linux-stable.git/include/net/sctp/structs.h, branch linux-6.17.y

sctp: Replace sockaddr with sockaddr_inet in sctp_addr union

2025-07-25T22:29:58+00:00

As part of the removal of the variably-sized sockaddr for kernel
internals, replace struct sockaddr with sockaddr_inet in the sctp_addr
union.

No binary changes; the union size remains unchanged due to sockaddr_inet
matching the size of sockaddr_in6.

Signed-off-by: Kees Cook 
Link: https://patch.msgid.link/20250722171836.1078436-3-kees@kernel.org
Signed-off-by: Jakub Kicinski

sctp: Remove unused sctp_assoc_del_peer and sctp_chunk_iif

2025-05-05T23:51:12+00:00

sctp_assoc_del_peer() last use was removed in 2015 by
commit 73e6742027f5 ("sctp: Do not try to search for the transport twice")
which now uses rm_peer instead of del_peer.

sctp_chunk_iif() last use was removed in 2016 by
commit 1f45f78f8e51 ("sctp: allow GSO frags to access the chunk too")

Remove them.

Signed-off-by: Dr. David Alan Gilbert 
Acked-by: Xin Long 
Link: https://patch.msgid.link/20250501233815.99832-1-linux@treblig.org
Signed-off-by: Jakub Kicinski

sctp: detect and prevent references to a freed transport in sendmsg

2025-04-08T09:34:06+00:00

sctp_sendmsg() re-uses associations and transports when possible by
doing a lookup based on the socket endpoint and the message destination
address, and then sctp_sendmsg_to_asoc() sets the selected transport in
all the message chunks to be sent.

There's a possible race condition if another thread triggers the removal
of that selected transport, for instance, by explicitly unbinding an
address with setsockopt(SCTP_SOCKOPT_BINDX_REM), after the chunks have
been set up and before the message is sent. This can happen if the send
buffer is full, during the period when the sender thread temporarily
releases the socket lock in sctp_wait_for_sndbuf().

This causes the access to the transport data in
sctp_outq_select_transport(), when the association outqueue is flushed,
to result in a use-after-free read.

This change avoids this scenario by having sctp_transport_free() signal
the freeing of the transport, tagging it as "dead". In order to do this,
the patch restores the "dead" bit in struct sctp_transport, which was
removed in
commit 47faa1e4c50e ("sctp: remove the dead field of sctp_transport").

Then, in the scenario where the sender thread has released the socket
lock in sctp_wait_for_sndbuf(), the bit is checked again after
re-acquiring the socket lock to detect the deletion. This is done while
holding a reference to the transport to prevent it from being freed in
the process.

If the transport was deleted while the socket lock was relinquished,
sctp_sendmsg_to_asoc() will return -EAGAIN to let userspace retry the
send.

The bug was found by a private syzbot instance (see the error report [1]
and the C reproducer that triggers it [2]).

Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport.txt [1]
Link: https://people.igalia.com/rcn/kernel_logs/20250402__KASAN_slab-use-after-free_Read_in_sctp_outq_select_transport__repro.c [2]
Cc: stable@vger.kernel.org
Fixes: df132eff4638 ("sctp: clear the transport of some out_chunk_list chunks in sctp_assoc_rm_peer")
Suggested-by: Xin Long 
Signed-off-by: Ricardo Cañuelo Navarro 
Acked-by: Xin Long 
Link: https://patch.msgid.link/20250404-kasan_slab-use-after-free_read_in_sctp_outq_select_transport__20250404-v1-1-5ce4a0b78ef2@igalia.com
Signed-off-by: Paolo Abeni

sctp: Correct spelling in headers

2024-08-26T16:37:23+00:00

Correct spelling in sctp.h and structs.h.
As reported by codespell.

Cc: Marcelo Ricardo Leitner 
Signed-off-by: Simon Horman 
Acked-by: Xin Long 
Link: https://patch.msgid.link/20240822-net-spell-v1-10-3a98971ce2d2@kernel.org
Signed-off-by: Jakub Kicinski

sctp: preserve const qualifier in sctp_sk()

2024-02-05T11:08:06+00:00

We can change sctp_sk() to propagate its argument const qualifier,
thanks to container_of_const().

Signed-off-by: Eric Dumazet 
Cc: Marcelo Ricardo Leitner 
Cc: Xin Long 
Acked-by: Xin Long 
Signed-off-by: David S. Miller

sctp: Remove unused function declarations

2023-08-03T01:42:03+00:00

These declarations are never implemented since beginning of git history.

Signed-off-by: Yue Haibing 
Reviewed-by: Simon Horman 
Acked-by: Xin Long 
Link: https://lore.kernel.org/r/20230731141030.32772-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski

sctp: delete the nested flexible array peer_init

2023-04-21T07:19:30+00:00

This patch deletes the flexible-array peer_init[] from the structure
sctp_cookie to avoid some sparse warnings:

  # make C=2 CF="-Wflexible-array-nested" M=./net/sctp/
  net/sctp/sm_make_chunk.c: note: in included file (through include/net/sctp/sctp.h):
  ./include/net/sctp/structs.h:1588:28: warning: nested flexible array
  ./include/net/sctp/structs.h:343:28: warning: nested flexible array

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: delete the obsolete code for the host name address param

2023-04-17T07:28:20+00:00

In the latest RFC9260, the Host Name Address param has been deprecated.
For INIT chunk:

  Note 3: An INIT chunk MUST NOT contain the Host Name Address
  parameter.  The receiver of an INIT chunk containing a Host Name
  Address parameter MUST send an ABORT chunk and MAY include an
  "Unresolvable Address" error cause.

For Supported Address Types:

  The value indicating the Host Name Address parameter MUST NOT be
  used when sending this parameter and MUST be ignored when receiving
  this parameter.

Currently Linux SCTP doesn't really support Host Name Address param,
but only saves some flag and print debug info, which actually won't
even be triggered due to the verification in sctp_verify_param().
This patch is to delete those dead code.

Signed-off-by: Xin Long 
Signed-off-by: David S. Miller

sctp: add weighted fair queueing stream scheduler

2023-03-09T10:31:44+00:00

As it says in rfc8260#section-3.6 about the weighted fair queueing
scheduler:

   A Weighted Fair Queueing scheduler between the streams is used.  The
   weight is configurable per outgoing SCTP stream.  This scheduler
   considers the lengths of the messages of each stream and schedules
   them in a specific way to use the capacity according to the given
   weights.  If the weight of stream S1 is n times the weight of stream
   S2, the scheduler should assign to stream S1 n times the capacity it
   assigns to stream S2.  The details are implementation dependent.
   Interleaving user messages allows for a better realization of the
   capacity usage according to the given weights.

This patch adds Weighted Fair Queueing Scheduler actually based on
the code of Fair Capacity Scheduler by adding fc_weight into struct
sctp_stream_out_ext and taking it into account when sorting stream->
fc_list in sctp_sched_fc_sched() and sctp_sched_fc_dequeue_done().

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: Paolo Abeni

sctp: add fair capacity stream scheduler

2023-03-09T10:31:44+00:00

As it says in rfc8260#section-3.5 about the fair capacity scheduler:

   A fair capacity distribution between the streams is used.  This
   scheduler considers the lengths of the messages of each stream and
   schedules them in a specific way to maintain an equal capacity for
   all streams.  The details are implementation dependent.  interleaving
   user messages allows for a better realization of the fair capacity
   usage.

This patch adds Fair Capacity Scheduler based on the foundations added
by commit 5bbbbe32a431 ("sctp: introduce stream scheduler foundations"):

A fc_list and a fc_length are added into struct sctp_stream_out_ext and
a fc_list is added into struct sctp_stream. In .enqueue, when there are
chunks enqueued into a stream, this stream will be linked into stream->
fc_list by its fc_list ordered by its fc_length. In .dequeue, it always
picks up the 1st skb from stream->fc_list. In .dequeue_done, fc_length
is increased by chunk's len and update its location in stream->fc_list
according to the its new fc_length.

Note that when the new fc_length overflows in .dequeue_done, instead of
resetting all fc_lengths to 0, we only reduced them by U32_MAX / 4 to
avoid a moment of imbalance in the scheduling, as Marcelo suggested.

Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: Paolo Abeni