linux-stable.git/net, branch v6.1.32

netfilter: ctnetlink: Support offloaded conntrack entry deletion

2023-06-05T07:26:22+00:00

commit 9b7c68b3911aef84afa4cbfc31bce20f10570d51 upstream.

Currently, offloaded conntrack entries (flows) can only be deleted
after they are removed from offload, which is either by timeout,
tcp state change or tc ct rule deletion. This can cause issues for
users wishing to manually delete or flush existing entries.

Support deletion of offloaded conntrack entries.

Example usage:
 # Delete all offloaded (and non offloaded) conntrack entries
 # whose source address is 1.2.3.4
 $ conntrack -D -s 1.2.3.4
 # Delete all entries
 $ conntrack -F

Signed-off-by: Paul Blakey 
Reviewed-by: Simon Horman 
Acked-by: Pablo Neira Ayuso 
Signed-off-by: Florian Westphal 
Cc: Demi Marie Obenour 
Signed-off-by: Greg Kroah-Hartman

bluetooth: Add cmd validity checks at the start of hci_sock_ioctl()

2023-06-05T07:26:21+00:00

commit 000c2fa2c144c499c881a101819cf1936a1f7cf2 upstream.

Previously, channel open messages were always sent to monitors on the first
ioctl() call for unbound HCI sockets, even if the command and arguments
were completely invalid. This can leave an exploitable hole with the abuse
of invalid ioctl calls.

This commit hardens the ioctl processing logic by first checking if the
command is valid, and immediately returning with an ENOIOCTLCMD error code
if it is not. This ensures that ioctl calls with invalid commands are free
of side effects, and increases the difficulty of further exploitation by
forcing exploitation to find a way to pass a valid command first.

Signed-off-by: Ruihan Li 
Co-developed-by: Marcel Holtmann 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Luiz Augusto von Dentz 
Signed-off-by: Dragos-Marian Panait 
Signed-off-by: Greg Kroah-Hartman

page_pool: fix inconsistency for page_pool_ring_[un]lock()

2023-06-05T07:26:20+00:00

[ Upstream commit 368d3cb406cdd074d1df2ad9ec06d1bfcb664882 ]

page_pool_ring_[un]lock() use in_softirq() to decide which
spin lock variant to use, and when they are called in the
context with in_softirq() being false, spin_lock_bh() is
called in page_pool_ring_lock() while spin_unlock() is
called in page_pool_ring_unlock(), because spin_lock_bh()
has disabled the softirq in page_pool_ring_lock(), which
causes inconsistency for spin lock pair calling.

This patch fixes it by returning in_softirq state from
page_pool_producer_lock(), and use it to decide which
spin lock variant to use in page_pool_producer_unlock().

As pool->ring has both producer and consumer lock, so
rename it to page_pool_producer_[un]lock() to reflect
the actual usage. Also move them to page_pool.c as they
are only used there, and remove the 'inline' as the
compiler may have better idea to do inlining or not.

Fixes: 7886244736a4 ("net: page_pool: Add bulk support for ptr_ring")
Signed-off-by: Yunsheng Lin 
Acked-by: Jesper Dangaard Brouer 
Acked-by: Ilias Apalodimas 
Link: https://lore.kernel.org/r/20230522031714.5089-1-linyunsheng@huawei.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

net: page_pool: use in_softirq() instead

2023-06-05T07:26:20+00:00

[ Upstream commit 542bcea4be866b14b3a5c8e90773329066656c43 ]

We use BH context only for synchronization, so we don't care if it's
actually serving softirq or not.

As a side node, in case of threaded NAPI, in_serving_softirq() will
return false because it's in process context with BH off, making
page_pool_recycle_in_cache() unreachable.

Signed-off-by: Qingfang DENG 
Tested-by: Felix Fietkau 
Signed-off-by: David S. Miller 
Stable-dep-of: 368d3cb406cd ("page_pool: fix inconsistency for page_pool_ring_[un]lock()")
Signed-off-by: Sasha Levin

bpf, sockmap: Incorrectly handling copied_seq

2023-06-05T07:26:19+00:00

[ Upstream commit e5c6de5fa025882babf89cecbed80acf49b987fa ]

The read_skb() logic is incrementing the tcp->copied_seq which is used for
among other things calculating how many outstanding bytes can be read by
the application. This results in application errors, if the application
does an ioctl(FIONREAD) we return zero because this is calculated from
the copied_seq value.

To fix this we move tcp->copied_seq accounting into the recv handler so
that we update these when the recvmsg() hook is called and data is in
fact copied into user buffers. This gives an accurate FIONREAD value
as expected and improves ACK handling. Before we were calling the
tcp_rcv_space_adjust() which would update 'number of bytes copied to
user in last RTT' which is wrong for programs returning SK_PASS. The
bytes are only copied to the user when recvmsg is handled.

Doing the fix for recvmsg is straightforward, but fixing redirect and
SK_DROP pkts is a bit tricker. Build a tcp_psock_eat() helper and then
call this from skmsg handlers. This fixes another issue where a broken
socket with a BPF program doing a resubmit could hang the receiver. This
happened because although read_skb() consumed the skb through sock_drop()
it did not update the copied_seq. Now if a single reccv socket is
redirecting to many sockets (for example for lb) the receiver sk will be
hung even though we might expect it to continue. The hang comes from
not updating the copied_seq numbers and memory pressure resulting from
that.

We have a slight layer problem of calling tcp_eat_skb even if its not
a TCP socket. To fix we could refactor and create per type receiver
handlers. I decided this is more work than we want in the fix and we
already have some small tweaks depending on caller that use the
helper skb_bpf_strparser(). So we extend that a bit and always set
the strparser bit when it is in use and then we can gate the
seq_copied updates on this.

Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20230523025618.113937-9-john.fastabend@gmail.com
Signed-off-by: Sasha Levin

bpf, sockmap: Wake up polling after data copy

2023-06-05T07:26:19+00:00

[ Upstream commit 6df7f764cd3cf5a03a4a47b23be47e57e41fcd85 ]

When TCP stack has data ready to read sk_data_ready() is called. Sockmap
overwrites this with its own handler to call into BPF verdict program.
But, the original TCP socket had sock_def_readable that would additionally
wake up any user space waiters with sk_wake_async().

Sockmap saved the callback when the socket was created so call the saved
data ready callback and then we can wake up any epoll() logic waiting
on the read.

Note we call on 'copied >= 0' to account for returning 0 when a FIN is
received because we need to wake up user for this as well so they
can do the recvmsg() -> 0 and detect the shutdown.

Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20230523025618.113937-8-john.fastabend@gmail.com
Signed-off-by: Sasha Levin

bpf, sockmap: TCP data stall on recv before accept

2023-06-05T07:26:19+00:00

[ Upstream commit ea444185a6bf7da4dd0df1598ee953e4f7174858 ]

A common mechanism to put a TCP socket into the sockmap is to hook the
BPF_SOCK_OPS_{ACTIVE_PASSIVE}_ESTABLISHED_CB event with a BPF program
that can map the socket info to the correct BPF verdict parser. When
the user adds the socket to the map the psock is created and the new
ops are assigned to ensure the verdict program will 'see' the sk_buffs
as they arrive.

Part of this process hooks the sk_data_ready op with a BPF specific
handler to wake up the BPF verdict program when data is ready to read.
The logic is simple enough (posted here for easy reading)

 static void sk_psock_verdict_data_ready(struct sock *sk)
 {
	struct socket *sock = sk->sk_socket;

	if (unlikely(!sock || !sock->ops || !sock->ops->read_skb))
		return;
	sock->ops->read_skb(sk, sk_psock_verdict_recv);
 }

The oversight here is sk->sk_socket is not assigned until the application
accepts() the new socket. However, its entirely ok for the peer application
to do a connect() followed immediately by sends. The socket on the receiver
is sitting on the backlog queue of the listening socket until its accepted
and the data is queued up. If the peer never accepts the socket or is slow
it will eventually hit data limits and rate limit the session. But,
important for BPF sockmap hooks when this data is received TCP stack does
the sk_data_ready() call but the read_skb() for this data is never called
because sk_socket is missing. The data sits on the sk_receive_queue.

Then once the socket is accepted if we never receive more data from the
peer there will be no further sk_data_ready calls and all the data
is still on the sk_receive_queue(). Then user calls recvmsg after accept()
and for TCP sockets in sockmap we use the tcp_bpf_recvmsg_parser() handler.
The handler checks for data in the sk_msg ingress queue expecting that
the BPF program has already run from the sk_data_ready hook and enqueued
the data as needed. So we are stuck.

To fix do an unlikely check in recvmsg handler for data on the
sk_receive_queue and if it exists wake up data_ready. We have the sock
locked in both read_skb and recvmsg so should avoid having multiple
runners.

Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20230523025618.113937-7-john.fastabend@gmail.com
Signed-off-by: Sasha Levin

bpf, sockmap: Handle fin correctly

2023-06-05T07:26:19+00:00

[ Upstream commit 901546fd8f9ca4b5c481ce00928ab425ce9aacc0 ]

The sockmap code is returning EAGAIN after a FIN packet is received and no
more data is on the receive queue. Correct behavior is to return 0 to the
user and the user can then close the socket. The EAGAIN causes many apps
to retry which masks the problem. Eventually the socket is evicted from
the sockmap because its released from sockmap sock free handling. The
issue creates a delay and can cause some errors on application side.

To fix this check on sk_msg_recvmsg side if length is zero and FIN flag
is set then set return to zero. A selftest will be added to check this
condition.

Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Tested-by: William Findlay 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20230523025618.113937-6-john.fastabend@gmail.com
Signed-off-by: Sasha Levin

bpf, sockmap: Improved check for empty queue

2023-06-05T07:26:19+00:00

[ Upstream commit 405df89dd52cbcd69a3cd7d9a10d64de38f854b2 ]

We noticed some rare sk_buffs were stepping past the queue when system was
under memory pressure. The general theory is to skip enqueueing
sk_buffs when its not necessary which is the normal case with a system
that is properly provisioned for the task, no memory pressure and enough
cpu assigned.

But, if we can't allocate memory due to an ENOMEM error when enqueueing
the sk_buff into the sockmap receive queue we push it onto a delayed
workqueue to retry later. When a new sk_buff is received we then check
if that queue is empty. However, there is a problem with simply checking
the queue length. When a sk_buff is being processed from the ingress queue
but not yet on the sockmap msg receive queue its possible to also recv
a sk_buff through normal path. It will check the ingress queue which is
zero and then skip ahead of the pkt being processed.

Previously we used sock lock from both contexts which made the problem
harder to hit, but not impossible.

To fix instead of popping the skb from the queue entirely we peek the
skb from the queue and do the copy there. This ensures checks to the
queue length are non-zero while skb is being processed. Then finally
when the entire skb has been copied to user space queue or another
socket we pop it off the queue. This way the queue length check allows
bypassing the queue only after the list has been completely processed.

To reproduce issue we run NGINX compliance test with sockmap running and
observe some flakes in our testing that we attributed to this issue.

Fixes: 04919bed948dc ("tcp: Introduce tcp_read_skb()")
Suggested-by: Jakub Sitnicki 
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Tested-by: William Findlay 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20230523025618.113937-5-john.fastabend@gmail.com
Signed-off-by: Sasha Levin

bpf, sockmap: Reschedule is now done through backlog

2023-06-05T07:26:18+00:00

[ Upstream commit bce22552f92ea7c577f49839b8e8f7d29afaf880 ]

Now that the backlog manages the reschedule() logic correctly we can drop
the partial fix to reschedule from recvmsg hook.

Rescheduling on recvmsg hook was added to address a corner case where we
still had data in the backlog state but had nothing to kick it and
reschedule the backlog worker to run and finish copying data out of the
state. This had a couple limitations, first it required user space to
kick it introducing an unnecessary EBUSY and retry. Second it only
handled the ingress case and egress redirects would still be hung.

With the correct fix, pushing the reschedule logic down to where the
enomem error occurs we can drop this fix.

Fixes: bec217197b412 ("skmsg: Schedule psock work if the cached skb exists on the psock")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/bpf/20230523025618.113937-4-john.fastabend@gmail.com
Signed-off-by: Sasha Levin