Make sure that all external port are actually isolated from each other,
so no packets are leaked.

Fixes: ec6698c2 ("net: dsa: add support for Atheros AR9331 built-in switch")
Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hayes Wang says:

====================
r8169: adjust the setting for RTL8106e

These patches are uesed to avoid the delay of link-up interrupt, when
enabling ASPM for RTL8106e. The patch #1 is used to enable ASPM if
it is possible. And the patch #2 is used to modify the entrance latencies
of L0 and L1.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

The original L0 and L1 entrance latencies of RTL8106e are 4us. And
they cause the delay of link-up interrupt when enabling ASPM. Change
the L0 entrance latency to 7us and L1 entrance latency to 32us. Then,
they could avoid the issue.
Tested-by: Koba Ko <koba.ko@canonical.com>
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 1ee8856d.

This is used to re-enable ASPM on RTL8106e, if it is possible.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Daniel Borkmann says:

====================
pull-request: bpf 2021-08-07

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

We've added 4 non-merge commits during the last 9 day(s) which contain
a total of 4 files changed, 8 insertions(+), 7 deletions(-).

The main changes are:

1) Fix integer overflow in htab's lookup + delete batch op, from Tatsuhiko Yasumatsu.

2) Fix invalid fd 0 close in libbpf if BTF parsing failed, from Daniel Xu.

3) Fix libbpf feature probe for BPF_PROG_TYPE_CGROUP_SOCKOPT, from Robin Gögge.

4) Fix minor libbpf doc warning regarding code-block language, from Randy Dunlap.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

In __htab_map_lookup_and_delete_batch(), hash buckets are iterated
over to count the number of elements in each bucket (bucket_size).
If bucket_size is large enough, the multiplication to calculate
kvmalloc() size could overflow, resulting in out-of-bounds write
as reported by KASAN:

  [...]
  [  104.986052] BUG: KASAN: vmalloc-out-of-bounds in __htab_map_lookup_and_delete_batch+0x5ce/0xb60
  [  104.986489] Write of size 4194224 at addr ffffc9010503be70 by task crash/112
  [  104.986889]
  [  104.987193] CPU: 0 PID: 112 Comm: crash Not tainted 5.14.0-rc4 #13
  [  104.987552] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
  [  104.988104] Call Trace:
  [  104.988410]  dump_stack_lvl+0x34/0x44
  [  104.988706]  print_address_description.constprop.0+0x21/0x140
  [  104.988991]  ? __htab_map_lookup_and_delete_batch+0x5ce/0xb60
  [  104.989327]  ? __htab_map_lookup_and_delete_batch+0x5ce/0xb60
  [  104.989622]  kasan_report.cold+0x7f/0x11b
  [  104.989881]  ? __htab_map_lookup_and_delete_batch+0x5ce/0xb60
  [  104.990239]  kasan_check_range+0x17c/0x1e0
  [  104.990467]  memcpy+0x39/0x60
  [  104.990670]  __htab_map_lookup_and_delete_batch+0x5ce/0xb60
  [  104.990982]  ? __wake_up_common+0x4d/0x230
  [  104.991256]  ? htab_of_map_free+0x130/0x130
  [  104.991541]  bpf_map_do_batch+0x1fb/0x220
  [...]

In hashtable, if the elements' keys have the same jhash() value, the
elements will be put into the same bucket. By putting a lot of elements
into a single bucket, the value of bucket_size can be increased to
trigger the integer overflow.

Triggering the overflow is possible for both callers with CAP_SYS_ADMIN
and callers without CAP_SYS_ADMIN.

It will be trivial for a caller with CAP_SYS_ADMIN to intentionally
reach this overflow by enabling BPF_F_ZERO_SEED. As this flag will set
the random seed passed to jhash() to 0, it will be easy for the caller
to prepare keys which will be hashed into the same value, and thus put
all the elements into the same bucket.

If the caller does not have CAP_SYS_ADMIN, BPF_F_ZERO_SEED cannot be
used. However, it will be still technically possible to trigger the
overflow, by guessing the random seed value passed to jhash() (32bit)
and repeating the attempt to trigger the overflow. In this case,
the probability to trigger the overflow will be low and will take
a very long time.

Fix the integer overflow by calling kvmalloc_array() instead of
kvmalloc() to allocate memory.

Fixes: 05799638 ("bpf: Add batch ops to all htab bpf map")
Signed-off-by: Tatsuhiko Yasumatsu <th.yasumatsu@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210806150419.109658-1-th.yasumatsu@gmail.com

Use "code-block: none" instead of "c" for non-C-language code blocks.
Removes these warnings:

  lnx-514-rc4/Documentation/bpf/libbpf/libbpf_naming_convention.rst:111: WARNING: Could not lex literal_block as "c". Highlighting skipped.
  lnx-514-rc4/Documentation/bpf/libbpf/libbpf_naming_convention.rst:124: WARNING: Could not lex literal_block as "c". Highlighting skipped.

Fixes: f42cfb46 ("bpf: Add documentation for libbpf including API autogen")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20210802015037.787-1-rdunlap@infradead.org

Before this patch, btf_new() was liable to close an arbitrary FD 0 if
BTF parsing failed. This was because:

* btf->fd was initialized to 0 through the calloc()
* btf__free() (in the `done` label) closed any FDs >= 0
* btf->fd is left at 0 if parsing fails

This issue was discovered on a system using libbpf v0.3 (without
BTF_KIND_FLOAT support) but with a kernel that had BTF_KIND_FLOAT types
in BTF. Thus, parsing fails.

While this patch technically doesn't fix any issues b/c upstream libbpf
has BTF_KIND_FLOAT support, it'll help prevent issues in the future if
more BTF types are added. It also allow the fix to be backported to
older libbpf's.

Fixes: 3289959b ("libbpf: Support BTF loading and raw data output in both endianness")
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/5969bb991adedb03c6ae93e051fd2a00d293cf25.1627513670.git.dxu@dxuuu.xyz

This patch fixes the probe for BPF_PROG_TYPE_CGROUP_SOCKOPT,
so the probe reports accurate results when used by e.g.
bpftool.

Fixes: 4cdbfb59 ("libbpf: support sockopt hooks")
Signed-off-by: Robin Gögge <r.goegge@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Link: https://lore.kernel.org/bpf/20210728225825.2357586-1-r.goegge@gmail.com

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for net:

1) Restrict range element expansion in ipset to avoid soft lockup,
   from Jozsef Kadlecsik.

2) Memleak in error path for nf_conntrack_bridge for IPv4 packets,
   from Yajun Deng.

3) Simplify conntrack garbage collection strategy to avoid frequent
   wake-ups, from Florian Westphal.

4) Fix NFNLA_HOOK_FUNCTION_NAME string, do not include module name.

5) Missing chain family netlink attribute in chain description
   in nfnetlink_hook.

6) Incorrect sequence number on nfnetlink_hook dumps.

7) Use netlink request family in reply message for consistency.

8) Remove offload_pickup sysctl, use conntrack for established state
   instead, from Florian Westphal.

9) Translate NFPROTO_INET/ingress to NFPROTO_NETDEV/ingress, since
   NFPROTO_INET is not exposed through nfnetlink_hook.

* git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf:
  netfilter: nfnetlink_hook: translate inet ingress to netdev
  netfilter: conntrack: remove offload_pickup sysctl again
  netfilter: nfnetlink_hook: Use same family as request message
  netfilter: nfnetlink_hook: use the sequence number of the request message
  netfilter: nfnetlink_hook: missing chain family
  netfilter: nfnetlink_hook: strip off module name from hookfn
  netfilter: conntrack: collect all entries in one cycle
  netfilter: nf_conntrack_bridge: Fix memory leak when error
  netfilter: ipset: Limit the maximal range of consecutive elements to add/delete
====================

Link: https://lore.kernel.org/r/20210806151149.6356-1-pablo@netfilter.orgSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The NFPROTO_INET pseudofamily is not exposed through this new netlink
interface. The netlink dump either shows NFPROTO_IPV4 or NFPROTO_IPV6
for NFPROTO_INET prerouting/input/forward/output/postrouting hooks.
The NFNLA_CHAIN_FAMILY attribute provides the family chain, which
specifies if this hook applies to inet traffic only (either IPv4 or
IPv6).

Translate the inet/ingress hook to netdev/ingress to fully hide the
NFPROTO_INET implementation details.

Fixes: e2cf17d3 ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

These two sysctls were added because the hardcoded defaults (2 minutes,
tcp, 30 seconds, udp) turned out to be too low for some setups.

They appeared in 5.14-rc1 so it should be fine to remove it again.

Marcelo convinced me that there should be no difference between a flow
that was offloaded vs. a flow that was not wrt. timeout handling.
Thus the default is changed to those for TCP established and UDP stream,
5 days and 120 seconds, respectively.

Marcelo also suggested to account for the timeout value used for the
offloading, this avoids increase beyond the value in the conntrack-sysctl
and will also instantly expire the conntrack entry with altered sysctls.

Example:
   nf_conntrack_udp_timeout_stream=60
   nf_flowtable_udp_timeout=60

This will remove offloaded udp flows after one minute, rather than two.

An earlier version of this patch also cleared the ASSURED bit to
allow nf_conntrack to evict the entry via early_drop (i.e., table full).
However, it looks like we can safely assume that connection timed out
via HW is still in established state, so this isn't needed.

Quoting Oz:
 [..] the hardware sends all packets with a set FIN flags to sw.
 [..] Connections that are aged in hardware are expected to be in the
 established state.

In case it turns out that back-to-sw-path transition can occur for
'dodgy' connections too (e.g., one side disappeared while software-path
would have been in RETRANS timeout), we can adjust this later.

Cc: Oz Shlomo <ozsh@nvidia.com>
Cc: Paul Blakey <paulb@nvidia.com>
Suggested-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reviewed-by: Oz Shlomo <ozsh@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Use the same family as the request message, for consistency. The
netlink payload provides sufficient information to describe the hook
object, including the family.

This makes it easier to userspace to correlate the hooks are that
visited by the packets for a certain family.

Fixes: e2cf17d3 ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The sequence number allows to correlate the netlink reply message (as
part of the dump) with the original request message.

The cb->seq field is internally used to detect an interference (update)
of the hook list during the netlink dump, do not use it as sequence
number in the netlink dump header.

Fixes: e2cf17d3 ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The family is relevant for pseudo-families like NFPROTO_INET
otherwise the user needs to rely on the hook function name to
differentiate it from NFPROTO_IPV4 and NFPROTO_IPV6 names.

Add nfnl_hook_chain_desc_attributes instead of using the existing
NFTA_CHAIN_* attributes, since these do not provide a family number.

Fixes: e2cf17d3 ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

NFNLA_HOOK_FUNCTION_NAME should include the hook function name only,
the module name is already provided by NFNLA_HOOK_MODULE_NAME.

Fixes: e2cf17d3 ("netfilter: add new hook nfnl subsystem")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Michal Kubecek reports that conntrack gc is responsible for frequent
wakeups (every 125ms) on idle systems.

On busy systems, timed out entries are evicted during lookup.
The gc worker is only needed to remove entries after system becomes idle
after a busy period.

To resolve this, always scan the entire table.
If the scan is taking too long, reschedule so other work_structs can run
and resume from next bucket.

After a completed scan, wait for 2 minutes before the next cycle.
Heuristics for faster re-schedule are removed.

GC_SCAN_INTERVAL could be exposed as a sysctl in the future to allow
tuning this as-needed or even turn the gc worker off.
Reported-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

On s390, the following build warning occurs:

drivers/net/ethernet/marvell/mvpp2/mvpp2.h:844:2: warning: overflow in
conversion from 'long unsigned int' to 'int' changes value from
'18446744073709551584' to '-32' [-Woverflow]
844 |  ((total_size) - MVPP2_SKB_HEADROOM - MVPP2_SKB_SHINFO_SIZE)

This happens because MVPP2_SKB_SHINFO_SIZE, which is 320 bytes (which is
already 64-byte aligned) on some architectures, actually gets ALIGN'd up
to 512 bytes in the s390 case.

So then, when this is invoked:

    MVPP2_RX_MAX_PKT_SIZE(MVPP2_BM_SHORT_FRAME_SIZE)

...that turns into:

     704 - 224 - 512 == -32

...which is not a good frame size to end up with! The warning above is a
bit lucky: it notices a signed/unsigned bad behavior here, which leads
to the real problem of a frame that is too short for its contents.

Increase MVPP2_BM_SHORT_FRAME_SIZE by 32 (from 704 to 736), which is
just exactly big enough. (The other values can't readily be changed
without causing a lot of other problems.)

Fixes: 07dd0a7a ("mvpp2: add basic XDP support")
Cc: Sven Auhagen <sven.auhagen@voleatech.de>
Cc: Matteo Croce <mcroce@microsoft.com>
Cc: David S. Miller <davem@davemloft.net>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add the missing RxUnicast counter.

Fixes: b8f126a8 ("net-next: dsa: add dsa support for Mediatek MT7530 switch")
Signed-off-by: DENG Qingfang <dqfext@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull networking fixes from Jakub Kicinski:
 "Including fixes from ipsec.

  Current release - regressions:

   - sched: taprio: fix init procedure to avoid inf loop when dumping

   - sctp: move the active_key update after sh_keys is added

  Current release - new code bugs:

   - sparx5: fix build with old GCC & bitmask on 32-bit targets

  Previous releases - regressions:

   - xfrm: redo the PREEMPT_RT RCU vs hash_resize_mutex deadlock fix

   - xfrm: fixes for the compat netlink attribute translator

   - phy: micrel: Fix detection of ksz87xx switch

  Previous releases - always broken:

   - gro: set inner transport header offset in tcp/udp GRO hook to avoid
     crashes when such packets reach GSO

   - vsock: handle VIRTIO_VSOCK_OP_CREDIT_REQUEST, as required by spec

   - dsa: sja1105: fix static FDB entries on SJA1105P/Q/R/S and SJA1110

   - bridge: validate the NUD_PERMANENT bit when adding an extern_learn
     FDB entry

   - usb: lan78xx: don't modify phy_device state concurrently

   - usb: pegasus: check for errors of IO routines"

* tag 'net-5.14-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (48 commits)
  net: vxge: fix use-after-free in vxge_device_unregister
  net: fec: fix use-after-free in fec_drv_remove
  net: pegasus: fix uninit-value in get_interrupt_interval
  net: ethernet: ti: am65-cpsw: fix crash in am65_cpsw_port_offload_fwd_mark_update()
  bnx2x: fix an error code in bnx2x_nic_load()
  net: wwan: iosm: fix recursive lock acquire in unregister
  net: wwan: iosm: correct data protocol mask bit
  net: wwan: iosm: endianness type correction
  net: wwan: iosm: fix lkp buildbot warning
  net: usb: lan78xx: don't modify phy_device state concurrently
  docs: networking: netdevsim rules
  net: usb: pegasus: Remove the changelog and DRIVER_VERSION.
  net: usb: pegasus: Check the return value of get_geristers() and friends;
  net/prestera: Fix devlink groups leakage in error flow
  net: sched: fix lockdep_set_class() typo error for sch->seqlock
  net: dsa: qca: ar9331: reorder MDIO write sequence
  VSOCK: handle VIRTIO_VSOCK_OP_CREDIT_REQUEST
  mptcp: drop unused rcu member in mptcp_pm_addr_entry
  net: ipv6: fix returned variable type in ip6_skb_dst_mtu
  nfp: update ethtool reporting of pauseframe control
  ...

syzbot is hitting might_sleep() warning at hci_sock_dev_event() due to
calling lock_sock() with rw spinlock held [1].

It seems that history of this locking problem is a trial and error.

Commit b40df574 ("[PATCH] bluetooth: fix socket locking in
hci_sock_dev_event()") in 2.6.21-rc4 changed bh_lock_sock() to
lock_sock() as an attempt to fix lockdep warning.

Then, commit 4ce61d1c ("[BLUETOOTH]: Fix locking in
hci_sock_dev_event().") in 2.6.22-rc2 changed lock_sock() to
local_bh_disable() + bh_lock_sock_nested() as an attempt to fix the
sleep in atomic context warning.

Then, commit 4b5dd696 ("Bluetooth: Remove local_bh_disable() from
hci_sock.c") in 3.3-rc1 removed local_bh_disable().

Then, commit e305509e ("Bluetooth: use correct lock to prevent UAF
of hdev object") in 5.13-rc5 again changed bh_lock_sock_nested() to
lock_sock() as an attempt to fix CVE-2021-3573.

This difficulty comes from current implementation that
hci_sock_dev_event(HCI_DEV_UNREG) is responsible for dropping all
references from sockets because hci_unregister_dev() immediately
reclaims resources as soon as returning from
hci_sock_dev_event(HCI_DEV_UNREG).

But the history suggests that hci_sock_dev_event(HCI_DEV_UNREG) was not
doing what it should do.

Therefore, instead of trying to detach sockets from device, let's accept
not detaching sockets from device at hci_sock_dev_event(HCI_DEV_UNREG),
by moving actual cleanup of resources from hci_unregister_dev() to
hci_cleanup_dev() which is called by bt_host_release() when all
references to this unregistered device (which is a kobject) are gone.

Since hci_sock_dev_event(HCI_DEV_UNREG) no longer resets
hci_pi(sk)->hdev, we need to check whether this device was unregistered
and return an error based on HCI_UNREGISTER flag.  There might be subtle
behavioral difference in "monitor the hdev" functionality; please report
if you found something went wrong due to this patch.

Link: https://syzkaller.appspot.com/bug?extid=a5df189917e79d5e59c9 [1]
Reported-by: syzbot <syzbot+a5df189917e79d5e59c9@syzkaller.appspotmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Fixes: e305509e ("Bluetooth: use correct lock to prevent UAF of hdev object")
Acked-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pull selinux fix from Paul Moore:
 "One small SELinux fix for a problem where an error code was not being
  propagated back up to userspace when a bogus SELinux policy is loaded
  into the kernel"

* tag 'selinux-pr-20210805' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
  selinux: correct the return value when loads initial sids

Pull ucounts fix from Eric Biederman:
 "Fix a subtle locking versus reference counting bug in the ucount
  changes, found by syzbot"

* 'for-v5.14' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace:
  ucounts: Fix race condition between alloc_ucounts and put_ucounts

Pull tracing fixes from Steven Rostedt:
 "Various tracing fixes:

   - Fix NULL pointer dereference caused by an error path

   - Give histogram calculation fields a size, otherwise it breaks
     synthetic creation based on them.

   - Reject strings being used for number calculations.

   - Fix recordmcount.pl warning on llvm building RISC-V allmodconfig

   - Fix the draw_functrace.py script to handle the new trace output

   - Fix warning of smp_processor_id() in preemptible code"

* tag 'trace-v5.14-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Quiet smp_processor_id() use in preemptable warning in hwlat
  scripts/tracing: fix the bug that can't parse raw_trace_func
  scripts/recordmcount.pl: Remove check_objcopy() and $can_use_local
  tracing: Reject string operand in the histogram expression
  tracing / histogram: Give calculation hist_fields a size
  tracing: Fix NULL pointer dereference in start_creating

Pull s390 fixes from Heiko Carstens:

 - fix zstd build for -march=z900 (undefined reference to __clzdi2)

 - add missing .got.plts to vdso linker scripts to fix kpatch build
   errors

 - update defconfigs

* tag 's390-5.14-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390: update defconfigs
  s390/boot: fix zstd build for -march=z900
  s390/vdso: add .got.plt in vdso linker script

Pull kvm fixes from Paolo Bonzini:
 "Mostly bugfixes; plus, support for XMM arguments to Hyper-V hypercalls
  now obeys KVM_CAP_HYPERV_ENFORCE_CPUID.

  Both the XMM arguments feature and KVM_CAP_HYPERV_ENFORCE_CPUID are
  new in 5.14, and each did not know of the other"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: x86/mmu: Fix per-cpu counter corruption on 32-bit builds
  KVM: selftests: fix hyperv_clock test
  KVM: SVM: improve the code readability for ASID management
  KVM: SVM: Fix off-by-one indexing when nullifying last used SEV VMCB
  KVM: Do not leak memory for duplicate debugfs directories
  KVM: selftests: Test access to XMM fast hypercalls
  KVM: x86: hyper-v: Check if guest is allowed to use XMM registers for hypercall input
  KVM: x86: Introduce trace_kvm_hv_hypercall_done()
  KVM: x86: hyper-v: Check access to hypercall before reading XMM registers
  KVM: x86: accept userspace interrupt only if no event is injected

Pull pcmcia fix from Dominik Brodowski:
 "Zheyu Ma found and fixed a null pointer dereference bug in the device
  driver for the i82092 card reader"

* 'pcmcia-next' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/linux:
  pcmcia: i82092: fix a null pointer dereference bug

This program always prints 4096 and hangs before the patch, and always
prints 8192 and exits successfully after:

  int main()
  {
      int pipefd[2];
      for (int i = 0; i < 1025; i++)
          if (pipe(pipefd) == -1)
              return 1;
      size_t bufsz = fcntl(pipefd[1], F_GETPIPE_SZ);
      printf("%zd\n", bufsz);
      char *buf = calloc(bufsz, 1);
      write(pipefd[1], buf, bufsz);
      read(pipefd[0], buf, bufsz-1);
      write(pipefd[1], buf, 1);
  }

Note that you may need to increase your RLIMIT_NOFILE before running the
program.

Fixes: 759c0114 ("pipe: limit the per-user amount of pages allocated in pipes")
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/lkml/1628086770.5rn8p04n6j.none@localhost/
Link: https://lore.kernel.org/lkml/1628127094.lxxn016tj7.none@localhost/Signed-off-by: Alex Xu (Hello71) <alex_y_xu@yahoo.ca>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Pavel Skripkin says:

====================
net: fix use-after-free bugs

I've added new checker to smatch yesterday. It warns about using
netdev_priv() pointer after free_{netdev,candev}() call. I hope, it will
get into next smatch release.

Some of the reported bugs are fixed and upstreamed already, but Dan ran new
smatch with allmodconfig and found 2 more. Big thanks to Dan for doing it,
because I totally forgot to do it.
====================

Link: https://lore.kernel.org/r/cover.1628091954.git.paskripkin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

Smatch says:
drivers/net/ethernet/neterion/vxge/vxge-main.c:3518 vxge_device_unregister() error: Using vdev after free_{netdev,candev}(dev);
drivers/net/ethernet/neterion/vxge/vxge-main.c:3518 vxge_device_unregister() error: Using vdev after free_{netdev,candev}(dev);
drivers/net/ethernet/neterion/vxge/vxge-main.c:3520 vxge_device_unregister() error: Using vdev after free_{netdev,candev}(dev);
drivers/net/ethernet/neterion/vxge/vxge-main.c:3520 vxge_device_unregister() error: Using vdev after free_{netdev,candev}(dev);

Since vdev pointer is netdev private data accessing it after free_netdev()
call can cause use-after-free bug. Fix it by moving free_netdev() call at
the end of the function

Fixes: 6cca2003 ("vxge: cleanup probe error paths")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Smatch says:
	drivers/net/ethernet/freescale/fec_main.c:3994 fec_drv_remove() error: Using fep after free_{netdev,candev}(ndev);
	drivers/net/ethernet/freescale/fec_main.c:3995 fec_drv_remove() error: Using fep after free_{netdev,candev}(ndev);

Since fep pointer is netdev private data, accessing it after free_netdev()
call can cause use-after-free bug. Fix it by moving free_netdev() call at
the end of the function
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Fixes: a31eda65 ("net: fec: fix clock count mis-match")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Reviewed-by: Joakim Zhang <qiangqing.zhang@nxp.com>
Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Syzbot reported uninit value pegasus_probe(). The problem was in missing
error handling.

get_interrupt_interval() internally calls read_eprom_word() which can
fail in some cases. For example: failed to receive usb control message.
These cases should be handled to prevent uninit value bug, since
read_eprom_word() will not initialize passed stack variable in case of
internal failure.

Fail log:

BUG: KMSAN: uninit-value in get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline]
BUG: KMSAN: uninit-value in pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152
CPU: 1 PID: 825 Comm: kworker/1:1 Not tainted 5.12.0-rc6-syzkaller #0
...
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:79 [inline]
 dump_stack+0x24c/0x2e0 lib/dump_stack.c:120
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5c/0xa0 mm/kmsan/kmsan_instr.c:197
 get_interrupt_interval drivers/net/usb/pegasus.c:746 [inline]
 pegasus_probe+0x10e7/0x4080 drivers/net/usb/pegasus.c:1152
....

Local variable ----data.i@pegasus_probe created at:
 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline]
 pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152
 get_interrupt_interval drivers/net/usb/pegasus.c:1151 [inline]
 pegasus_probe+0xe57/0x4080 drivers/net/usb/pegasus.c:1152

Reported-and-tested-by: syzbot+02c9f70f3afae308464a@syzkaller.appspotmail.com
Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Signed-off-by: Pavel Skripkin <paskripkin@gmail.com>
Link: https://lore.kernel.org/r/20210804143005.439-1-paskripkin@gmail.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

The hardware latency detector (hwlat) has a mode that it runs one thread
across CPUs. The logic to move from the currently running CPU to the next
one in the list does a smp_processor_id() to find where it currently is.
Unfortunately, it's done with preemption enabled, and this triggers a
warning for using smp_processor_id() in a preempt enabled section.

As it is only using smp_processor_id() to get information on where it
currently is in order to simply move it to the next CPU, it doesn't really
care if it got moved in the mean time. It will simply balance out later if
such a case arises.

Switch smp_processor_id() to raw_smp_processor_id() to quiet that warning.

Link: https://lkml.kernel.org/r/20210804141848.79edadc0@oasis.local.homeAcked-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Fixes: 8fa826b7 ("trace/hwlat: Implement the mode config option")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The am65_cpsw_port_offload_fwd_mark_update() causes NULL exception crash
when there is at least one disabled port and any other port added to the
bridge first time.

Unable to handle kernel NULL pointer dereference at virtual address 0000000000000858
pc : am65_cpsw_port_offload_fwd_mark_update+0x54/0x68
lr : am65_cpsw_netdevice_event+0x8c/0xf0
Call trace:
am65_cpsw_port_offload_fwd_mark_update+0x54/0x68
notifier_call_chain+0x54/0x98
raw_notifier_call_chain+0x14/0x20
call_netdevice_notifiers_info+0x34/0x78
__netdev_upper_dev_link+0x1c8/0x290
netdev_master_upper_dev_link+0x1c/0x28
br_add_if+0x3f0/0x6d0 [bridge]

Fix it by adding proper check for port->ndev != NULL.

Fixes: 2934db9b ("net: ti: am65-cpsw-nuss: Add netdevice notifiers")
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Set the error code if bnx2x_alloc_fw_stats_mem() fails.  The current
code returns success.

Fixes: ad5afc89 ("bnx2x: Separate VF and PF logic")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

M Chetan Kumar says:

====================
net: wwan: iosm: fixes

This patch series contains IOSM Driver fixes. Below is the patch
series breakdown.

PATCH1:
* Correct the td buffer type casting & format specifier to fix lkp buildbot
warning.

PATCH2:
* Endianness type correction for nr_of_bytes. This field is exchanged
as part of host-device protocol communication.

PATCH3:
* Correct ul/dl data protocol mask bit to know which protocol capability
does device implement.

PATCH4:
* Calling unregister_netdevice() inside wwan del link is trying to
acquire the held lock in ndo_stop_cb(). Instead, queue net dev to
be unregistered later.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Calling unregister_netdevice() inside wwan del link is trying to
acquire the held lock in ndo_stop_cb(). Instead, queue net dev to
be unregistered later.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Correct ul/dl data protocol mask bit to know which protocol capability
does device implement.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Endianness type correction for nr_of_bytes. This field is exchanged
as part of host-device protocol communication.
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Reviewed-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Correct td buffer type casting & format specifier to fix lkp buildbot
warning.
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: M Chetan Kumar <m.chetan.kumar@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>