IRQs are disabled when freeing skbs in input queue.
Use the IRQ safe variant to free skbs here.

Fixes: 145dd5f9 ("net: flush the softnet backlog in process context")
Signed-off-by: NSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We have to detach sock from socket in qrtr_release(),
otherwise skb->sk may still reference to this socket
when the skb is released in tun->queue, particularly
sk->sk_wq still points to &sock->wq, which leads to
a UAF.

Reported-and-tested-by: syzbot+6720d64f31c081c2f708@syzkaller.appspotmail.com
Fixes: 28fb4e59 ("net: qrtr: Expose tunneling endpoint to user space")
Cc: Bjorn Andersson <bjorn.andersson@linaro.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NCong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_session_free called BUG_ON if the tunnel magic feather value wasn't
correct.  The intent of this was to catch lifetime bugs; for example
early tunnel free due to incorrect use of reference counts.

Since the tunnel magic feather being wrong indicates either early free
or structure corruption, we can avoid doing more damage by simply
leaving the tunnel structure alone.  If the tunnel refcount isn't
dropped when it should be, the tunnel instance will remain in the
kernel, resulting in the tunnel structure and socket leaking.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_session_free is only called by l2tp_session_dec_refcount when the
reference count reaches zero, so it's of limited value to validate the
reference count value in l2tp_session_free itself.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_session_queue_purge is used during session shutdown to drop any
skbs queued for reordering purposes according to L2TP dataplane rules.

The BUG_ON in this function checks the session magic feather in an
attempt to catch lifetime bugs.

Rather than crashing the kernel with a BUG_ON, we can simply WARN_ON and
refuse to do anything more -- in the worst case this could result in a
leak.  However this is highly unlikely given that the session purge only
occurs from codepaths which have obtained the session by means of a lookup
via. the parent tunnel and which check the session "dead" flag to
protect against shutdown races.

While we're here, have l2tp_session_queue_purge return void rather than
an integer, since neither of the callsites checked the return value.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

checkpatch advises that WARN_ON and recovery code are preferred over
BUG_ON which crashes the kernel.

l2tp_ppp has a BUG_ON check of struct seq_file's private pointer in
pppol2tp_seq_start prior to accessing data through that pointer.

Rather than crashing, we can simply bail out early and return NULL in
order to terminate the seq file processing in much the same way as we do
when reaching the end of tunnel/session instances to render.

Retain a WARN_ON to help trace possible bugs in this area.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

checkpatch advises that WARN_ON and recovery code are preferred over
BUG_ON which crashes the kernel.

l2tp_ppp.c's BUG_ON checks of the l2tp session structure's "magic" field
occur in code paths where it's reasonably easy to recover:

 * In the case of pppol2tp_sock_to_session, we can return NULL and the
   caller will bail out appropriately.  There is no change required to
   any of the callsites of this function since they already handle
   pppol2tp_sock_to_session returning NULL.

 * In the case of pppol2tp_session_destruct we can just avoid
   decrementing the reference count on the suspect session structure.
   In the worst case scenario this results in a memory leak, which is
   preferable to a crash.

Convert these uses of BUG_ON to WARN_ON accordingly.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_tunnel_closeall is only called from l2tp_core.c, and it's easy
to statically analyse the code path calling it to validate that it
should never be passed a NULL tunnel pointer.

Having a BUG_ON checking the tunnel pointer triggers a checkpatch
warning.  Since the BUG_ON is of no value, remove it to avoid the
warning.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_session_queue_purge is only called from l2tp_core.c, and it's easy
to statically analyse the code paths calling it to validate that it
should never be passed a NULL session pointer.

Having a BUG_ON checking the session pointer triggers a checkpatch
warning.  Since the BUG_ON is of no value, remove it to avoid the
warning.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

l2tp_dfs_seq_start had a BUG_ON to catch a possible programming error in
l2tp_dfs_seq_open.

Since we can easily bail out of l2tp_dfs_seq_start, prefer to do that
and flag the error with a WARN_ON rather than crashing the kernel.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

checkpatch warns about multiple assignments.

Update l2tp accordingly.
Signed-off-by: NTom Parkin <tparkin@katalix.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Extend the rfc 4884 read interface introduced for ipv4 in
commit eba75c58 ("icmp: support rfc 4884") to ipv6.

Add socket option SOL_IPV6/IPV6_RECVERR_RFC4884.

Changes v1->v2:
  - make ipv6_icmp_error_rfc4884 static (file scope)
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The RFC 4884 spec is largely the same between IPv4 and IPv6.
Factor out the IPv4 specific parts in preparation for IPv6 support:

- icmp types supported

- icmp header size, and thus offset to original datagram start

- datagram length field offset in icmp(6)hdr.

- datagram length field word size: 4B for IPv4, 8B for IPv6.
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

1) Only accept packets with original datagram len field >= header len.

The extension header must start after the original datagram headers.
The embedded datagram len field is compared against the 128B minimum
stipulated by RFC 4884. It is unlikely that headers extend beyond
this. But as we know the exact header length, check explicitly.

2) Remove the check that datagram length must be <= 576B.

This is a send constraint. There is no value in testing this on rx.
Within private networks it may be known safe to send larger packets.
Process these packets.

This test was also too lax. It compared original datagram length
rather than entire icmp packet length. The stand-alone fix would be:

  -       if (hlen + skb->len > 576)
  +       if (-skb_network_offset(skb) + skb->len > 576)

Fixes: eba75c58 ("icmp: support rfc 4884")
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The variable status is being initialized with a value that is never read
and it is being updated later with a new value.  The initialization is
redundant and can be removed.  Also put the variable declarations into
reverse christmas tree order.

Addresses-Coverity: ("Unused value")
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The previous patch introduced a deadlock, this patch fixes it by making
sure the work is canceled without holding the global ovs lock. This is
done by moving the reorder processing one layer up to the netns level.

Fixes: eac87c41 ("net: openvswitch: reorder masks array based on usage")
Reported-by: syzbot+2c4ff3614695f75ce26c@syzkaller.appspotmail.com
Reported-by: syzbot+bad6507e5db05017b008@syzkaller.appspotmail.com
Reviewed-by: NPaolo <pabeni@redhat.com>
Signed-off-by: NEelco Chaudron <echaudro@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This sockopt accepts two kinds of parameters, using struct
sctp_sack_info and struct sctp_assoc_value. The mentioned commit didn't
notice an implicit cast from the smaller (latter) struct to the bigger
one (former) when copying the data from the user space, which now leads
to an attempt to write beyond the buffer (because it assumes the storing
buffer is bigger than the parameter itself).

Fix it by allocating a sctp_sack_info on stack and filling it out based
on the small struct for the compat case.

Changelog stole from an earlier patch from Marcelo Ricardo Leitner.

Fixes: ebb25def ("sctp: pass a kernel pointer to sctp_setsockopt_delayed_ack")
Reported-by: syzbot+0e4699d000d8b874d8dc@syzkaller.appspotmail.com
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

For architectures like x86 and arm64 we don't need the separate bit to
indicate that a pointer is a kernel pointer as the address spaces are
unified.  That way the sockptr_t can be reduced to a union of two
pointers, which leads to nicer calling conventions.

The only caveat is that we need to check that users don't pass in kernel
address and thus gain access to kernel memory.  Thus the USER_SOCKPTR
helper is replaced with a init_user_sockptr function that does this check
and returns an error if it fails.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Rework the remaining setsockopt code to pass a sockptr_t instead of a
plain user pointer.  This removes the last remaining set_fs(KERNEL_DS)
outside of architecture specific code.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154]
Acked-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Factour out a helper to set the IPv6 option headers from
do_ipv6_setsockopt.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.

Note that the get case is pretty weird in that it actually copies data
back to userspace from setsockopt.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Split ipv6_flowlabel_opt into a subfunction for each action and a small
wrapper.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Use the sockptr_t type to merge the versions.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is mostly to prepare for cleaning up the callers, as bpfilter by
design can't handle kernel pointers.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NMatthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Pass a sockptr_t to prepare for set_fs-less handling of the kernel
pointer from bpf-cgroup.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The bpfilter user mode helper processes the optval address using
process_vm_readv.  Don't send it kernel addresses fed under
set_fs(KERNEL_DS) as that won't work.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>