinfo->snd_flags;
> + srinfo->sinfo_ppid = cmsgs->sinfo->snd_ppid;
> + srinfo->sinfo_context = cmsgs->sinfo->snd_context;
> + srinfo->sinfo_assoc_id = cmsgs->sinfo->snd_assoc_id;
> + }
>
> - if (msg_namelen > sizeof(to))
> - msg_namelen = sizeof(to);
> - memcpy(&to, msg->msg_name, msg_namelen);
> - msg_name = msg->msg_name;
> + if (cmsgs->prinfo) {
> + srinfo->sinfo_timetolive = cmsgs->prinfo->pr_value;
> + SCTP_PR_SET_POLICY(srinfo->sinfo_flags,
> + cmsgs->prinfo->pr_policy);
> }
>
> - sinit = cmsgs.init;
> - if (cmsgs.sinfo != NULL) {
> - memset(&default_sinfo, 0, sizeof(default_sinfo));
> - default_sinfo.sinfo_stream = cmsgs.sinfo->snd_sid;
> - default_sinfo.sinfo_flags = cmsgs.sinfo->snd_flags;
> - default_sinfo.sinfo_ppid = cmsgs.sinfo->snd_ppid;
> - default_sinfo.sinfo_context = cmsgs.sinfo->snd_context;
> - default_sinfo.sinfo_assoc_id = cmsgs.sinfo->snd_assoc_id;
> + sflags = srinfo->sinfo_flags;
> + if (!sflags && msg_len)
> + return 0;
>
> - sinfo = &default_sinfo;
> - fill_sinfo_ttl = true;
> - } else {
> - sinfo = cmsgs.srinfo;
> - }
> - /* Did the user specify SNDINFO/SNDRCVINFO? */
> - if (sinfo) {
> - sinfo_flags = sinfo->sinfo_flags;
> - associd = sinfo->sinfo_assoc_id;
> - }
> + if (sctp_style(sk, TCP) && (sflags & (SCTP_EOF | SCTP_ABORT)))
> + return -EINVAL;
>
> - pr_debug("%s: msg_len:%zu, sinfo_flags:0x%x\n", __func__,
> - msg_len, sinfo_flags);
> + if (((sflags & SCTP_EOF) && msg_len > 0) ||
> + (!(sflags & (SCTP_EOF | SCTP_ABORT)) && msg_len == 0))
> + return -EINVAL;
>
> - /* SCTP_EOF or SCTP_ABORT cannot be set on a TCP-style socket. */
> - if (sctp_style(sk, TCP) && (sinfo_flags & (SCTP_EOF | SCTP_ABORT))) {
> - err = -EINVAL;
> - goto out_nounlock;
> - }
> + if ((sflags & SCTP_ADDR_OVER) && !msg->msg_name)
> + return -EINVAL;
>
> - /* If SCTP_EOF is set, no data can be sent. Disallow sending zero
> - * length messages when SCTP_EOF|SCTP_ABORT is not set.
> - * If SCTP_ABORT is set, the message length could be non zero with
> - * the msg_iov set to the user abort reason.
> - */
> - if (((sinfo_flags & SCTP_EOF) && (msg_len > 0)) ||
> - (!(sinfo_flags & (SCTP_EOF|SCTP_ABORT)) && (msg_len == 0))) {
> - err = -EINVAL;
> - goto out_nounlock;
> - }
> + return 0;
> +}
>
> - /* If SCTP_ADDR_OVER is set, there must be an address
> - * specified in msg_name.
> - */
> - if ((sinfo_flags & SCTP_ADDR_OVER) && (!msg->msg_name)) {
> - err = -EINVAL;
> - goto out_nounlock;
> - }
> +static int sctp_sendmsg_new_asoc(struct sock *sk, __u16 sflags,
> + struct sctp_cmsgs *cmsgs,
> + union sctp_addr *daddr,
> + struct sctp_transport **tp)
> +{
> + struct sctp_endpoint *ep = sctp_sk(sk)->ep;
> + struct net *net = sock_net(sk);
> + struct sctp_association *asoc;
> + enum sctp_scope scope;
> + struct cmsghdr *cmsg;
> ++ struct sctp_af *af;
> + int err = -EINVAL;
>
> - transport = NULL;
> + *tp = NULL;
>
> - pr_debug("%s: about to look up association\n", __func__);
> + if (sflags & (SCTP_EOF | SCTP_ABORT))
> + return -EINVAL;
>
> - lock_sock(sk);
> + if (sctp_style(sk, TCP) && (sctp_sstate(sk, ESTABLISHED) ||
> + sctp_sstate(sk, CLOSING)))
> + return -EADDRNOTAVAIL;
>
> - /* If a msg_name has been specified, assume this is to be used. */
> - if (msg_name) {
> - /* Look for a matching association on the endpoint. */
> - asoc = sctp_endpoint_lookup_assoc(ep, &to, &transport);
> + if (sctp_endpoint_is_peeled_off(ep, daddr))
> + return -EADDRNOTAVAIL;
>
> - /* If we could not find a matching association on the
> - * endpoint, make sure that it is not a TCP-style
> - * socket that already has an association or there is
> - * no peeled-off association on another socket.
> - */
> - if (!asoc &&
> - ((sctp_style(sk, TCP) &&
> - (sctp_sstate(sk, ESTABLISHED) ||
> - sctp_sstate(sk, CLOSING))) ||
> - sctp_endpoint_is_peeled_off(ep, &to))) {
> - err = -EADDRNOTAVAIL;
> - goto out_unlock;
> - }
> + if (!ep->base.bind_addr.port) {
> + if (sctp_autobind(sk))
> + return -EAGAIN;
> } else {
> - asoc = sctp_id2assoc(sk, associd);
> - if (!asoc) {
> - err = -EPIPE;
> - goto out_unlock;
> - }
> + if (ep->base.bind_addr.port < inet_prot_sock(net) &&
> + !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE))
> + return -EACCES;
> }
>
> - if (asoc) {
> - pr_debug("%s: just looked up association:%p\n", __func__, asoc);
> + scope = sctp_scope(daddr);
>
> - /* We cannot send a message on a TCP-style SCTP_SS_ESTABLISHED
> - * socket that has an association in CLOSED state. This can
> - * happen when an accepted socket has an association that is
> - * already CLOSED.
> - */
> - if (sctp_state(asoc, CLOSED) && sctp_style(sk, TCP)) {
> - err = -EPIPE;
> - goto out_unlock;
> - }
> ++ /* Label connection socket for first association 1-to-many
> ++ * style for client sequence socket()->sendmsg(). This
> ++ * needs to be done before sctp_assoc_add_peer() as that will
> ++ * set up the initial packet that needs to account for any
> ++ * security ip options (CIPSO/CALIPSO) added to the packet.
> ++ */
> ++ af = sctp_get_af_specific(daddr->sa.sa_family);
> ++ if (!af)
> ++ return -EINVAL;
> ++ err = security_sctp_bind_connect(sk, SCTP_SENDMSG_CONNECT,
> ++ (struct sockaddr *)daddr,
> ++ af->sockaddr_len);
> ++ if (err < 0)
> ++ return err;
> +
> - if (sinfo_flags & SCTP_EOF) {
> - pr_debug("%s: shutting down association:%p\n",
> - __func__, asoc);
> + asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
> + if (!asoc)
> + return -ENOMEM;
>
> - sctp_primitive_SHUTDOWN(net, asoc, NULL);
> - err = 0;
> - goto out_unlock;
> - }
> - if (sinfo_flags & SCTP_ABORT) {
> + if (sctp_assoc_set_bind_addr_from_ep(asoc, scope, GFP_KERNEL) < 0) {
> + err = -ENOMEM;
> + goto free;
> + }
>
> - chunk = sctp_make_abort_user(asoc, msg, msg_len);
> - if (!chunk) {
> - err = -ENOMEM;
> - goto out_unlock;
> - }
> + if (cmsgs->init) {
> + struct sctp_initmsg *init = cmsgs->init;
>
> - pr_debug("%s: aborting association:%p\n",
> - __func__, asoc);
> + if (init->sinit_num_ostreams) {
> + __u16 outcnt = init->sinit_num_ostreams;
>
> - sctp_primitive_ABORT(net, asoc, chunk);
> - err = 0;
> - goto out_unlock;
> + asoc->c.sinit_num_ostreams = outcnt;
> + /* outcnt has been changed, need to re-init stream */
> + err = sctp_stream_init(&asoc->stream, outcnt, 0,
> + GFP_KERNEL);
> + if (err)
> + goto free;
> }
> +
> + if (init->sinit_max_instreams)
> + asoc->c.sinit_max_instreams = init->sinit_max_instreams;
> +
> + if (init->sinit_max_attempts)
> + asoc->max_init_attempts = init->sinit_max_attempts;
> +
> + if (init->sinit_max_init_timeo)
> + asoc->max_init_timeo =
> + msecs_to_jiffies(init->sinit_max_init_timeo);
> }
>
> - /* Do we need to create the association? */
> - if (!asoc) {
> - pr_debug("%s: there is no association yet\n", __func__);
> + *tp = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL, SCTP_UNKNOWN);
> + if (!*tp) {
> + err = -ENOMEM;
> + goto free;
> + }
>
> - if (sinfo_flags & (SCTP_EOF | SCTP_ABORT)) {
> - err = -EINVAL;
> - goto out_unlock;
> - }
> + if (!cmsgs->addrs_msg)
> + return 0;
>
> - /* Check for invalid stream against the stream counts,
> - * either the default or the user specified stream counts.
> - */
> - if (sinfo) {
> - if (!sinit || !sinit->sinit_num_ostreams) {
> - /* Check against the defaults. */
> - if (sinfo->sinfo_stream >=
> - sp->initmsg.sinit_num_ostreams) {
> - err = -EINVAL;
> - goto out_unlock;
> - }
> - } else {
> - /* Check against the requested. */
> - if (sinfo->sinfo_stream >=
> - sinit->sinit_num_ostreams) {
> - err = -EINVAL;
> - goto out_unlock;
> - }
> - }
> - }
> + /* sendv addr list parse */
> + for_each_cmsghdr(cmsg, cmsgs->addrs_msg) {
> + struct sctp_transport *transport;
> + struct sctp_association *old;
> + union sctp_addr _daddr;
> + int dlen;
>
> - /*
> - * API 3.1.2 bind() - UDP Style Syntax
> - * If a bind() or sctp_bindx() is not called prior to a
> - * sendmsg() call that initiates a new association, the
> - * system picks an ephemeral port and will choose an address
> - * set equivalent to binding with a wildcard address.
> - */
> - if (!ep->base.bind_addr.port) {
> - if (sctp_autobind(sk)) {
> - err = -EAGAIN;
> - goto out_unlock;
> - }
> - } else {
> - /*
> - * If an unprivileged user inherits a one-to-many
> - * style socket with open associations on a privileged
> - * port, it MAY be permitted to accept new associations,
> - * but it SHOULD NOT be permitted to open new
> - * associations.
> - */
> - if (ep->base.bind_addr.port < inet_prot_sock(net) &&
> - !ns_capable(net->user_ns, CAP_NET_BIND_SERVICE)) {
> - err = -EACCES;
> - goto out_unlock;
> - }
> - }
> + if (cmsg->cmsg_level != IPPROTO_SCTP ||
> + (cmsg->cmsg_type != SCTP_DSTADDRV4 &&
> + cmsg->cmsg_type != SCTP_DSTADDRV6))
> + continue;
>
> - scope = sctp_scope(&to);
> + daddr = &_daddr;
> + memset(daddr, 0, sizeof(*daddr));
> + dlen = cmsg->cmsg_len - sizeof(struct cmsghdr);
> + if (cmsg->cmsg_type == SCTP_DSTADDRV4) {
> + if (dlen < sizeof(struct in_addr))
> + goto free;
> +
> + dlen = sizeof(struct in_addr);
> + daddr->v4.sin_family = AF_INET;
> + daddr->v4.sin_port = htons(asoc->peer.port);
> + memcpy(&daddr->v4.sin_addr, CMSG_DATA(cmsg), dlen);
> + } else {
> + if (dlen < sizeof(struct in6_addr))
> + goto free;
>
> - /* Label connection socket for first association 1-to-many
> - * style for client sequence socket()->sendmsg(). This
> - * needs to be done before sctp_assoc_add_peer() as that will
> - * set up the initial packet that needs to account for any
> - * security ip options (CIPSO/CALIPSO) added to the packet.
> - */
> - af = sctp_get_af_specific(to.sa.sa_family);
> - if (!af) {
> - err = -EINVAL;
> - goto out_unlock;
> + dlen = sizeof(struct in6_addr);
> + daddr->v6.sin6_family = AF_INET6;
> + daddr->v6.sin6_port = htons(asoc->peer.port);
> + memcpy(&daddr->v6.sin6_addr, CMSG_DATA(cmsg), dlen);
> }
> - err = security_sctp_bind_connect(sk, SCTP_SENDMSG_CONNECT,
> - (struct sockaddr *)&to,
> - af->sockaddr_len);
> - if (err < 0)
> - goto out_unlock;
> + err = sctp_verify_addr(sk, daddr, sizeof(*daddr));
> + if (err)
> + goto free;
>
> - new_asoc = sctp_association_new(ep, sk, scope, GFP_KERNEL);
> - if (!new_asoc) {
> - err = -ENOMEM;
> - goto out_unlock;
> - }
> - asoc = new_asoc;
> - err = sctp_assoc_set_bind_addr_from_ep(asoc, scope, GFP_KERNEL);
> - if (err < 0) {
> - err = -ENOMEM;
> - goto out_free;
> + old = sctp_endpoint_lookup_assoc(ep, daddr, &transport);
> + if (old && old != asoc) {
> + if (old->state >= SCTP_STATE_ESTABLISHED)
> + err = -EISCONN;
> + else
> + err = -EALREADY;
> + goto free;
> }
>
> - /* If the SCTP_INIT ancillary data is specified, set all
> - * the association init values accordingly.
> - */
> - if (sinit) {
> - if (sinit->sinit_num_ostreams) {
> - __u16 outcnt = sinit->sinit_num_ostreams;
> -
> - asoc->c.sinit_num_ostreams = outcnt;
> - /* outcnt has been changed, so re-init stream */
> - err = sctp_stream_init(&asoc->stream, outcnt, 0,
> - GFP_KERNEL);
> - if (err)
> - goto out_free;
> - }
> - if (sinit->sinit_max_instreams) {
> - asoc->c.sinit_max_instreams =
> - sinit->sinit_max_instreams;
> - }
> - if (sinit->sinit_max_attempts) {
> - asoc->max_init_attempts
> - = sinit->sinit_max_attempts;
> - }
> - if (sinit->sinit_max_init_timeo) {
> - asoc->max_init_timeo =
> - msecs_to_jiffies(sinit->sinit_max_init_timeo);
> - }
> + if (sctp_endpoint_is_peeled_off(ep, daddr)) {
> + err = -EADDRNOTAVAIL;
> + goto free;
> }
>
> - /* Prime the peer's transport structures. */
> - transport = sctp_assoc_add_peer(asoc, &to, GFP_KERNEL, SCTP_UNKNOWN);
> + transport = sctp_assoc_add_peer(asoc, daddr, GFP_KERNEL,
> + SCTP_UNKNOWN);
> if (!transport) {
> err = -ENOMEM;
> - goto out_free;
> + goto free;
> }
> }
>
--
paul moore
www.paul-moore.com
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