Commit graph

1991 commits

Author SHA1 Message Date
David S. Miller
13209a8f73 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The MSCC bug fix in 'net' had to be slightly adjusted because the
register accesses are done slightly differently in net-next.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-24 13:47:27 -07:00
Jere Leppänen
d3e8e4c118 sctp: Start shutdown on association restart if in SHUTDOWN-SENT state and socket is closed
Commit bdf6fa52f0 ("sctp: handle association restarts when the
socket is closed.") starts shutdown when an association is restarted,
if in SHUTDOWN-PENDING state and the socket is closed. However, the
rationale stated in that commit applies also when in SHUTDOWN-SENT
state - we don't want to move an association to ESTABLISHED state when
the socket has been closed, because that results in an association
that is unreachable from user space.

The problem scenario:

1.  Client crashes and/or restarts.

2.  Server (using one-to-one socket) calls close(). SHUTDOWN is lost.

3.  Client reconnects using the same addresses and ports.

4.  Server's association is restarted. The association and the socket
    move to ESTABLISHED state, even though the server process has
    closed its descriptor.

Also, after step 4 when the server process exits, some resources are
leaked in an attempt to release the underlying inet sock structure in
ESTABLISHED state:

    IPv4: Attempt to release TCP socket in state 1 00000000377288c7

Fix by acting the same way as in SHUTDOWN-PENDING state. That is, if
an association is restarted in SHUTDOWN-SENT state and the socket is
closed, then start shutdown and don't move the association or the
socket to ESTABLISHED state.

Fixes: bdf6fa52f0 ("sctp: handle association restarts when the socket is closed.")
Signed-off-by: Jere Leppänen <jere.leppanen@nokia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-22 15:47:59 -07:00
Neil Horman
20a785aa52 sctp: Don't add the shutdown timer if its already been added
This BUG halt was reported a while back, but the patch somehow got
missed:

PID: 2879   TASK: c16adaa0  CPU: 1   COMMAND: "sctpn"
 #0 [f418dd28] crash_kexec at c04a7d8c
 #1 [f418dd7c] oops_end at c0863e02
 #2 [f418dd90] do_invalid_op at c040aaca
 #3 [f418de28] error_code (via invalid_op) at c08631a5
    EAX: f34baac0  EBX: 00000090  ECX: f418deb0  EDX: f5542950  EBP: 00000000
    DS:  007b      ESI: f34ba800  ES:  007b      EDI: f418dea0  GS:  00e0
    CS:  0060      EIP: c046fa5e  ERR: ffffffff  EFLAGS: 00010286
 #4 [f418de5c] add_timer at c046fa5e
 #5 [f418de68] sctp_do_sm at f8db8c77 [sctp]
 #6 [f418df30] sctp_primitive_SHUTDOWN at f8dcc1b5 [sctp]
 #7 [f418df48] inet_shutdown at c080baf9
 #8 [f418df5c] sys_shutdown at c079eedf
 #9 [f418df70] sys_socketcall at c079fe88
    EAX: ffffffda  EBX: 0000000d  ECX: bfceea90  EDX: 0937af98
    DS:  007b      ESI: 0000000c  ES:  007b      EDI: b7150ae4
    SS:  007b      ESP: bfceea7c  EBP: bfceeaa8  GS:  0033
    CS:  0073      EIP: b775c424  ERR: 00000066  EFLAGS: 00000282

It appears that the side effect that starts the shutdown timer was processed
multiple times, which can happen as multiple paths can trigger it.  This of
course leads to the BUG halt in add_timer getting called.

Fix seems pretty straightforward, just check before the timer is added if its
already been started.  If it has mod the timer instead to min(current
expiration, new expiration)

Its been tested but not confirmed to fix the problem, as the issue has only
occured in production environments where test kernels are enjoined from being
installed.  It appears to be a sane fix to me though.  Also, recentely,
Jere found a reproducer posted on list to confirm that this resolves the
issues

Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
CC: Vlad Yasevich <vyasevich@gmail.com>
CC: "David S. Miller" <davem@davemloft.net>
CC: jere.leppanen@nokia.com
CC: marcelo.leitner@gmail.com
CC: netdev@vger.kernel.org
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-19 15:46:52 -07:00
Christoph Hellwig
3986912f6a ipv6: move SIOCADDRT and SIOCDELRT handling into ->compat_ioctl
To prepare removing the global routing_ioctl hack start lifting the code
into a newly added ipv6 ->compat_ioctl handler.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-05-18 17:35:02 -07:00
Daniel Borkmann
0b54142e4b Merge branch 'work.sysctl' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull in Christoph Hellwig's series that changes the sysctl's ->proc_handler
methods to take kernel pointers instead. It gets rid of the set_fs address
space overrides used by BPF. As per discussion, pull in the feature branch
into bpf-next as it relates to BPF sysctl progs.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20200427071508.GV23230@ZenIV.linux.org.uk/T/
2020-04-28 21:23:38 +02:00
Christoph Hellwig
32927393dc sysctl: pass kernel pointers to ->proc_handler
Instead of having all the sysctl handlers deal with user pointers, which
is rather hairy in terms of the BPF interaction, copy the input to and
from  userspace in common code.  This also means that the strings are
always NUL-terminated by the common code, making the API a little bit
safer.

As most handler just pass through the data to one of the common handlers
a lot of the changes are mechnical.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Andrey Ignatov <rdna@fb.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-27 02:07:40 -04:00
Jere Leppänen
12dfd78e3a sctp: Fix SHUTDOWN CTSN Ack in the peer restart case
When starting shutdown in sctp_sf_do_dupcook_a(), get the value for
SHUTDOWN Cumulative TSN Ack from the new association, which is
reconstructed from the cookie, instead of the old association, which
the peer doesn't have anymore.

Otherwise the SHUTDOWN is either ignored or replied to with an ABORT
by the peer because CTSN Ack doesn't match the peer's Initial TSN.

Fixes: bdf6fa52f0 ("sctp: handle association restarts when the socket is closed.")
Signed-off-by: Jere Leppänen <jere.leppanen@nokia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-22 19:27:40 -07:00
Jere Leppänen
145cb2f717 sctp: Fix bundling of SHUTDOWN with COOKIE-ACK
When we start shutdown in sctp_sf_do_dupcook_a(), we want to bundle
the SHUTDOWN with the COOKIE-ACK to ensure that the peer receives them
at the same time and in the correct order. This bundling was broken by
commit 4ff40b8626 ("sctp: set chunk transport correctly when it's a
new asoc"), which assigns a transport for the COOKIE-ACK, but not for
the SHUTDOWN.

Fix this by passing a reference to the COOKIE-ACK chunk as an argument
to sctp_sf_do_9_2_start_shutdown() and onward to
sctp_make_shutdown(). This way the SHUTDOWN chunk is assigned the same
transport as the COOKIE-ACK chunk, which allows them to be bundled.

In sctp_sf_do_9_2_start_shutdown(), the void *arg parameter was
previously unused. Now that we're taking it into use, it must be a
valid pointer to a chunk, or NULL. There is only one call site where
it's not, in sctp_sf_autoclose_timer_expire(). Fix that too.

Fixes: 4ff40b8626 ("sctp: set chunk transport correctly when it's a new asoc")
Signed-off-by: Jere Leppänen <jere.leppanen@nokia.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-04-22 19:27:40 -07:00
David S. Miller
5a470b1a63 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-03-30 20:48:43 -07:00
Marcelo Ricardo Leitner
582eea2305 sctp: fix possibly using a bad saddr with a given dst
Under certain circumstances, depending on the order of addresses on the
interfaces, it could be that sctp_v[46]_get_dst() would return a dst
with a mismatched struct flowi.

For example, if when walking through the bind addresses and the first
one is not a match, it saves the dst as a fallback (added in
410f03831c), but not the flowi. Then if the next one is also not a
match, the previous dst will be returned but with the flowi information
for the 2nd address, which is wrong.

The fix is to use a locally stored flowi that can be used for such
attempts, and copy it to the parameter only in case it is a possible
match, together with the corresponding dst entry.

The patch updates IPv6 code mostly just to be in sync. Even though the issue
is also present there, it fallback is not expected to work with IPv6.

Fixes: 410f03831c ("sctp: add routing output fallback")
Reported-by: Jin Meng <meng.a.jin@nokia-sbell.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 22:01:43 -07:00
Qiujun Huang
5c3e82fe15 sctp: fix refcount bug in sctp_wfree
We should iterate over the datamsgs to move
all chunks(skbs) to newsk.

The following case cause the bug:
for the trouble SKB, it was in outq->transmitted list

sctp_outq_sack
        sctp_check_transmitted
                SKB was moved to outq->sacked list
        then throw away the sack queue
                SKB was deleted from outq->sacked
(but it was held by datamsg at sctp_datamsg_to_asoc
So, sctp_wfree was not called here)

then migrate happened

        sctp_for_each_tx_datachunk(
        sctp_clear_owner_w);
        sctp_assoc_migrate();
        sctp_for_each_tx_datachunk(
        sctp_set_owner_w);
SKB was not in the outq, and was not changed to newsk

finally

__sctp_outq_teardown
        sctp_chunk_put (for another skb)
                sctp_datamsg_put
                        __kfree_skb(msg->frag_list)
                                sctp_wfree (for SKB)
	SKB->sk was still oldsk (skb->sk != asoc->base.sk).

Reported-and-tested-by: syzbot+cea71eec5d6de256d54d@syzkaller.appspotmail.com
Signed-off-by: Qiujun Huang <hqjagain@gmail.com>
Acked-by: Marcelo Ricardo Leitner <mleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-29 21:57:30 -07:00
David S. Miller
1d34357931 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Minor overlapping changes, nothing serious.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-12 22:34:48 -07:00
Dmitry Yakunin
83f73c5bb7 inet_diag: return classid for all socket types
In commit 1ec17dbd90 ("inet_diag: fix reporting cgroup classid and
fallback to priority") croup classid reporting was fixed. But this works
only for TCP sockets because for other socket types icsk parameter can
be NULL and classid code path is skipped. This change moves classid
handling to inet_diag_msg_attrs_fill() function.

Also inet_diag_msg_attrs_size() helper was added and addends in
nlmsg_new() were reordered to save order from inet_sk_diag_fill().

Fixes: 1ec17dbd90 ("inet_diag: fix reporting cgroup classid and fallback to priority")
Signed-off-by: Dmitry Yakunin <zeil@yandex-team.ru>
Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-03-08 21:57:48 -07:00
David S. Miller
9f0ca0c1a5 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
pull-request: bpf-next 2020-02-28

The following pull-request contains BPF updates for your *net-next* tree.

We've added 41 non-merge commits during the last 7 day(s) which contain
a total of 49 files changed, 1383 insertions(+), 499 deletions(-).

The main changes are:

1) BPF and Real-Time nicely co-exist.

2) bpftool feature improvements.

3) retrieve bpf_sk_storage via INET_DIAG.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-29 15:53:35 -08:00
Martin KaFai Lau
0df6d32842 inet_diag: Move the INET_DIAG_REQ_BYTECODE nlattr to cb->data
The INET_DIAG_REQ_BYTECODE nlattr is currently re-found every time when
the "dump()" is re-started.

In a latter patch, it will also need to parse the new
INET_DIAG_REQ_SK_BPF_STORAGES nlattr to learn the map_fds. Thus, this
patch takes this chance to store the parsed nlattr in cb->data
during the "start" time of a dump.

By doing this, the "bc" argument also becomes unnecessary
and is removed.  Also, the two copies of the INET_DIAG_REQ_BYTECODE
parsing-audit logic between compat/current version can be
consolidated to one.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200225230415.1975555-1-kafai@fb.com
2020-02-27 18:50:19 -08:00
Martin KaFai Lau
5682d393b4 inet_diag: Refactor inet_sk_diag_fill(), dump(), and dump_one()
In a latter patch, there is a need to update "cb->min_dump_alloc"
in inet_sk_diag_fill() as it learns the diffierent bpf_sk_storages
stored in a sk while dumping all sk(s) (e.g. tcp_hashinfo).

The inet_sk_diag_fill() currently does not take the "cb" as an argument.
One of the reason is inet_sk_diag_fill() is used by both dump_one()
and dump() (which belong to the "struct inet_diag_handler".  The dump_one()
interface does not pass the "cb" along.

This patch is to make dump_one() pass a "cb".  The "cb" is created in
inet_diag_cmd_exact().  The "nlh" and "in_skb" are stored in "cb" as
the dump() interface does.  The total number of args in
inet_sk_diag_fill() is also cut from 10 to 7 and
that helps many callers to pass fewer args.

In particular,
"struct user_namespace *user_ns", "u32 pid", and "u32 seq"
can be replaced by accessing "cb->nlh" and "cb->skb".

A similar argument reduction is also made to
inet_twsk_diag_fill() and inet_req_diag_fill().

inet_csk_diag_dump() and inet_csk_diag_fill() are also removed.
They are mostly equivalent to inet_sk_diag_fill().  Their repeated
usages are very limited.  Thus, inet_sk_diag_fill() is directly used
in those occasions.

Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200225230409.1975173-1-kafai@fb.com
2020-02-27 18:50:19 -08:00
Jules Irenge
b77b4f634e sctp: Add missing annotation for sctp_transport_walk_stop()
Sparse reports a warning at sctp_transport_walk_stop()

warning: context imbalance in sctp_transport_walk_stop
	- wrong count at exit

The root cause is the missing annotation at sctp_transport_walk_stop()
Add the missing __releases(RCU) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:26:49 -08:00
Jules Irenge
6c72b7740c sctp: Add missing annotation for sctp_transport_walk_start()
Sparse reports a warning at sctp_transport_walk_start()

warning: context imbalance in sctp_transport_walk_start
	- wrong count at exit

The root cause is the missing annotation at sctp_transport_walk_start()
Add the missing __acquires(RCU) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:26:48 -08:00
Jules Irenge
887cf3d139 sctp: Add missing annotation for sctp_err_finish()
Sparse reports a warning at sctp_err_finish()
warning: context imbalance in sctp_err_finish() - unexpected unlock

The root cause is a missing annotation at sctp_err_finish()
Add the missing  __releases(&((__sk)->sk_lock.slock)) annotation

Signed-off-by: Jules Irenge <jbi.octave@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-24 13:26:48 -08:00
Xin Long
245709ec8b sctp: move the format error check out of __sctp_sf_do_9_1_abort
When T2 timer is to be stopped, the asoc should also be deleted,
otherwise, there will be no chance to call sctp_association_free
and the asoc could last in memory forever.

However, in sctp_sf_shutdown_sent_abort(), after adding the cmd
SCTP_CMD_TIMER_STOP for T2 timer, it may return error due to the
format error from __sctp_sf_do_9_1_abort() and miss adding
SCTP_CMD_ASSOC_FAILED where the asoc will be deleted.

This patch is to fix it by moving the format error check out of
__sctp_sf_do_9_1_abort(), and do it before adding the cmd
SCTP_CMD_TIMER_STOP for T2 timer.

Thanks Hangbin for reporting this issue by the fuzz testing.

v1->v2:
  - improve the comment in the code as Marcelo's suggestion.

Fixes: 96ca468b86 ("sctp: check invalid value of length parameter in error cause")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-02-17 21:56:03 -08:00
David S. Miller
a2d6d7ae59 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The ungrafting from PRIO bug fixes in net, when merged into net-next,
merge cleanly but create a build failure.  The resolution used here is
from Petr Machata.

Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-09 12:13:43 -08:00
Xin Long
be7a772920 sctp: free cmd->obj.chunk for the unprocessed SCTP_CMD_REPLY
This patch is to fix a memleak caused by no place to free cmd->obj.chunk
for the unprocessed SCTP_CMD_REPLY. This issue occurs when failing to
process a cmd while there're still SCTP_CMD_REPLY cmds on the cmd seq
with an allocated chunk in cmd->obj.chunk.

So fix it by freeing cmd->obj.chunk for each SCTP_CMD_REPLY cmd left on
the cmd seq when any cmd returns error. While at it, also remove 'nomem'
label.

Reported-by: syzbot+107c4aff5f392bf1517f@syzkaller.appspotmail.com
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-06 13:28:37 -08:00
David S. Miller
31d518f35e Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Simple overlapping changes in bpf land wrt. bpf_helper_defs.h
handling.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-31 13:37:13 -08:00
Kevin Kou
f398efc14a sctp: add enabled check for path tracepoint loop.
sctp_outq_sack is the main function handles SACK, it is called very
frequently. As the commit "move trace_sctp_probe_path into sctp_outq_sack"
added below code to this function, sctp tracepoint is disabled most of time,
but the loop of transport list will be always called even though the
tracepoint is disabled, this is unnecessary.

+	/* SCTP path tracepoint for congestion control debugging. */
+	list_for_each_entry(transport, transport_list, transports) {
+		trace_sctp_probe_path(transport, asoc);
+	}

This patch is to add tracepoint enabled check at outside of the loop of
transport list, and avoid traversing the loop when trace is disabled,
it is a small optimization.

Signed-off-by: Kevin Kou <qdkevin.kou@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-30 20:33:05 -08:00
Kevin Kou
356b23c073 sctp: do trace_sctp_probe after SACK validation and check
The function sctp_sf_eat_sack_6_2 now performs the Verification
Tag validation, Chunk length validation, Bogu check, and also
the detection of out-of-order SACK based on the RFC2960
Section 6.2 at the beginning, and finally performs the further
processing of SACK. The trace_sctp_probe now triggered before
the above necessary validation and check.

this patch is to do the trace_sctp_probe after the chunk sanity
tests, but keep doing trace if the SACK received is out of order,
for the out-of-order SACK is valuable to congestion control
debugging.

v1->v2:
 - keep doing SCTP trace if the SACK is out of order as Marcelo's
   suggestion.
v2->v3:
 - regenerate the patch as v2 generated on top of v1, and add
   'net-next' tag to the new one as Marcelo's comments.

Signed-off-by: Kevin Kou <qdkevin.kou@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-27 16:34:51 -08:00
Kevin Kou
f643ee295c sctp: move trace_sctp_probe_path into sctp_outq_sack
The original patch bringed in the "SCTP ACK tracking trace event"
feature was committed at Dec.20, 2017, it replaced jprobe usage
with trace events, and bringed in two trace events, one is
TRACE_EVENT(sctp_probe), another one is TRACE_EVENT(sctp_probe_path).
The original patch intended to trigger the trace_sctp_probe_path in
TRACE_EVENT(sctp_probe) as below code,

+TRACE_EVENT(sctp_probe,
+
+	TP_PROTO(const struct sctp_endpoint *ep,
+		 const struct sctp_association *asoc,
+		 struct sctp_chunk *chunk),
+
+	TP_ARGS(ep, asoc, chunk),
+
+	TP_STRUCT__entry(
+		__field(__u64, asoc)
+		__field(__u32, mark)
+		__field(__u16, bind_port)
+		__field(__u16, peer_port)
+		__field(__u32, pathmtu)
+		__field(__u32, rwnd)
+		__field(__u16, unack_data)
+	),
+
+	TP_fast_assign(
+		struct sk_buff *skb = chunk->skb;
+
+		__entry->asoc = (unsigned long)asoc;
+		__entry->mark = skb->mark;
+		__entry->bind_port = ep->base.bind_addr.port;
+		__entry->peer_port = asoc->peer.port;
+		__entry->pathmtu = asoc->pathmtu;
+		__entry->rwnd = asoc->peer.rwnd;
+		__entry->unack_data = asoc->unack_data;
+
+		if (trace_sctp_probe_path_enabled()) {
+			struct sctp_transport *sp;
+
+			list_for_each_entry(sp, &asoc->peer.transport_addr_list,
+					    transports) {
+				trace_sctp_probe_path(sp, asoc);
+			}
+		}
+	),

But I found it did not work when I did testing, and trace_sctp_probe_path
had no output, I finally found that there is trace buffer lock
operation(trace_event_buffer_reserve) in include/trace/trace_events.h:

static notrace void							\
trace_event_raw_event_##call(void *__data, proto)			\
{									\
	struct trace_event_file *trace_file = __data;			\
	struct trace_event_data_offsets_##call __maybe_unused __data_offsets;\
	struct trace_event_buffer fbuffer;				\
	struct trace_event_raw_##call *entry;				\
	int __data_size;						\
									\
	if (trace_trigger_soft_disabled(trace_file))			\
		return;							\
									\
	__data_size = trace_event_get_offsets_##call(&__data_offsets, args); \
									\
	entry = trace_event_buffer_reserve(&fbuffer, trace_file,	\
				 sizeof(*entry) + __data_size);		\
									\
	if (!entry)							\
		return;							\
									\
	tstruct								\
									\
	{ assign; }							\
									\
	trace_event_buffer_commit(&fbuffer);				\
}

The reason caused no output of trace_sctp_probe_path is that
trace_sctp_probe_path written in TP_fast_assign part of
TRACE_EVENT(sctp_probe), and it will be placed( { assign; } ) after the
trace_event_buffer_reserve() when compiler expands Macro,

        entry = trace_event_buffer_reserve(&fbuffer, trace_file,        \
                                 sizeof(*entry) + __data_size);         \
                                                                        \
        if (!entry)                                                     \
                return;                                                 \
                                                                        \
        tstruct                                                         \
                                                                        \
        { assign; }                                                     \

so trace_sctp_probe_path finally can not acquire trace_event_buffer
and return no output, that is to say the nest of tracepoint entry function
is not allowed. The function call flow is:

trace_sctp_probe()
-> trace_event_raw_event_sctp_probe()
 -> lock buffer
 -> trace_sctp_probe_path()
   -> trace_event_raw_event_sctp_probe_path()  --nested
   -> buffer has been locked and return no output.

This patch is to remove trace_sctp_probe_path from the TP_fast_assign
part of TRACE_EVENT(sctp_probe) to avoid the nest of entry function,
and trigger sctp_probe_path_trace in sctp_outq_sack.

After this patch, you can enable both events individually,
  # cd /sys/kernel/debug/tracing
  # echo 1 > events/sctp/sctp_probe/enable
  # echo 1 > events/sctp/sctp_probe_path/enable

Or, you can enable all the events under sctp.

  # echo 1 > events/sctp/enable

Signed-off-by: Kevin Kou <qdkevin.kou@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-26 13:06:45 -08:00
Hangbin Liu
bd085ef678 net: add bool confirm_neigh parameter for dst_ops.update_pmtu
The MTU update code is supposed to be invoked in response to real
networking events that update the PMTU. In IPv6 PMTU update function
__ip6_rt_update_pmtu() we called dst_confirm_neigh() to update neighbor
confirmed time.

But for tunnel code, it will call pmtu before xmit, like:
  - tnl_update_pmtu()
    - skb_dst_update_pmtu()
      - ip6_rt_update_pmtu()
        - __ip6_rt_update_pmtu()
          - dst_confirm_neigh()

If the tunnel remote dst mac address changed and we still do the neigh
confirm, we will not be able to update neigh cache and ping6 remote
will failed.

So for this ip_tunnel_xmit() case, _EVEN_ if the MTU is changed, we
should not be invoking dst_confirm_neigh() as we have no evidence
of successful two-way communication at this point.

On the other hand it is also important to keep the neigh reachability fresh
for TCP flows, so we cannot remove this dst_confirm_neigh() call.

To fix the issue, we have to add a new bool parameter for dst_ops.update_pmtu
to choose whether we should do neigh update or not. I will add the parameter
in this patch and set all the callers to true to comply with the previous
way, and fix the tunnel code one by one on later patches.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Suggested-by: David Miller <davem@davemloft.net>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: David Ahern <dsahern@gmail.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24 22:28:54 -08:00
Marcelo Ricardo Leitner
61d5d40628 sctp: fix err handling of stream initialization
The fix on 951c6db954 fixed the issued reported there but introduced
another. When the allocation fails within sctp_stream_init() it is
okay/necessary to free the genradix. But it is also called when adding
new streams, from sctp_send_add_streams() and
sctp_process_strreset_addstrm_in() and in those situations it cannot
just free the genradix because by then it is a fully operational
association.

The fix here then is to only free the genradix in sctp_stream_init()
and on those other call sites  move on with what it already had and let
the subsequent error handling to handle it.

Tested with the reproducers from this report and the previous one,
with lksctp-tools and sctp-tests.

Reported-by: syzbot+9a1bc632e78a1a98488b@syzkaller.appspotmail.com
Fixes: 951c6db954 ("sctp: fix memleak on err handling of stream initialization")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-24 16:07:10 -08:00
David S. Miller
ac80010fc9 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Mere overlapping changes in the conflicts here.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-22 15:15:05 -08:00
Marcelo Ricardo Leitner
951c6db954 sctp: fix memleak on err handling of stream initialization
syzbot reported a memory leak when an allocation fails within
genradix_prealloc() for output streams. That's because
genradix_prealloc() leaves initialized members initialized when the
issue happens and SCTP stack will abort the current initialization but
without cleaning up such members.

The fix here is to always call genradix_free() when genradix_prealloc()
fails, for output and also input streams, as it suffers from the same
issue.

Reported-by: syzbot+772d9e36c490b18d51d1@syzkaller.appspotmail.com
Fixes: 2075e50caf ("sctp: convert to genradix")
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Tested-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-17 21:58:37 -08:00
Xin Long
4e7696d90b sctp: get netns from asoc and ep base
Commit 312434617c ("sctp: cache netns in sctp_ep_common") set netns
in asoc and ep base since they're created, and it will never change.
It's a better way to get netns from asoc and ep base, comparing to
calling sock_net().

This patch is to replace them.

v1->v2:
  - no change.

Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09 20:14:01 -08:00
Xin Long
b6f3320b1d sctp: fully initialize v4 addr in some functions
Syzbot found a crash:

  BUG: KMSAN: uninit-value in crc32_body lib/crc32.c:112 [inline]
  BUG: KMSAN: uninit-value in crc32_le_generic lib/crc32.c:179 [inline]
  BUG: KMSAN: uninit-value in __crc32c_le_base+0x4fa/0xd30 lib/crc32.c:202
  Call Trace:
    crc32_body lib/crc32.c:112 [inline]
    crc32_le_generic lib/crc32.c:179 [inline]
    __crc32c_le_base+0x4fa/0xd30 lib/crc32.c:202
    chksum_update+0xb2/0x110 crypto/crc32c_generic.c:90
    crypto_shash_update+0x4c5/0x530 crypto/shash.c:107
    crc32c+0x150/0x220 lib/libcrc32c.c:47
    sctp_csum_update+0x89/0xa0 include/net/sctp/checksum.h:36
    __skb_checksum+0x1297/0x12a0 net/core/skbuff.c:2640
    sctp_compute_cksum include/net/sctp/checksum.h:59 [inline]
    sctp_packet_pack net/sctp/output.c:528 [inline]
    sctp_packet_transmit+0x40fb/0x4250 net/sctp/output.c:597
    sctp_outq_flush_transports net/sctp/outqueue.c:1146 [inline]
    sctp_outq_flush+0x1823/0x5d80 net/sctp/outqueue.c:1194
    sctp_outq_uncork+0xd0/0xf0 net/sctp/outqueue.c:757
    sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1781 [inline]
    sctp_side_effects net/sctp/sm_sideeffect.c:1184 [inline]
    sctp_do_sm+0x8fe1/0x9720 net/sctp/sm_sideeffect.c:1155
    sctp_primitive_REQUESTHEARTBEAT+0x175/0x1a0 net/sctp/primitive.c:185
    sctp_apply_peer_addr_params+0x212/0x1d40 net/sctp/socket.c:2433
    sctp_setsockopt_peer_addr_params net/sctp/socket.c:2686 [inline]
    sctp_setsockopt+0x189bb/0x19090 net/sctp/socket.c:4672

The issue was caused by transport->ipaddr set with uninit addr param, which
was passed by:

  sctp_transport_init net/sctp/transport.c:47 [inline]
  sctp_transport_new+0x248/0xa00 net/sctp/transport.c:100
  sctp_assoc_add_peer+0x5ba/0x2030 net/sctp/associola.c:611
  sctp_process_param net/sctp/sm_make_chunk.c:2524 [inline]

where 'addr' is set by sctp_v4_from_addr_param(), and it doesn't initialize
the padding of addr->v4.

Later when calling sctp_make_heartbeat(), hbinfo.daddr(=transport->ipaddr)
will become the part of skb, and the issue occurs.

This patch is to fix it by initializing the padding of addr->v4 in
sctp_v4_from_addr_param(), as well as other functions that do the similar
thing, and these functions shouldn't trust that the caller initializes the
memory, as Marcelo suggested.

Reported-by: syzbot+6dcbfea81cd3d4dd0b02@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-09 10:16:39 -08:00
Sabrina Dubroca
c4e85f73af net: ipv6: add net argument to ip6_dst_lookup_flow
This will be used in the conversion of ipv6_stub to ip6_dst_lookup_flow,
as some modules currently pass a net argument without a socket to
ip6_dst_lookup. This is equivalent to commit 343d60aada ("ipv6: change
ipv6_stub_impl.ipv6_dst_lookup to take net argument").

Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-12-04 12:27:12 -08:00
Maciej Żenczykowski
82f31ebf61 net: port < inet_prot_sock(net) --> inet_port_requires_bind_service(net, port)
Note that the sysctl write accessor functions guarantee that:
  net->ipv4.sysctl_ip_prot_sock <= net->ipv4.ip_local_ports.range[0]
invariant is maintained, and as such the max() in selinux hooks is actually spurious.

ie. even though
  if (snum < max(inet_prot_sock(sock_net(sk)), low) || snum > high) {
per logic is the same as
  if ((snum < inet_prot_sock(sock_net(sk)) && snum < low) || snum > high) {
it is actually functionally equivalent to:
  if (snum < low || snum > high) {
which is equivalent to:
  if (snum < inet_prot_sock(sock_net(sk)) || snum < low || snum > high) {
even though the first clause is spurious.

But we want to hold on to it in case we ever want to change what what
inet_port_requires_bind_service() means (for example by changing
it from a, by default, [0..1024) range to some sort of set).

Test: builds, git 'grep inet_prot_sock' finds no other references
Cc: Eric Dumazet <edumazet@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 13:20:46 -08:00
Maciej Żenczykowski
fb8223888e net-sctp: replace some sock_net(sk) with just 'net'
It already existed in part of the function, but move it
to a higher level and use it consistently throughout.

Safe since sk is never written to.

Signed-off-by: Maciej Żenczykowski <maze@google.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-26 13:18:32 -08:00
David S. Miller
adf6f8cb3f Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Merge in networking bug fixes for merge window.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-25 14:57:26 -08:00
Xin Long
312434617c sctp: cache netns in sctp_ep_common
This patch is to fix a data-race reported by syzbot:

  BUG: KCSAN: data-race in sctp_assoc_migrate / sctp_hash_obj

  write to 0xffff8880b67c0020 of 8 bytes by task 18908 on cpu 1:
    sctp_assoc_migrate+0x1a6/0x290 net/sctp/associola.c:1091
    sctp_sock_migrate+0x8aa/0x9b0 net/sctp/socket.c:9465
    sctp_accept+0x3c8/0x470 net/sctp/socket.c:4916
    inet_accept+0x7f/0x360 net/ipv4/af_inet.c:734
    __sys_accept4+0x224/0x430 net/socket.c:1754
    __do_sys_accept net/socket.c:1795 [inline]
    __se_sys_accept net/socket.c:1792 [inline]
    __x64_sys_accept+0x4e/0x60 net/socket.c:1792
    do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
    entry_SYSCALL_64_after_hwframe+0x44/0xa9

  read to 0xffff8880b67c0020 of 8 bytes by task 12003 on cpu 0:
    sctp_hash_obj+0x4f/0x2d0 net/sctp/input.c:894
    rht_key_get_hash include/linux/rhashtable.h:133 [inline]
    rht_key_hashfn include/linux/rhashtable.h:159 [inline]
    rht_head_hashfn include/linux/rhashtable.h:174 [inline]
    head_hashfn lib/rhashtable.c:41 [inline]
    rhashtable_rehash_one lib/rhashtable.c:245 [inline]
    rhashtable_rehash_chain lib/rhashtable.c:276 [inline]
    rhashtable_rehash_table lib/rhashtable.c:316 [inline]
    rht_deferred_worker+0x468/0xab0 lib/rhashtable.c:420
    process_one_work+0x3d4/0x890 kernel/workqueue.c:2269
    worker_thread+0xa0/0x800 kernel/workqueue.c:2415
    kthread+0x1d4/0x200 drivers/block/aoe/aoecmd.c:1253
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:352

It was caused by rhashtable access asoc->base.sk when sctp_assoc_migrate
is changing its value. However, what rhashtable wants is netns from asoc
base.sk, and for an asoc, its netns won't change once set. So we can
simply fix it by caching netns since created.

Fixes: d6c0256a60 ("sctp: add the rhashtable apis for sctp global transport hashtable")
Reported-by: syzbot+e3b35fe7918ff0ee474e@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-11-23 18:26:14 -08:00
Navid Emamdoost
b6631c6031 sctp: Fix memory leak in sctp_sf_do_5_2_4_dupcook
In the implementation of sctp_sf_do_5_2_4_dupcook() the allocated
new_asoc is leaked if security_sctp_assoc_request() fails. Release it
via sctp_association_free().

Fixes: 2277c7cd75 ("sctp: Add LSM hooks")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
2019-11-23 18:20:17 -08:00
Xin Long
d467ac0a38 sctp: add SCTP_PEER_ADDR_THLDS_V2 sockopt
Section 7.2 of rfc7829: "Peer Address Thresholds (SCTP_PEER_ADDR_THLDS)
Socket Option" extends 'struct sctp_paddrthlds' with 'spt_pathcpthld'
added to allow a user to change ps_retrans per sock/asoc/transport, as
other 2 paddrthlds: pf_retrans, pathmaxrxt.

Note: to not break the user's program, here to support pf_retrans dump
and setting by adding a new sockopt SCTP_PEER_ADDR_THLDS_V2, and a new
structure sctp_paddrthlds_v2 instead of extending sctp_paddrthlds.

Also, when setting ps_retrans, the value is not allowed to be greater
than pf_retrans.

v1->v2:
  - use SCTP_PEER_ADDR_THLDS_V2 to set/get pf_retrans instead,
    as Marcelo and David Laight suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
34515e94c9 sctp: add support for Primary Path Switchover
This is a new feature defined in section 5 of rfc7829: "Primary Path
Switchover". By introducing a new tunable parameter:

  Primary.Switchover.Max.Retrans (PSMR)

The primary path will be changed to another active path when the path
error counter on the old primary path exceeds PSMR, so that "the SCTP
sender is allowed to continue data transmission on a new working path
even when the old primary destination address becomes active again".

This patch is to add this tunable parameter, 'ps_retrans' per netns,
sock, asoc and transport. It also allows a user to change ps_retrans
per netns by sysctl, and ps_retrans per sock/asoc/transport will be
initialized with it.

The check will be done in sctp_do_8_2_transport_strike() when this
feature is enabled.

Note this feature is disabled by initializing 'ps_retrans' per netns
as 0xffff by default, and its value can't be less than 'pf_retrans'
when changing by sysctl.

v3->v4:
  - add define SCTP_PS_RETRANS_MAX 0xffff, and use it on extra2 of
    sysctl 'ps_retrans'.
  - add a new entry for ps_retrans on ip-sysctl.txt.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
8d2a6935d8 sctp: add SCTP_EXPOSE_POTENTIALLY_FAILED_STATE sockopt
This is a sockopt defined in section 7.3 of rfc7829: "Exposing
the Potentially Failed Path State", by which users can change
pf_expose per sock and asoc.

The new sockopt SCTP_EXPOSE_POTENTIALLY_FAILED_STATE is also
known as SCTP_EXPOSE_PF_STATE for short.

v2->v3:
  - return -EINVAL if params.assoc_value > SCTP_PF_EXPOSE_MAX.
  - define SCTP_EXPOSE_PF_STATE SCTP_EXPOSE_POTENTIALLY_FAILED_STATE.
v3->v4:
  - improve changelog.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
768e15182d sctp: add SCTP_ADDR_POTENTIALLY_FAILED notification
SCTP Quick failover draft section 5.1, point 5 has been removed
from rfc7829. Instead, "the sender SHOULD (i) notify the Upper
Layer Protocol (ULP) about this state transition", as said in
section 3.2, point 8.

So this patch is to add SCTP_ADDR_POTENTIALLY_FAILED, defined
in section 7.1, "which is reported if the affected address
becomes PF". Also remove transport cwnd's update when moving
from PF back to ACTIVE , which is no longer in rfc7829 either.

Note that ulp_notify will be set to false if asoc->expose is
not 'enabled', according to last patch.

v2->v3:
  - define SCTP_ADDR_PF SCTP_ADDR_POTENTIALLY_FAILED.
v3->v4:
  - initialize spc_state with SCTP_ADDR_AVAILABLE, as Marcelo suggested.
  - check asoc->pf_expose in sctp_assoc_control_transport(), as Marcelo
    suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Xin Long
aef587be42 sctp: add pf_expose per netns and sock and asoc
As said in rfc7829, section 3, point 12:

  The SCTP stack SHOULD expose the PF state of its destination
  addresses to the ULP as well as provide the means to notify the
  ULP of state transitions of its destination addresses from
  active to PF, and vice versa.  However, it is recommended that
  an SCTP stack implementing SCTP-PF also allows for the ULP to be
  kept ignorant of the PF state of its destinations and the
  associated state transitions, thus allowing for retention of the
  simpler state transition model of [RFC4960] in the ULP.

Not only does it allow to expose the PF state to ULP, but also
allow to ignore sctp-pf to ULP.

So this patch is to add pf_expose per netns, sock and asoc. And in
sctp_assoc_control_transport(), ulp_notify will be set to false if
asoc->expose is not 'enabled' in next patch.

It also allows a user to change pf_expose per netns by sysctl, and
pf_expose per sock and asoc will be initialized with it.

Note that pf_expose also works for SCTP_GET_PEER_ADDR_INFO sockopt,
to not allow a user to query the state of a sctp-pf peer address
when pf_expose is 'disabled', as said in section 7.3.

v1->v2:
  - Fix a build warning noticed by Nathan Chancellor.
v2->v3:
  - set pf_expose to UNUSED by default to keep compatible with old
    applications.
v3->v4:
  - add a new entry for pf_expose on ip-sysctl.txt, as Marcelo suggested.
  - change this patch to 1/5, and move sctp_assoc_control_transport
    change into 2/5, as Marcelo suggested.
  - use SCTP_PF_EXPOSE_UNSET instead of SCTP_PF_EXPOSE_UNUSED, and
    set SCTP_PF_EXPOSE_UNSET to 0 in enum, as Marcelo suggested.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-08 14:18:32 -08:00
Eric Dumazet
099ecf59f0 net: annotate lockless accesses to sk->sk_max_ack_backlog
sk->sk_max_ack_backlog can be read without any lock being held
at least in TCP/DCCP cases.

We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing
and/or potential KCSAN warnings.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06 16:14:48 -08:00
Eric Dumazet
288efe8606 net: annotate lockless accesses to sk->sk_ack_backlog
sk->sk_ack_backlog can be read without any lock being held.
We need to use READ_ONCE()/WRITE_ONCE() to avoid load/store tearing
and/or potential KCSAN warnings.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06 16:14:48 -08:00
Eric Dumazet
7976a11b30 net: use helpers to change sk_ack_backlog
Writers are holding a lock, but many readers do not.

Following patch will add appropriate barriers in
sk_acceptq_removed() and sk_acceptq_added().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-06 16:14:48 -08:00
David S. Miller
d31e95585c Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
The only slightly tricky merge conflict was the netdevsim because the
mutex locking fix overlapped a lot of driver reload reorganization.

The rest were (relatively) trivial in nature.

Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-02 13:54:56 -07:00
Eric Dumazet
a904a0693c inet: stop leaking jiffies on the wire
Historically linux tried to stick to RFC 791, 1122, 2003
for IPv4 ID field generation.

RFC 6864 made clear that no matter how hard we try,
we can not ensure unicity of IP ID within maximum
lifetime for all datagrams with a given source
address/destination address/protocol tuple.

Linux uses a per socket inet generator (inet_id), initialized
at connection startup with a XOR of 'jiffies' and other
fields that appear clear on the wire.

Thiemo Nagel pointed that this strategy is a privacy
concern as this provides 16 bits of entropy to fingerprint
devices.

Let's switch to a random starting point, this is just as
good as far as RFC 6864 is concerned and does not leak
anything critical.

Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Thiemo Nagel <tnagel@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-11-01 14:57:52 -07:00
Eric Dumazet
3f926af3f4 net: use skb_queue_empty_lockless() in busy poll contexts
Busy polling usually runs without locks.
Let's use skb_queue_empty_lockless() instead of skb_queue_empty()

Also uses READ_ONCE() in __skb_try_recv_datagram() to address
a similar potential problem.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28 13:33:41 -07:00
Eric Dumazet
3ef7cf57c7 net: use skb_queue_empty_lockless() in poll() handlers
Many poll() handlers are lockless. Using skb_queue_empty_lockless()
instead of skb_queue_empty() is more appropriate.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2019-10-28 13:33:41 -07:00