So we can track the field status and move it after tail.

After this commit the skb lifecycle for simple cases (no ct, no secmark,
no vlan, no UDP tunnel) uses 3 cacheline instead of 4 cachelines required
before this series.

e.g. GRO for non vlan traffic will consistently uses 3 cacheline for
each packet.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Such field validity is already tracked by the existing
'vlan_present' bit. Move them after tail and conditinally copy
as needed.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

all the inner header fields are valid only if the 'encaspulation'
flag is set, and the relevant fields are always initialized when
the field is set: we don't need to initialize them at skb allocation
time

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Leveraging the previous patch we can now avoid orphaning the
skb in the veth gro path, allowing correct backpressure.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

This change leverages the infrastructure introduced by the previous
patches to allow soft devices passing to the GRO engine owned skbs
without impacting the fast-path.

It's up to the GRO caller ensuring the bit validity before
invoking the GRO engine with the new helper skb_prepare_for_gro().

If the bit is set only skb with equal sk will be aggregated.
Additionally, skb truesize on GRO recycle and free is correctly
updated so that sk wmem is not changed by the GRO processing.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

After the previous patches, at GRO time, skb->_state is
usually 0, unless the packets comes from some H/W offload
slowpath or tunnel without rx checksum offload.

We can optimize the GRO code assuming !skb->_state is likely.
This remove multiple conditionals in the fast-path, at the
price of an additional one when we hit the above "slow-paths".

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

No functional change intended

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

Similar to the previous patch, covering the dst field,
but limited to tracking only the dst status.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

so that we can skip initizialzing such field at skb
allocation and move such field after 'tail'.

_state uses one byte hole in the header section.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>

In nf_tables_commit, if nf_tables_commit_audit_alloc fails, it does not
free the adp variable.

Fix this by adding nf_tables_commit_audit_free which frees
the linked list with the head node adl.

backtrace:
  kmalloc include/linux/slab.h:591 [inline]
  kzalloc include/linux/slab.h:721 [inline]
  nf_tables_commit_audit_alloc net/netfilter/nf_tables_api.c:8439 [inline]
  nf_tables_commit+0x16e/0x1760 net/netfilter/nf_tables_api.c:8508
  nfnetlink_rcv_batch+0x512/0xa80 net/netfilter/nfnetlink.c:562
  nfnetlink_rcv_skb_batch net/netfilter/nfnetlink.c:634 [inline]
  nfnetlink_rcv+0x1fa/0x220 net/netfilter/nfnetlink.c:652
  netlink_unicast_kernel net/netlink/af_netlink.c:1314 [inline]
  netlink_unicast+0x2c7/0x3e0 net/netlink/af_netlink.c:1340
  netlink_sendmsg+0x36b/0x6b0 net/netlink/af_netlink.c:1929
  sock_sendmsg_nosec net/socket.c:702 [inline]
  sock_sendmsg+0x56/0x80 net/socket.c:722

Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: kernel test robot <lkp@intel.com>
Fixes: c520292 ("audit: log nftables configuration change events once per table")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

The release_sock() is blocking function, it would change the state
after sleeping. use wait_woken() instead.

Fixes: 1da177e ("Linux-2.6.12-rc2")
Signed-off-by: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>

According to reference guides mt7530 (mt7620) and mt7531:

NOTE: When IVL is reset, MAC[47:0] and FID[2:0] will be used to
read/write the address table. When IVL is set, MAC[47:0] and CVID[11:0]
will be used to read/write the address table.

Since the function only fills in CVID and no FID, we need to set the
IVL bit. The existing code does not set it.

This is a fix for the issue I dropped here earlier:

http://lists.infradead.org/pipermail/linux-mediatek/2021-June/025697.html

With this patch, it is now possible to delete the 'self' fdb entry
manually. However, wifi roaming still has the same issue, the entry
does not get deleted automatically. Wifi roaming also needs a fix
somewhere else to function correctly in combination with vlan.

Signed-off-by: Eric Woudstra <ericwouds@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

As Alexander points out, when we are trying to recycle a cloned/expanded
SKB we might trigger a race.  The recycling code relies on the
pp_recycle bit to trigger,  which we carry over to cloned SKBs.
If that cloned SKB gets expanded or if we get references to the frags,
call skb_release_data() and overwrite skb->head, we are creating separate
instances accessing the same page frags.  Since the skb_release_data()
will first try to recycle the frags,  there's a potential race between
the original and cloned SKB, since both will have the pp_recycle bit set.

Fix this by explicitly those SKBs not recyclable.
The atomic_sub_return effectively limits us to a single release case,
and when we are calling skb_release_data we are also releasing the
option to perform the recycling, or releasing the pages from the page pool.

Fixes: 6a5bcd8 ("page_pool: Allow drivers to hint on SKB recycling")
Reported-by: Alexander Duyck <alexanderduyck@fb.com>
Suggested-by: Alexander Duyck <alexanderduyck@fb.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Andrii Nakryiko says:

====================
pull-request: bpf 2021-07-15

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

We've added 9 non-merge commits during the last 5 day(s) which contain
a total of 9 files changed, 37 insertions(+), 15 deletions(-).

The main changes are:

1) Fix NULL pointer dereference in BPF_TEST_RUN for BPF_XDP_DEVMAP and
   BPF_XDP_CPUMAP programs, from Xuan Zhuo.

2) Fix use-after-free of net_device in XDP bpf_link, from Xuan Zhuo.

3) Follow-up fix to subprog poke descriptor use-after-free problem, from
   Daniel Borkmann and John Fastabend.

4) Fix out-of-range array access in s390 BPF JIT backend, from Colin Ian King.

5) Fix memory leak in BPF sockmap, from John Fastabend.

6) Fix for sockmap to prevent proc stats reporting bug, from John Fastabend
   and Jakub Sitnicki.

7) Fix NULL pointer dereference in bpftool, from Tobias Klauser.

8) AF_XDP documentation fixes, from Baruch Siach.
====================

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

The current error handling code of hso_create_net_device is
hso_free_net_device, no matter which errors lead to. For example,
WARNING in hso_free_net_device [1].

Fix this by refactoring the error handling code of
hso_create_net_device by handling different errors by different code.

[1] https://syzkaller.appspot.com/bug?id=66eff8d49af1b28370ad342787413e35bbe76efe

Reported-by: syzbot+44d53c7255bb1aea22d2@syzkaller.appspotmail.com
Fixes: 5fcfb6d ("hso: fix bailout in error case of probe")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Liajian reported a bug_on hit on a ThunderX2 arm64 server with FastLinQ
QL41000 ethernet controller:
 BUG: scheduling while atomic: kworker/0:4/531/0x00000200
  [qed_probe:488()]hw prepare failed
  kernel BUG at mm/vmalloc.c:2355!
  Internal error: Oops - BUG: 0 [#1] SMP
  CPU: 0 PID: 531 Comm: kworker/0:4 Tainted: G W 5.4.0-77-generic torvalds#86-Ubuntu
  pstate: 00400009 (nzcv daif +PAN -UAO)
 Call trace:
  vunmap+0x4c/0x50
  iounmap+0x48/0x58
  qed_free_pci+0x60/0x80 [qed]
  qed_probe+0x35c/0x688 [qed]
  __qede_probe+0x88/0x5c8 [qede]
  qede_probe+0x60/0xe0 [qede]
  local_pci_probe+0x48/0xa0
  work_for_cpu_fn+0x24/0x38
  process_one_work+0x1d0/0x468
  worker_thread+0x238/0x4e0
  kthread+0xf0/0x118
  ret_from_fork+0x10/0x18

In this case, qed_hw_prepare() returns error due to hw/fw error, but in
theory work queue should be in process context instead of interrupt.

The root cause might be the unpaired spin_{un}lock_bh() in
_qed_mcp_cmd_and_union(), which causes botton half is disabled incorrectly.

Reported-by: Lijian Zhang <Lijian.Zhang@arm.com>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When nr_segs equal to zero in iovec_from_user, the object
msg->msg_iter.iov is uninit stack memory in caif_seqpkt_sendmsg
which is defined in ___sys_sendmsg. So we cann't just judge
msg->msg_iter.iov->base directlly. We can use nr_segs to judge
msg in caif_seqpkt_sendmsg whether has data buffers.

=====================================================
BUG: KMSAN: uninit-value in caif_seqpkt_sendmsg+0x693/0xf60 net/caif/caif_socket.c:542
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 caif_seqpkt_sendmsg+0x693/0xf60 net/caif/caif_socket.c:542
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2343
 ___sys_sendmsg net/socket.c:2397 [inline]
 __sys_sendmmsg+0x808/0xc90 net/socket.c:2480
 __compat_sys_sendmmsg net/compat.c:656 [inline]

Reported-by: syzbot+09a5d591c1f98cf5efcb@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=1ace85e8fc9b0d5a45c08c2656c3e91762daa9b8
Fixes: bece7b2 ("caif: Rewritten socket implementation")
Signed-off-by: Ziyang Xuan <william.xuanziyang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Fix and add a missing NULL check for the prior malloc() call.

Fixes: 49a086c ("bpftool: implement prog load command")
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Roman Gushchin <guro@fb.com>
Link: https://lore.kernel.org/bpf/20210715110609.29364-1-tklauser@distanz.ch

The proc socket stats use sk_prot->inuse_idx value to record inuse sock
stats. We currently do not set this correctly from sockmap side. The
result is reading sock stats '/proc/net/sockstat' gives incorrect values.
The socket counter is incremented correctly, but because we don't set the
counter correctly when we replace sk_prot we may omit the decrement.

To get the correct inuse_idx value move the core_initcall that initializes
the UDP proto handlers to late_initcall. This way it is initialized after
UDP has the chance to assign the inuse_idx value from the register protocol
handler.

Fixes: edc6741 ("bpf: Add sockmap hooks for UDP sockets")
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20210714154750.528206-1-jakub@cloudflare.com

The proc socket stats use sk_prot->inuse_idx value to record inuse sock
stats. We currently do not set this correctly from sockmap side. The
result is reading sock stats '/proc/net/sockstat' gives incorrect values.
The socket counter is incremented correctly, but because we don't set the
counter correctly when we replace sk_prot we may omit the decrement.

To get the correct inuse_idx value move the core_initcall that initializes
the TCP proto handlers to late_initcall. This way it is initialized after
TCP has the chance to assign the inuse_idx value from the register protocol
handler.

Fixes: 604326b ("bpf, sockmap: convert to generic sk_msg interface")
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/bpf/20210712195546.423990-3-john.fastabend@gmail.com

If skb_linearize is needed and fails we could leak a msg on the error
handling. To fix ensure we kfree the msg block before returning error.
Found during code review.

Fixes: 4363023 ("bpf, sockmap: Avoid failures from skb_to_sgvec when skb has frag_list")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Link: https://lore.kernel.org/bpf/20210712195546.423990-2-john.fastabend@gmail.com

Currently array jit->seen_reg[r1] is being accessed before the range
checking of index r1. The range changing on r1 should be performed
first since it will avoid any potential out-of-range accesses on the
array seen_reg[] and also it is more optimal to perform checks on r1
before fetching data from the array. Fix this by swapping the order
of the checks before the array access.

Fixes: 0546231 ("s390/bpf: Add s390x eBPF JIT compiler backend")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/20210715125712.24690-1-colin.king@canonical.com

Tracepoint trace_qdisc_enqueue() is introduced to trace skb at
the entrance of TC layer on TX side. This is similar to
trace_qdisc_dequeue():

1. For both we only trace successful cases. The failure cases
   can be traced via trace_kfree_skb().

2. They are called at entrance or exit of TC layer, not for each
   ->enqueue() or ->dequeue(). This is intentional, because
   we want to make trace_qdisc_enqueue() symmetric to
   trace_qdisc_dequeue(), which is easier to use.

The return value of qdisc_enqueue() is not interesting here,
we have Qdisc's drop packets in ->dequeue(), it is impossible to
trace them even if we have the return value, the only way to trace
them is tracing kfree_skb().

We only add information we need to trace ring buffer. If any other
information is needed, it is easy to extend it without breaking ABI,
see commit 3dd344e ("net: tracepoint: exposing sk_family in all
tcp:tracepoints").

Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Qitao Xu <qitao.xu@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Print format of skbaddr is changed to %px from %p, because we want
to use skb address as a quick way to identify a packet.

Note, trace ring buffer is only accessible to privileged users,
it is safe to use a real kernel address here.

Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Qitao Xu <qitao.xu@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

The print format of skb adress in tracepoint class net_dev_template
is changed to %px from %p, because we want to use skb address
as a quick way to identify a packet.

Note, trace ring buffer is only accessible to privileged users,
it is safe to use a real kernel address here.

Reviewed-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: Qitao Xu <qitao.xu@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Shifting the u16 integer oct->pcie_port by CN23XX_PKT_INPUT_CTL_MAC_NUM_POS
(29) bits will be promoted to a 32 bit signed int and then sign-extended
to a u64. In the cases where oct->pcie_port where bit 2 is set (e.g. 3..7)
the shifted value will be sign extended and the top 32 bits of the result
will be set.

Fix this by casting the u16 values to a u64 before the 29 bit left shift.

Addresses-Coverity: ("Unintended sign extension")

Fixes: 3451b97 ("liquidio: CN23XX register setup")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

…V88E6XXX

Making global2 support mandatory removed the Kconfig symbol
NET_DSA_MV88E6XXX_GLOBAL2.  This symbol also served as an intermediate
symbol to make NET_DSA_MV88E6XXX_PTP depend on NET_DSA_MV88E6XXX.  With
the symbol removed, the user is always asked about PTP support for
Marvell 88E6xxx switches, even if the latter support is not enabled.

Fix this by reinstating the dependency.

Fixes: 63368a7 ("net: dsa: mv88e6xxx: Make global2 support mandatory")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Takashi Iwai says:

====================
r8152: Fix a couple of PM problems

it seems that r8152 driver suffers from the deadlock at both runtime
and system PM.  Formerly, it was seen more often at hibernation
resume, but now it's triggered more frequently, as reported in SUSE
Bugzilla:
  https://bugzilla.suse.com/show_bug.cgi?id=1186194

While debugging the problem, I stumbled on a few obvious bugs and here
is the results with two patches for addressing the resume problem.

***

However, the story doesn't end here, unfortunately, and those patches
don't seem sufficing.  The rest major problem is that the driver calls
napi_disable() and napi_enable() in the PM suspend callbacks.  This
makes the system stalling at (runtime-)suspend.  If we drop
napi_disable() and napi_enable() calls in the PM suspend callbacks, it
starts working (that was the result in Bugzilla comment 13):
  https://bugzilla.suse.com/show_bug.cgi?id=1186194#c13

So, my patches aren't enough and we still need to investigate
further.  It'd be appreciated if anyone can give a fix or a hint for
more debugging.  The usage of napi_disable() at PM callbacks is unique
in this driver and looks rather suspicious to me; but I'm no expert in
this area so I might be wrong...
====================

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

r8152 driver sets up the MAC address at reset-resume, while
rtl8152_set_mac_address() has the temporary autopm get/put.  This may
lead to a deadlock as the PM lock has been already taken for the
execution of the runtime PM callback.

This patch adds the workaround to avoid the superfluous autpm when
called from rtl8152_reset_resume().

Link: https://bugzilla.suse.com/show_bug.cgi?id=1186194
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

rtl8152_close() takes the refcount via usb_autopm_get_interface() but
it doesn't release when RTL8152_UNPLUG test hits.  This may lead to
the imbalance of PM refcount.  This patch addresses it.

Link: https://bugzilla.suse.com/show_bug.cgi?id=1186194
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

…/git/netdev/net

Pull networking fixes from Jakub Kicinski.
 "Including fixes from bpf and netfilter.

  Current release - regressions:

   - sock: fix parameter order in sock_setsockopt()

  Current release - new code bugs:

   - netfilter: nft_last:
       - fix incorrect arithmetic when restoring last used
       - honor NFTA_LAST_SET on restoration

  Previous releases - regressions:

   - udp: properly flush normal packet at GRO time

   - sfc: ensure correct number of XDP queues; don't allow enabling the
     feature if there isn't sufficient resources to Tx from any CPU

   - dsa: sja1105: fix address learning getting disabled on the CPU port

   - mptcp: addresses a rmem accounting issue that could keep packets in
     subflow receive buffers longer than necessary, delaying MPTCP-level
     ACKs

   - ip_tunnel: fix mtu calculation for ETHER tunnel devices

   - do not reuse skbs allocated from skbuff_fclone_cache in the napi
     skb cache, we'd try to return them to the wrong slab cache

   - tcp: consistently disable header prediction for mptcp

  Previous releases - always broken:

   - bpf: fix subprog poke descriptor tracking use-after-free

   - ipv6:
       - allocate enough headroom in ip6_finish_output2() in case
         iptables TEE is used
       - tcp: drop silly ICMPv6 packet too big messages to avoid
         expensive and pointless lookups (which may serve as a DDOS
         vector)
       - make sure fwmark is copied in SYNACK packets
       - fix 'disable_policy' for forwarded packets (align with IPv4)

   - netfilter: conntrack:
       - do not renew entry stuck in tcp SYN_SENT state
       - do not mark RST in the reply direction coming after SYN packet
         for an out-of-sync entry

   - mptcp: cleanly handle error conditions with MP_JOIN and syncookies

   - mptcp: fix double free when rejecting a join due to port mismatch

   - validate lwtstate->data before returning from skb_tunnel_info()

   - tcp: call sk_wmem_schedule before sk_mem_charge in zerocopy path

   - mt76: mt7921: continue to probe driver when fw already downloaded

   - bonding: fix multiple issues with offloading IPsec to (thru?) bond

   - stmmac: ptp: fix issues around Qbv support and setting time back

   - bcmgenet: always clear wake-up based on energy detection

  Misc:

   - sctp: move 198 addresses from unusable to private scope

   - ptp: support virtual clocks and timestamping

   - openvswitch: optimize operation for key comparison"

* tag 'net-5.14-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (158 commits)
  net: dsa: properly check for the bridge_leave methods in dsa_switch_bridge_leave()
  sfc: add logs explaining XDP_TX/REDIRECT is not available
  sfc: ensure correct number of XDP queues
  sfc: fix lack of XDP TX queues - error XDP TX failed (-22)
  net: fddi: fix UAF in fza_probe
  net: dsa: sja1105: fix address learning getting disabled on the CPU port
  net: ocelot: fix switchdev objects synced for wrong netdev with LAG offload
  net: Use nlmsg_unicast() instead of netlink_unicast()
  octeontx2-pf: Fix uninitialized boolean variable pps
  ipv6: allocate enough headroom in ip6_finish_output2()
  net: hdlc: rename 'mod_init' & 'mod_exit' functions to be module-specific
  net: bridge: multicast: fix MRD advertisement router port marking race
  net: bridge: multicast: fix PIM hello router port marking race
  net: phy: marvell10g: fix differentiation of 88X3310 from 88X3340
  dsa: fix for_each_child.cocci warnings
  virtio_net: check virtqueue_add_sgs() return value
  mptcp: properly account bulk freed memory
  selftests: mptcp: fix case multiple subflows limited by server
  mptcp: avoid processing packet if a subflow reset
  mptcp: fix syncookie process if mptcp can not_accept new subflow
  ...

Add a simple helper that filesystems can use in their parameter parser
to parse the "source" parameter. A few places open-coded this function
and that already caused a bug in the cgroup v1 parser that we fixed.
Let's make it harder to get this wrong by introducing a helper which
performs all necessary checks.

Link: https://syzkaller.appspot.com/bug?id=6312526aba5beae046fdae8f00399f87aab48b12
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

The following sequence can be used to trigger a UAF:

    int fscontext_fd = fsopen("cgroup");
    int fd_null = open("/dev/null, O_RDONLY);
    int fsconfig(fscontext_fd, FSCONFIG_SET_FD, "source", fd_null);
    close_range(3, ~0U, 0);

The cgroup v1 specific fs parser expects a string for the "source"
parameter.  However, it is perfectly legitimate to e.g.  specify a file
descriptor for the "source" parameter.  The fs parser doesn't know what
a filesystem allows there.  So it's a bug to assume that "source" is
always of type fs_value_is_string when it can reasonably also be
fs_value_is_file.

This assumption in the cgroup code causes a UAF because struct
fs_parameter uses a union for the actual value.  Access to that union is
guarded by the param->type member.  Since the cgroup paramter parser
didn't check param->type but unconditionally moved param->string into
fc->source a close on the fscontext_fd would trigger a UAF during
put_fs_context() which frees fc->source thereby freeing the file stashed
in param->file causing a UAF during a close of the fd_null.

Fix this by verifying that param->type is actually a string and report
an error if not.

In follow up patches I'll add a new generic helper that can be used here
and by other filesystems instead of this error-prone copy-pasta fix.
But fixing it in here first makes backporting a it to stable a lot
easier.

Fixes: 8d2451f ("cgroup1: switch to option-by-option parsing")
Reported-by: syzbot+283ce5a46486d6acdbaf@syzkaller.appspotmail.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: <stable@kernel.org>
Cc: syzkaller-bugs <syzkaller-bugs@googlegroups.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

…ridge_leave()

This was not caught because there is no switch driver which implements
the .port_bridge_join but not .port_bridge_leave method, but it should
nonetheless be fixed, as in certain conditions (driver development) it
might lead to NULL pointer dereference.

Fixes: f66a6a6 ("net: dsa: permit cross-chip bridging between all trees in the system")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

…el/git/hansg/linux

Pull vboxsf fixes from Hans de Goede:
 "This adds support for the atomic_open directory-inode op to vboxsf.

  Note this is not just an enhancement this also fixes an actual issue
  which users are hitting, see the commit message of the "boxsf: Add
  support for the atomic_open directory-inode" patch"

* tag 'vboxsf-v5.14-1' of git://git.kernel.org/pub/scm/linux/kernel/git/hansg/linux:
  vboxsf: Add support for the atomic_open directory-inode op
  vboxsf: Add vboxsf_[create|release]_sf_handle() helpers
  vboxsf: Make vboxsf_dir_create() return the handle for the created file
  vboxsf: Honor excl flag to the dir-inode create op