Re: linux-next: manual merge of the selinux tree with the net-next tree

From: Stephen Rothwell
Date: Wed Mar 07 2018 - 21:07:35 EST


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 :-(

--
Cheers,
Stephen Rothwell

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;
}
}

Attachment: pgpRRWEg6Mr02.pgp
Description: OpenPGP digital signature