When skb->len==0, the recv_actor() returns 0 too, but we also use 0
for error conditions. This patch amends this by propagating the errors
to tcp_read_skb() so that we can distinguish skb->len==0 case from
error cases.

Fixes: 04919bed948d ("tcp: Introduce tcp_read_skb()")
Reported-by: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

As tcp_read_skb() only reads one skb at a time, the while loop is
unnecessary, we can turn it into an if. This also simplifies the
code logic.

Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

tcp_cleanup_rbuf() retrieves the skb from sk_receive_queue, it
assumes the skb is not yet dequeued. This is no longer true for
tcp_read_skb() case where we dequeue the skb first.

Fix this by introducing a helper __tcp_cleanup_rbuf() which does
not require any skb and calling it in tcp_read_skb().

Fixes: 04919bed948d ("tcp: Introduce tcp_read_skb()")
Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Before commit 965b57b469a5 ("net: Introduce a new proto_ops
->read_skb()"), skb was not dequeued from receive queue hence
when we close TCP socket skb can be just flushed synchronously.

After this commit, we have to uncharge skb immediately after being
dequeued, otherwise it is still charged in the original sock. And we
still need to retain skb->sk, as eBPF programs may extract sock
information from skb->sk. Therefore, we have to call
skb_set_owner_sk_safe() here.

Fixes: 965b57b469a5 ("net: Introduce a new proto_ops ->read_skb()")
Reported-and-tested-by: syzbot+a0e6f8738b58f7654417@syzkaller.appspotmail.com
Tested-by: Stanislav Fomichev <sdf@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Pull driver core / kernfs updates from Greg KH:
 "Here is the set of driver core and kernfs changes for 6.0-rc1.

  The "biggest" thing in here is some scalability improvements for
  kernfs for large systems. Other than that, included in here are:

   - arch topology and cache info changes that have been reviewed and
     discussed a lot.

   - potential error path cleanup fixes

   - deferred driver probe cleanups

   - firmware loader cleanups and tweaks

   - documentation updates

   - other small things

  All of these have been in the linux-next tree for a while with no
  reported problems"

* tag 'driver-core-6.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (63 commits)
  docs: embargoed-hardware-issues: fix invalid AMD contact email
  firmware_loader: Replace kmap() with kmap_local_page()
  sysfs docs: ABI: Fix typo in comment
  kobject: fix Kconfig.debug "its" grammar
  kernfs: Fix typo 'the the' in comment
  docs: driver-api: firmware: add driver firmware guidelines. (v3)
  arch_topology: Fix cache attributes detection in the CPU hotplug path
  ACPI: PPTT: Leave the table mapped for the runtime usage
  cacheinfo: Use atomic allocation for percpu cache attributes
  drivers/base: fix userspace break from using bin_attributes for cpumap and cpulist
  MAINTAINERS: Change mentions of mpm to olivia
  docs: ABI: sysfs-devices-soc: Update Lee Jones' email address
  docs: ABI: sysfs-class-pwm: Update Lee Jones' email address
  Documentation/process: Add embargoed HW contact for LLVM
  Revert "kernfs: Change kernfs_notify_list to llist."
  ACPI: Remove the unused find_acpi_cpu_cache_topology()
  arch_topology: Warn that topology for nested clusters is not supported
  arch_topology: Add support for parsing sockets in /cpu-map
  arch_topology: Set cluster identifier in each core/thread from /cpu-map
  arch_topology: Limit span of cpu_clustergroup_mask()
  ...

__udp_sysctl_init() is called for init_net via udp_sysctl_ops.

While at it, we can rename __udp_sysctl_init() to udp_sysctl_init().

Fixes: 1e8029515816 ("udp: Move the udp sysctl to namespace.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

No conflicts.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

After the blamed commit, IPv4 SYN packets handled
by a dual stack IPv6 socket are dropped, even if
perfectly valid.

$ nstat | grep MD5
TcpExtTCPMD5Failure             5                  0.0

For a dual stack listener, an incoming IPv4 SYN packet
would call tcp_inbound_md5_hash() with @family == AF_INET,
while tp->af_specific is pointing to tcp_sock_ipv6_specific.

Only later when an IPv4-mapped child is created, tp->af_specific
is changed to tcp_sock_ipv6_mapped_specific.

Fixes: 7bbb765b7349 ("net/tcp: Merge TCP-MD5 inbound callbacks")
Reported-by: Brian Vazquez <brianvv@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Dmitry Safonov <dima@arista.com>
Tested-by: Leonard Crestez <cdleonard@gmail.com>
Link: https://lore.kernel.org/r/20220726115743.2759832-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Expose TCP rx queue accessor and cleanup, so that TLS can
decrypt directly from the TCP queue. The expectation
is that the caller can access the skb returned from
tcp_recv_skb() and up to inq bytes worth of data (some
of which may be in ->next skbs) and then call
tcp_read_done() when data has been consumed.
The socket lock must be held continuously across
those two operations.

Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Steffen Klassert says:

====================
pull request (net-next): ipsec-next 2022-07-20

1) Don't set DST_NOPOLICY in IPv4, a recent patch made this
   superfluous. From Eyal Birger.

2) Convert alg_key to flexible array member to avoid an iproute2
   compile warning when built with gcc-12.
   From Stephen Hemminger.

3) xfrm_register_km and xfrm_unregister_km do always return 0
   so change the type to void. From Zhengchao Shao.

4) Fix spelling mistake in esp6.c
   From Zhang Jiaming.

5) Improve the wording of comment above XFRM_OFFLOAD flags.
   From Petr Vaněk.

Please pull or let me know if there are problems.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>