linux.git/net/sctp/socket.c, branch v4.15

sctp: do not allow the v4 socket to bind a v4mapped v6 address

2018-01-16T19:24:20+00:00

The check in sctp_sockaddr_af is not robust enough to forbid binding a
v4mapped v6 addr on a v4 socket.

The worse thing is that v4 socket's bind_verify would not convert this
v4mapped v6 addr to a v4 addr. syzbot even reported a crash as the v4
socket bound a v6 addr.

This patch is to fix it by doing the common sa.sa_family check first,
then AF_INET check for v4mapped v6 addrs.

Fixes: 7dab83de50c7 ("sctp: Support ipv6only AF_INET6 sockets.")
Reported-by: syzbot+7b7b518b1228d2743963@syzkaller.appspotmail.com
Acked-by: Neil Horman 
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: return error if the asoc has been peeled off in sctp_wait_for_sndbuf

2018-01-16T19:22:51+00:00

After commit cea0cc80a677 ("sctp: use the right sk after waking up from
wait_buf sleep"), it may change to lock another sk if the asoc has been
peeled off in sctp_wait_for_sndbuf.

However, the asoc's new sk could be already closed elsewhere, as it's in
the sendmsg context of the old sk that can't avoid the new sk's closing.
If the sk's last one refcnt is held by this asoc, later on after putting
this asoc, the new sk will be freed, while under it's own lock.

This patch is to revert that commit, but fix the old issue by returning
error under the old sk's lock.

Fixes: cea0cc80a677 ("sctp: use the right sk after waking up from wait_buf sleep")
Reported-by: syzbot+ac6ea7baa4432811eb50@syzkaller.appspotmail.com
Signed-off-by: Xin Long 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

sctp: reinit stream if stream outcnt has been change by sinit in sendmsg

2018-01-16T19:20:21+00:00

After introducing sctp_stream structure, sctp uses stream->outcnt as the
out stream nums instead of c.sinit_num_ostreams.

However when users use sinit in cmsg, it only updates c.sinit_num_ostreams
in sctp_sendmsg. At that moment, stream->outcnt is still using previous
value. If it's value is not updated, the sinit_num_ostreams of sinit could
not really work.

This patch is to fix it by updating stream->outcnt and reiniting stream
if stream outcnt has been change by sinit in sendmsg.

Fixes: a83863174a61 ("sctp: prepare asoc stream for stream reconf")
Signed-off-by: Xin Long 
Acked-by: Neil Horman 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: make use of pre-calculated len

2018-01-10T19:53:22+00:00

Some sockopt handling functions were calculating the length of the
buffer to be written to userspace and then calculating it again when
actually writing the buffer, which could lead to some write not using
an up-to-date length.

This patch updates such places to just make use of the len variable.

Also, replace some sizeof(type) to sizeof(var).

Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: add a ceiling to optlen in some sockopts

2018-01-10T19:53:22+00:00

Hangbin Liu reported that some sockopt calls could cause the kernel to log
a warning on memory allocation failure if the user supplied a large optlen
value. That is because some of them called memdup_user() without a ceiling
on optlen, allowing it to try to allocate really large buffers.

This patch adds a ceiling by limiting optlen to the maximum allowed that
would still make sense for these sockopt.

Reported-by: Hangbin Liu 
Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: GFP_ATOMIC is not needed in sctp_setsockopt_events

2018-01-10T19:53:22+00:00

So replace it with GFP_USER and also add __GFP_NOWARN.

Signed-off-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller

sctp: Replace use of sockets_allocated with specified macro.

2017-12-27T18:47:52+00:00

The patch(180d8cd942ce) replaces all uses of struct sock fields'
memory_pressure, memory_allocated, sockets_allocated, and sysctl_mem
to accessor macros. But the sockets_allocated field of sctp sock is
not replaced at all. Then replace it now for unifying the code.

Fixes: 180d8cd942ce ("foundations of per-cgroup memory pressure controlling.")
Cc: Glauber Costa 
Signed-off-by: Tonghao Zhang 
Signed-off-by: David S. Miller

sctp: make sure stream nums can match optlen in sctp_setsockopt_reset_streams

2017-12-11T19:08:21+00:00

Now in sctp_setsockopt_reset_streams, it only does the check
optlen < sizeof(*params) for optlen. But it's not enough, as
params->srs_number_streams should also match optlen.

If the streams in params->srs_stream_list are less than stream
nums in params->srs_number_streams, later when dereferencing
the stream list, it could cause a slab-out-of-bounds crash, as
reported by syzbot.

This patch is to fix it by also checking the stream numbers in
sctp_setsockopt_reset_streams to make sure at least it's not
greater than the streams in the list.

Fixes: 7f9d68ac944e ("sctp: implement sender-side procedures for SSN Reset Request Parameter")
Reported-by: Dmitry Vyukov 
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller

make sock_alloc_file() do sock_release() on failures

2017-12-05T23:39:29+00:00

This changes calling conventions (and simplifies the hell out
the callers).  New rules: once struct socket had been passed
to sock_alloc_file(), it's been consumed either by struct file
or by sock_release() done by sock_alloc_file().  Either way
the caller should not do sock_release() after that point.

Reviewed-by: Eric Dumazet 
Signed-off-by: Al Viro 
Signed-off-by: David S. Miller

sctp: use right member as the param of list_for_each_entry

2017-11-28T20:55:44+00:00

Commit d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues
when migrating a sock") made a mistake that using 'list' as the param of
list_for_each_entry to traverse the retransmit, sacked and abandoned
queues, while chunks are using 'transmitted_list' to link into these
queues.

It could cause NULL dereference panic if there are chunks in any of these
queues when peeling off one asoc.

So use the chunk member 'transmitted_list' instead in this patch.

Fixes: d04adf1b3551 ("sctp: reset owner sk for data chunks on out queues when migrating a sock")
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller