linux-toradex.git/net/dccp, branch v5.16

tcp: switch orphan_count to bare per-cpu counters

2021-10-15T10:28:34+00:00

Use of percpu_counter structure to track count of orphaned
sockets is causing problems on modern hosts with 256 cpus
or more.

Stefan Bach reported a serious spinlock contention in real workloads,
that I was able to reproduce with a netfilter rule dropping
incoming FIN packets.

    53.56%  server  [kernel.kallsyms]      [k] queued_spin_lock_slowpath
            |
            ---queued_spin_lock_slowpath
               |
                --53.51%--_raw_spin_lock_irqsave
                          |
                           --53.51%--__percpu_counter_sum
                                     tcp_check_oom
                                     |
                                     |--39.03%--__tcp_close
                                     |          tcp_close
                                     |          inet_release
                                     |          inet6_release
                                     |          sock_close
                                     |          __fput
                                     |          ____fput
                                     |          task_work_run
                                     |          exit_to_usermode_loop
                                     |          do_syscall_64
                                     |          entry_SYSCALL_64_after_hwframe
                                     |          __GI___libc_close
                                     |
                                      --14.48%--tcp_out_of_resources
                                                tcp_write_timeout
                                                tcp_retransmit_timer
                                                tcp_write_timer_handler
                                                tcp_write_timer
                                                call_timer_fn
                                                expire_timers
                                                __run_timers
                                                run_timer_softirq
                                                __softirqentry_text_start

As explained in commit cf86a086a180 ("net/dst: use a smaller percpu_counter
batch for dst entries accounting"), default batch size is too big
for the default value of tcp_max_orphans (262144).

But even if we reduce batch sizes, there would still be cases
where the estimated count of orphans is beyond the limit,
and where tcp_too_many_orphans() has to call the expensive
percpu_counter_sum_positive().

One solution is to use plain per-cpu counters, and have
a timer to periodically refresh this cache.

Updating this cache every 100ms seems about right, tcp pressure
state is not radically changing over shorter periods.

percpu_counter was nice 15 years ago while hosts had less
than 16 cpus, not anymore by current standards.

v2: Fix the build issue for CONFIG_CRYPTO_DEV_CHELSIO_TLS=m,
    reported by kernel test robot 
    Remove unused socket argument from tcp_too_many_orphans()

Fixes: dd24c00191d5 ("net: Use a percpu_counter for orphan_count")
Signed-off-by: Eric Dumazet 
Reported-by: Stefan Bach 
Cc: Neal Cardwell 
Acked-by: Neal Cardwell 
Signed-off-by: David S. Miller

dccp: don't duplicate ccid when cloning dccp sock

2021-09-08T10:28:35+00:00

Commit 2677d2067731 ("dccp: don't free ccid2_hc_tx_sock ...") fixed
a UAF but reintroduced CVE-2017-6074.

When the sock is cloned, two dccps_hc_tx_ccid will reference to the
same ccid. So one can free the ccid object twice from two socks after
cloning.

This issue was found by "Hadar Manor" as well and assigned with
CVE-2020-16119, which was fixed in Ubuntu's kernel. So here I port
the patch from Ubuntu to fix it.

The patch prevents cloned socks from referencing the same ccid.

Fixes: 2677d2067731410 ("dccp: don't free ccid2_hc_tx_sock ...")
Signed-off-by: Zhenpeng Lin 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2021-08-13T13:41:22+00:00

Conflicts:

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
  9e26680733d5 ("bnxt_en: Update firmware call to retrieve TX PTP timestamp")
  9e518f25802c ("bnxt_en: 1PPS functions to configure TSIO pins")
  099fdeda659d ("bnxt_en: Event handler for PPS events")

kernel/bpf/helpers.c
include/linux/bpf-cgroup.h
  a2baf4e8bb0f ("bpf: Fix potentially incorrect results with bpf_get_local_storage()")
  c7603cfa04e7 ("bpf: Add ambient BPF runtime context stored in current")

drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
  5957cc557dc5 ("net/mlx5: Set all field of mlx5_irq before inserting it to the xarray")
  2d0b41a37679 ("net/mlx5: Refcount mlx5_irq with integer")

MAINTAINERS
  7b637cd52f02 ("MAINTAINERS: fix Microchip CAN BUS Analyzer Tool entry typo")
  7d901a1e878a ("net: phy: add Maxlinear GPY115/21x/24x driver")

Signed-off-by: Jakub Kicinski

dccp: add do-while-0 stubs for dccp_pr_debug macros

2021-08-09T09:00:02+00:00

GCC complains about empty macros in an 'if' statement, so convert
them to 'do {} while (0)' macros.

Fixes these build warnings:

net/dccp/output.c: In function 'dccp_xmit_packet':
../net/dccp/output.c:283:71: warning: suggest braces around empty body in an 'if' statement [-Wempty-body]
  283 |                 dccp_pr_debug("transmit_skb() returned err=%d\n", err);
net/dccp/ackvec.c: In function 'dccp_ackvec_update_old':
../net/dccp/ackvec.c:163:80: warning: suggest braces around empty body in an 'else' statement [-Wempty-body]
  163 |                                               (unsigned long long)seqno, state);

Fixes: dc841e30eaea ("dccp: Extend CCID packet dequeueing interface")
Fixes: 380240864451 ("dccp ccid-2: Update code for the Ack Vector input/registration routine")
Signed-off-by: Randy Dunlap 
Cc: dccp@vger.kernel.org
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Cc: Gerrit Renker 
Signed-off-by: David S. Miller

memcg: enable accounting for inet_bin_bucket cache

2021-07-20T13:00:38+00:00

net namespace can create up to 64K tcp and dccp ports and force kernel
to allocate up to several megabytes of memory per netns
for inet_bind_bucket objects.

It makes sense to account for them to restrict the host's memory
consumption from inside the memcg-limited container.

Signed-off-by: Vasily Averin 
Signed-off-by: David S. Miller

net: sock: introduce sk_error_report

2021-06-29T18:28:21+00:00

This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.

Signed-off-by: Alexander Aring 
Signed-off-by: David S. Miller

dccp: tfrc: fix doc warnings in tfrc_equation.c

2021-06-10T21:08:49+00:00

Add description for `tfrc_invert_loss_event_rate` to fix the W=1 warnings:

 net/dccp/ccids/lib/tfrc_equation.c:695: warning: Function parameter or
  member 'loss_event_rate' not described in 'tfrc_invert_loss_event_rate'

Signed-off-by: Baokun Li 
Reviewed-by: Richard Sailer 
Signed-off-by: David S. Miller

net: Remove the member netns_ok

2021-05-17T22:29:35+00:00

Every protocol has the 'netns_ok' member and it is euqal to 1. The
'if (!prot->netns_ok)' always false in inet_add_protocol().

Signed-off-by: Yejune Deng 
Signed-off-by: David S. Miller

net: dccp: use net_generic storage

2021-04-09T23:34:56+00:00

DCCP is virtually never used, so no need to use space in struct net for it.

Put the pernet ipv4/v6 socket in the dccp ipv4/ipv6 modules instead.

Signed-off-by: Florian Westphal 
Link: https://lore.kernel.org/r/20210408174502.1625-1-fw@strlen.de
Signed-off-by: Jakub Kicinski

ipv6: weaken the v4mapped source check

2021-03-18T18:19:23+00:00

This reverts commit 6af1799aaf3f1bc8defedddfa00df3192445bbf3.

Commit 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped
source address") introduced an input check against v4mapped addresses.
Use of such addresses on the wire is indeed questionable and not
allowed on public Internet. As the commit pointed out

  https://tools.ietf.org/html/draft-itojun-v6ops-v4mapped-harmful-02

lists potential issues.

Unfortunately there are applications which use v4mapped addresses,
and breaking them is a clear regression. For example v4mapped
addresses (or any semi-valid addresses, really) may be used
for uni-direction event streams or packet export.

Since the issue which sparked the addition of the check was with
TCP and request_socks in particular push the check down to TCPv6
and DCCP. This restores the ability to receive UDPv6 packets with
v4mapped address as the source.

Keep using the IPSTATS_MIB_INHDRERRORS statistic to minimize the
user-visible changes.

Fixes: 6af1799aaf3f ("ipv6: drop incoming packets having a v4mapped source address")
Reported-by: Sunyi Shao 
Signed-off-by: Jakub Kicinski 
Acked-by: Mat Martineau 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller