This command:
$ tc qdisc replace dev eth0 ingress_block 1 egress_block 1 clsact
Error: block dev insert failed: -EBUSY.
fails because user space requests the same block index to be set for
both ingress and egress.
[ side note, I don't think it even failed prior to commit 913b47d342
("net/sched: Introduce tc block netdev tracking infra"), because this
is a command from an old set of notes of mine which used to work, but
alas, I did not scientifically bisect this ]
The problem is not that it fails, but rather, that the second time
around, it fails differently (and irrecoverably):
$ tc qdisc replace dev eth0 ingress_block 1 egress_block 1 clsact
Error: dsa_core: Flow block cb is busy.
[ another note: the extack is added by me for illustration purposes.
the context of the problem is that clsact_init() obtains the same
&q->ingress_block pointer as &q->egress_block, and since we call
tcf_block_get_ext() on both of them, "dev" will be added to the
block->ports xarray twice, thus failing the operation: once through
the ingress block pointer, and once again through the egress block
pointer. the problem itself is that when xa_insert() fails, we have
emitted a FLOW_BLOCK_BIND command through ndo_setup_tc(), but the
offload never sees a corresponding FLOW_BLOCK_UNBIND. ]
Even correcting the bad user input, we still cannot recover:
$ tc qdisc replace dev swp3 ingress_block 1 egress_block 2 clsact
Error: dsa_core: Flow block cb is busy.
Basically the only way to recover is to reboot the system, or unbind and
rebind the net device driver.
To fix the bug, we need to fill the correct error teardown path which
was missed during code movement, and call tcf_block_offload_unbind()
when xa_insert() fails.
[ last note, fundamentally I blame the label naming convention in
tcf_block_get_ext() for the bug. The labels should be named after what
they do, not after the error path that jumps to them. This way, it is
obviously wrong that two labels pointing to the same code mean
something is wrong, and checking the code correctness at the goto site
is also easier ]
Fixes: 94e2557d08 ("net: sched: move block device tracking into tcf_block_get/put_ext()")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20241023100541.974362-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In qdisc_tree_reduce_backlog, Qdiscs with major handle ffff: are assumed
to be either root or ingress. This assumption is bogus since it's valid
to create egress qdiscs with major handle ffff:
Budimir Markovic found that for qdiscs like DRR that maintain an active
class list, it will cause a UAF with a dangling class pointer.
In 066a3b5b23, the concern was to avoid iterating over the ingress
qdisc since its parent is itself. The proper fix is to stop when parent
TC_H_ROOT is reached because the only way to retrieve ingress is when a
hierarchy which does not contain a ffff: major handle call into
qdisc_lookup with TC_H_MAJ(TC_H_ROOT).
In the scenario where major ffff: is an egress qdisc in any of the tree
levels, the updates will also propagate to TC_H_ROOT, which then the
iteration must stop.
Fixes: 066a3b5b23 ("[NET_SCHED] sch_api: fix qdisc_tree_decrease_qlen() loop")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Suggested-by: Jamal Hadi Salim <jhs@mojatatu.com>
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Pedro Tammela <pctammela@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
net/sched/sch_api.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20241024165547.418570-1-jhs@mojatatu.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In 'taprio_change()', 'admin' pointer may become dangling due to sched
switch / removal caused by 'advance_sched()', and critical section
protected by 'q->current_entry_lock' is too small to prevent from such
a scenario (which causes use-after-free detected by KASAN). Fix this
by prefer 'rcu_replace_pointer()' over 'rcu_assign_pointer()' to update
'admin' immediately before an attempt to schedule freeing.
Fixes: a3d43c0d56 ("taprio: Add support adding an admin schedule")
Reported-by: syzbot+b65e0af58423fc8a73aa@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Link: https://patch.msgid.link/20241018051339.418890-1-dmantipov@yandex.ru
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
tcf_action_init() has logic for checking mismatches between action and
filter offload flags (skip_sw/skip_hw). AFAIU, this is intended to run
on the transition between the new tc_act_bind(flags) returning true (aka
now gets bound to classifier) and tc_act_bind(act->tcfa_flags) returning
false (aka action was not bound to classifier before). Otherwise, the
check is skipped.
For the case where an action is not standalone, but rather it was
created by a classifier and is bound to it, tcf_action_init() skips the
check entirely, and this means it allows mismatched flags to occur.
Taking the matchall classifier code path as an example (with mirred as
an action), the reason is the following:
1 | mall_change()
2 | -> mall_replace_hw_filter()
3 | -> tcf_exts_validate_ex()
4 | -> flags |= TCA_ACT_FLAGS_BIND;
5 | -> tcf_action_init()
6 | -> tcf_action_init_1()
7 | -> a_o->init()
8 | -> tcf_mirred_init()
9 | -> tcf_idr_create_from_flags()
10 | -> tcf_idr_create()
11 | -> p->tcfa_flags = flags;
12 | -> tc_act_bind(flags))
13 | -> tc_act_bind(act->tcfa_flags)
When invoked from tcf_exts_validate_ex() like matchall does (but other
classifiers validate their extensions as well), tcf_action_init() runs
in a call path where "flags" always contains TCA_ACT_FLAGS_BIND (set by
line 4). So line 12 is always true, and line 13 is always true as well.
No transition ever takes place, and the check is skipped.
The code was added in this form in commit c86e0209dc ("flow_offload:
validate flags of filter and actions"), but I'm attributing the blame
even earlier in that series, to when TCA_ACT_FLAGS_SKIP_HW and
TCA_ACT_FLAGS_SKIP_SW were added to the UAPI.
Following the development process of this change, the check did not
always exist in this form. A change took place between v3 [1] and v4 [2],
AFAIU due to review feedback that it doesn't make sense for action flags
to be different than classifier flags. I think I agree with that
feedback, but it was translated into code that omits enforcing this for
"classic" actions created at the same time with the filters themselves.
There are 3 more important cases to discuss. First there is this command:
$ tc qdisc add dev eth0 clasct
$ tc filter add dev eth0 ingress matchall skip_sw \
action mirred ingress mirror dev eth1
which should be allowed, because prior to the concept of dedicated
action flags, it used to work and it used to mean the action inherited
the skip_sw/skip_hw flags from the classifier. It's not a mismatch.
Then we have this command:
$ tc qdisc add dev eth0 clasct
$ tc filter add dev eth0 ingress matchall skip_sw \
action mirred ingress mirror dev eth1 skip_hw
where there is a mismatch and it should be rejected.
Finally, we have:
$ tc qdisc add dev eth0 clasct
$ tc filter add dev eth0 ingress matchall skip_sw \
action mirred ingress mirror dev eth1 skip_sw
where the offload flags coincide, and this should be treated the same as
the first command based on inheritance, and accepted.
[1]: https://lore.kernel.org/netdev/20211028110646.13791-9-simon.horman@corigine.com/
[2]: https://lore.kernel.org/netdev/20211118130805.23897-10-simon.horman@corigine.com/
Fixes: 7adc576512 ("flow_offload: add skip_hw and skip_sw to control if offload the action")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20241017161049.3570037-1-vladimir.oltean@nxp.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Some workloads hit the infamous dev_watchdog() message:
"NETDEV WATCHDOG: eth0 (xxxx): transmit queue XX timed out"
It seems possible to hit this even for perfectly normal
BQL enabled drivers:
1) Assume a TX queue was idle for more than dev->watchdog_timeo
(5 seconds unless changed by the driver)
2) Assume a big packet is sent, exceeding current BQL limit.
3) Driver ndo_start_xmit() puts the packet in TX ring,
and netdev_tx_sent_queue() is called.
4) QUEUE_STATE_STACK_XOFF could be set from netdev_tx_sent_queue()
before txq->trans_start has been written.
5) txq->trans_start is written later, from netdev_start_xmit()
if (rc == NETDEV_TX_OK)
txq_trans_update(txq)
dev_watchdog() running on another cpu could read the old
txq->trans_start, and then see QUEUE_STATE_STACK_XOFF, because 5)
did not happen yet.
To solve the issue, write txq->trans_start right before one XOFF bit
is set :
- _QUEUE_STATE_DRV_XOFF from netif_tx_stop_queue()
- __QUEUE_STATE_STACK_XOFF from netdev_tx_sent_queue()
From dev_watchdog(), we have to read txq->state before txq->trans_start.
Add memory barriers to enforce correct ordering.
In the future, we could avoid writing over txq->trans_start for normal
operations, and rename this field to txq->xoff_start_time.
Fixes: bec251bc8b ("net: no longer stop all TX queues in dev_watchdog()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20241015194118.3951657-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
sch_cake uses a cache of the first 16 values of the inverse square root
calculation for the Cobalt AQM to save some cycles on the fast path.
This cache is populated when the qdisc is first loaded, but there's
really no reason why it can't just be pre-populated. So change it to be
pre-populated with constants, which also makes it possible to constify
it.
This gives a modest space saving for the module (not counting debug data):
.text: -224 bytes
.rodata: +80 bytes
.bss: -64 bytes
Total: -192 bytes
Signed-off-by: Dave Taht <dave.taht@gmail.com>
[ fixed up comment, rewrote commit message ]
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20240909091630.22177-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
According to Vinicius (and carefully looking through the whole
https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa
once again), txtime branch of 'taprio_change()' is not going to
race against 'advance_sched()'. But using 'rcu_replace_pointer()'
in the former may be a good idea as well.
Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In sch_cake, we keep track of the count of active bulk flows per host,
when running in dst/src host fairness mode, which is used as the
round-robin weight when iterating through flows. The count of active
bulk flows is updated whenever a flow changes state.
This has a peculiar interaction with the hash collision handling: when a
hash collision occurs (after the set-associative hashing), the state of
the hash bucket is simply updated to match the new packet that collided,
and if host fairness is enabled, that also means assigning new per-host
state to the flow. For this reason, the bulk flow counters of the
host(s) assigned to the flow are decremented, before new state is
assigned (and the counters, which may not belong to the same host
anymore, are incremented again).
Back when this code was introduced, the host fairness mode was always
enabled, so the decrement was unconditional. When the configuration
flags were introduced the *increment* was made conditional, but
the *decrement* was not. Which of course can lead to a spurious
decrement (and associated wrap-around to U16_MAX).
AFAICT, when host fairness is disabled, the decrement and wrap-around
happens as soon as a hash collision occurs (which is not that common in
itself, due to the set-associative hashing). However, in most cases this
is harmless, as the value is only used when host fairness mode is
enabled. So in order to trigger an array overflow, sch_cake has to first
be configured with host fairness disabled, and while running in this
mode, a hash collision has to occur to cause the overflow. Then, the
qdisc has to be reconfigured to enable host fairness, which leads to the
array out-of-bounds because the wrapped-around value is retained and
used as an array index. It seems that syzbot managed to trigger this,
which is quite impressive in its own right.
This patch fixes the issue by introducing the same conditional check on
decrement as is used on increment.
The original bug predates the upstreaming of cake, but the commit listed
in the Fixes tag touched that code, meaning that this patch won't apply
before that.
Fixes: 7126399299 ("sch_cake: Make the dual modes fairer")
Reported-by: syzbot+7fe7b81d602cc1e6b94d@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20240903160846.20909-1-toke@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
If netem_dequeue() enqueues packet to inner qdisc and that qdisc
returns __NET_XMIT_STOLEN. The packet is dropped but
qdisc_tree_reduce_backlog() is not called to update the parent's
q.qlen, leading to the similar use-after-free as Commit
e04991a48dbaf382 ("netem: fix return value if duplicate enqueue
fails")
Commands to trigger KASAN UaF:
ip link add type dummy
ip link set lo up
ip link set dummy0 up
tc qdisc add dev lo parent root handle 1: drr
tc filter add dev lo parent 1: basic classid 1:1
tc class add dev lo classid 1:1 drr
tc qdisc add dev lo parent 1:1 handle 2: netem
tc qdisc add dev lo parent 2: handle 3: drr
tc filter add dev lo parent 3: basic classid 3:1 action mirred egress
redirect dev dummy0
tc class add dev lo classid 3:1 drr
ping -c1 -W0.01 localhost # Trigger bug
tc class del dev lo classid 1:1
tc class add dev lo classid 1:1 drr
ping -c1 -W0.01 localhost # UaF
Fixes: 50612537e9 ("netem: fix classful handling")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Link: https://patch.msgid.link/20240901182438.4992-1-stephen@networkplumber.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
fq_dequeue() has a complex logic to find packets in one of the 3 bands.
As Neal found out, it is possible that one band has a deficit smaller
than its weight. fq_dequeue() can return NULL while some packets are
elligible for immediate transmit.
In this case, more than one iteration is needed to refill pband->credit.
With default parameters (weights 589824 196608 65536) bug can trigger
if large BIG TCP packets are sent to the lowest priority band.
Bisected-by: John Sperbeck <jsperbeck@google.com>
Diagnosed-by: Neal Cardwell <ncardwell@google.com>
Fixes: 29f834aa32 ("net_sched: sch_fq: add 3 bands and WRR scheduling")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20240824181901.953776-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
<tldr>
skb network header of the single-tagged vlan packet continues to point the
vlan payload (e.g. IP) after second vlan tag is pushed by tc act_vlan. This
causes problem at the dissector which expects double-tagged packet network
header to point to the inner vlan.
The fix is to adjust network header in tcf_act_vlan.c but requires
refactoring of skb_vlan_push function.
</tldr>
Consider the following shell script snippet configuring TC rules on the
veth interface:
ip link add veth0 type veth peer veth1
ip link set veth0 up
ip link set veth1 up
tc qdisc add dev veth0 clsact
tc filter add dev veth0 ingress pref 10 chain 0 flower \
num_of_vlans 2 cvlan_ethtype 0x800 action goto chain 5
tc filter add dev veth0 ingress pref 20 chain 0 flower \
num_of_vlans 1 action vlan push id 100 \
protocol 0x8100 action goto chain 5
tc filter add dev veth0 ingress pref 30 chain 5 flower \
num_of_vlans 2 cvlan_ethtype 0x800 action simple sdata "success"
Sending double-tagged vlan packet with the IP payload inside:
cat <<ENDS | text2pcap - - | tcpreplay -i veth1 -
0000 00 00 00 00 00 11 00 00 00 00 00 22 81 00 00 64 ..........."...d
0010 81 00 00 14 08 00 45 04 00 26 04 d2 00 00 7f 11 ......E..&......
0020 18 ef 0a 00 00 01 14 00 00 02 00 00 00 00 00 12 ................
0030 e1 c7 00 00 00 00 00 00 00 00 00 00 ............
ENDS
will match rule 10, goto rule 30 in chain 5 and correctly emit "success" to
the dmesg.
OTOH, sending single-tagged vlan packet:
cat <<ENDS | text2pcap - - | tcpreplay -i veth1 -
0000 00 00 00 00 00 11 00 00 00 00 00 22 81 00 00 14 ..........."....
0010 08 00 45 04 00 2a 04 d2 00 00 7f 11 18 eb 0a 00 ..E..*..........
0020 00 01 14 00 00 02 00 00 00 00 00 16 e1 bf 00 00 ................
0030 00 00 00 00 00 00 00 00 00 00 00 00 ............
ENDS
will match rule 20, will push the second vlan tag but will *not* match
rule 30. IOW, the match at rule 30 fails if the second vlan was freshly
pushed by the kernel.
Lets look at __skb_flow_dissect working on the double-tagged vlan packet.
Here is the relevant code from around net/core/flow_dissector.c:1277
copy-pasted here for convenience:
if (dissector_vlan == FLOW_DISSECTOR_KEY_MAX &&
skb && skb_vlan_tag_present(skb)) {
proto = skb->protocol;
} else {
vlan = __skb_header_pointer(skb, nhoff, sizeof(_vlan),
data, hlen, &_vlan);
if (!vlan) {
fdret = FLOW_DISSECT_RET_OUT_BAD;
break;
}
proto = vlan->h_vlan_encapsulated_proto;
nhoff += sizeof(*vlan);
}
The "else" clause above gets the protocol of the encapsulated packet from
the skb data at the network header location. printk debugging has showed
that in the good double-tagged packet case proto is
htons(0x800 == ETH_P_IP) as expected. However in the single-tagged packet
case proto is garbage leading to the failure to match tc filter 30.
proto is being set from the skb header pointed by nhoff parameter which is
defined at the beginning of __skb_flow_dissect
(net/core/flow_dissector.c:1055 in the current version):
nhoff = skb_network_offset(skb);
Therefore the culprit seems to be that the skb network offset is different
between double-tagged packet received from the interface and single-tagged
packet having its vlan tag pushed by TC.
Lets look at the interesting points of the lifetime of the single/double
tagged packets as they traverse our packet flow.
Both of them will start at __netif_receive_skb_core where the first vlan
tag will be stripped:
if (eth_type_vlan(skb->protocol)) {
skb = skb_vlan_untag(skb);
if (unlikely(!skb))
goto out;
}
At this stage in double-tagged case skb->data points to the second vlan tag
while in single-tagged case skb->data points to the network (eg. IP)
header.
Looking at TC vlan push action (net/sched/act_vlan.c) we have the following
code at tcf_vlan_act (interesting points are in square brackets):
if (skb_at_tc_ingress(skb))
[1] skb_push_rcsum(skb, skb->mac_len);
....
case TCA_VLAN_ACT_PUSH:
err = skb_vlan_push(skb, p->tcfv_push_proto, p->tcfv_push_vid |
(p->tcfv_push_prio << VLAN_PRIO_SHIFT),
0);
if (err)
goto drop;
break;
....
out:
if (skb_at_tc_ingress(skb))
[3] skb_pull_rcsum(skb, skb->mac_len);
And skb_vlan_push (net/core/skbuff.c:6204) function does:
err = __vlan_insert_tag(skb, skb->vlan_proto,
skb_vlan_tag_get(skb));
if (err)
return err;
skb->protocol = skb->vlan_proto;
[2] skb->mac_len += VLAN_HLEN;
in the case of pushing the second tag. Lets look at what happens with
skb->data of the single-tagged packet at each of the above points:
1. As a result of the skb_push_rcsum, skb->data is moved back to the start
of the packet.
2. First VLAN tag is moved from the skb into packet buffer, skb->mac_len is
incremented, skb->data still points to the start of the packet.
3. As a result of the skb_pull_rcsum, skb->data is moved forward by the
modified skb->mac_len, thus pointing to the network header again.
Then __skb_flow_dissect will get confused by having double-tagged vlan
packet with the skb->data at the network header.
The solution for the bug is to preserve "skb->data at second vlan header"
semantics in the skb_vlan_push function. We do this by manipulating
skb->network_header rather than skb->mac_len. skb_vlan_push callers are
updated to do skb_reset_mac_len.
Signed-off-by: Boris Sukholitko <boris.sukholitko@broadcom.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/broadcom/bnxt/bnxt.h
c948c0973d ("bnxt_en: Don't clear ntuple filters and rss contexts during ethtool ops")
f2878cdeb7 ("bnxt_en: Add support to call FW to update a VNIC")
Link: https://patch.msgid.link/20240822210125.1542769-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is a bug in netem_enqueue() introduced by
commit 5845f70638 ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
that can lead to a use-after-free.
This commit made netem_enqueue() always return NET_XMIT_SUCCESS
when a packet is duplicated, which can cause the parent qdisc's q.qlen
to be mistakenly incremented. When this happens qlen_notify() may be
skipped on the parent during destruction, leaving a dangling pointer
for some classful qdiscs like DRR.
There are two ways for the bug happen:
- If the duplicated packet is dropped by rootq->enqueue() and then
the original packet is also dropped.
- If rootq->enqueue() sends the duplicated packet to a different qdisc
and the original packet is dropped.
In both cases NET_XMIT_SUCCESS is returned even though no packets
are enqueued at the netem qdisc.
The fix is to defer the enqueue of the duplicate packet until after
the original packet has been guaranteed to return NET_XMIT_SUCCESS.
Fixes: 5845f70638 ("net: netem: fix skb length BUG_ON in __skb_to_sgvec")
Reported-by: Budimir Markovic <markovicbudimir@gmail.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240819175753.5151-1-stephen@networkplumber.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are
getting ready to enable it, globally.
Remove unnecessary flex-array member `pad[]` and refactor the related
code a bit.
Fix the following warning:
net/sched/act_ct.c:57:29: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://patch.msgid.link/ZrY0JMVsImbDbx6r@cute
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Make sure to set encapsulated control flags also for non-IP
packets, such that it's possible to allow matching on e.g.
TUNNEL_OAM on a geneve packet carrying a non-IP packet.
Suggested-by: Davide Caratti <dcaratti@redhat.com>
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-13-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now that TCA_FLOWER_KEY_ENC_FLAGS is unused, as it's
former data is stored behind TCA_FLOWER_KEY_ENC_CONTROL,
then remove the last bits of FLOW_DISSECTOR_KEY_ENC_FLAGS.
FLOW_DISSECTOR_KEY_ENC_FLAGS is unreleased, and have been
in net-next since 2024-06-04.
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-12-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch changes how TCA_FLOWER_KEY_ENC_FLAGS is used, so that
it is used with TCA_FLOWER_KEY_FLAGS_* flags, in the same way as
TCA_FLOWER_KEY_FLAGS is currently used.
Where TCA_FLOWER_KEY_FLAGS uses {key,mask}->control.flags, then
TCA_FLOWER_KEY_ENC_FLAGS now uses {key,mask}->enc_control.flags,
therefore {key,mask}->enc_flags is now unused.
As the generic fl_set_key_flags/fl_dump_key_flags() is used with
encap set to true, then fl_{set,dump}_key_enc_flags() is removed.
This breaks unreleased userspace API (net-next since 2024-06-04).
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-10-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Prepare to set and dump the tunnel flags.
This code won't see any of these flags yet, as these flags
aren't allowed by the NLA_POLICY_MASK, and the functions
doesn't get called with encap set to true yet.
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-9-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This policy guards fl_set_key_flags() from seeing flags
not used in the context of TCA_FLOWER_KEY_FLAGS.
In order For the policy check to be performed with the
correct endianness, then we also needs to change the
attribute type to NLA_BE32 (Thanks Davide).
TCA_FLOWER_KEY_FLAGS{,_MASK} already has a be32 comment
in include/uapi/linux/pkt_cls.h.
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-6-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Prepare fl_set_key_flags/fl_dump_key_flags() for use with
TCA_FLOWER_KEY_ENC_FLAGS{,_MASK}.
This patch adds an encap argument, similar to fl_set_key_ip/
fl_dump_key_ip(), and determine the flower keys based on the
encap argument, and use them in the rest of the two functions.
Since these functions are so far, only called with encap set false,
then there is no functional change.
Signed-off-by: Asbjørn Sloth Tønnesen <ast@fiberby.net>
Tested-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20240713021911.1631517-5-ast@fiberby.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In prevision to add new UAPI for hwtstamp we will be limited to the struct
ethtool_ts_info that is currently passed in fixed binary format through the
ETHTOOL_GET_TS_INFO ethtool ioctl. It would be good if new kernel code
already started operating on an extensible kernel variant of that
structure, similar in concept to struct kernel_hwtstamp_config vs struct
hwtstamp_config.
Since struct ethtool_ts_info is in include/uapi/linux/ethtool.h, here
we introduce the kernel-only structure in include/linux/ethtool.h.
The manual copy is then made in the function called by ETHTOOL_GET_TS_INFO.
Acked-by: Shannon Nelson <shannon.nelson@amd.com>
Acked-by: Alexandra Winter <wintera@linux.ibm.com>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Link: https://patch.msgid.link/20240709-feature_ptp_netnext-v17-6-b5317f50df2a@bootlin.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Replace a comma between expression statements by a semicolon.
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240709072838.1152880-1-nichen@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
Conflicts:
net/sched/act_ct.c
26488172b0 ("net/sched: Fix UAF when resolving a clash")
3abbd7ed8b ("act_ct: prepare for stolen verdict coming from conntrack and nat engine")
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pedro Pinto and later independently also Hyunwoo Kim and Wongi Lee reported
an issue that the tcx_entry can be released too early leading to a use
after free (UAF) when an active old-style ingress or clsact qdisc with a
shared tc block is later replaced by another ingress or clsact instance.
Essentially, the sequence to trigger the UAF (one example) can be as follows:
1. A network namespace is created
2. An ingress qdisc is created. This allocates a tcx_entry, and
&tcx_entry->miniq is stored in the qdisc's miniqp->p_miniq. At the
same time, a tcf block with index 1 is created.
3. chain0 is attached to the tcf block. chain0 must be connected to
the block linked to the ingress qdisc to later reach the function
tcf_chain0_head_change_cb_del() which triggers the UAF.
4. Create and graft a clsact qdisc. This causes the ingress qdisc
created in step 1 to be removed, thus freeing the previously linked
tcx_entry:
rtnetlink_rcv_msg()
=> tc_modify_qdisc()
=> qdisc_create()
=> clsact_init() [a]
=> qdisc_graft()
=> qdisc_destroy()
=> __qdisc_destroy()
=> ingress_destroy() [b]
=> tcx_entry_free()
=> kfree_rcu() // tcx_entry freed
5. Finally, the network namespace is closed. This registers the
cleanup_net worker, and during the process of releasing the
remaining clsact qdisc, it accesses the tcx_entry that was
already freed in step 4, causing the UAF to occur:
cleanup_net()
=> ops_exit_list()
=> default_device_exit_batch()
=> unregister_netdevice_many()
=> unregister_netdevice_many_notify()
=> dev_shutdown()
=> qdisc_put()
=> clsact_destroy() [c]
=> tcf_block_put_ext()
=> tcf_chain0_head_change_cb_del()
=> tcf_chain_head_change_item()
=> clsact_chain_head_change()
=> mini_qdisc_pair_swap() // UAF
There are also other variants, the gist is to add an ingress (or clsact)
qdisc with a specific shared block, then to replace that qdisc, waiting
for the tcx_entry kfree_rcu() to be executed and subsequently accessing
the current active qdisc's miniq one way or another.
The correct fix is to turn the miniq_active boolean into a counter. What
can be observed, at step 2 above, the counter transitions from 0->1, at
step [a] from 1->2 (in order for the miniq object to remain active during
the replacement), then in [b] from 2->1 and finally [c] 1->0 with the
eventual release. The reference counter in general ranges from [0,2] and
it does not need to be atomic since all access to the counter is protected
by the rtnl mutex. With this in place, there is no longer a UAF happening
and the tcx_entry is freed at the correct time.
Fixes: e420bed025 ("bpf: Add fd-based tcx multi-prog infra with link support")
Reported-by: Pedro Pinto <xten@osec.io>
Co-developed-by: Pedro Pinto <xten@osec.io>
Signed-off-by: Pedro Pinto <xten@osec.io>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Hyunwoo Kim <v4bel@theori.io>
Cc: Wongi Lee <qwerty@theori.io>
Cc: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240708133130.11609-1-daniel@iogearbox.net
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
At this time, conntrack either returns NF_ACCEPT or NF_DROP.
To improve debuging it would be nice to be able to replace NF_DROP verdict
with NF_DROP_REASON() helper,
This helper releases the skb instantly (so drop_monitor can pinpoint
exact location) and returns NF_STOLEN.
Prepare call sites to deal with this before introducing such changes
in conntrack and nat core.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
If the action has a user_cookie, pass it along to the sample so it can
be easily identified.
Reviewed-by: Michal Kubiak <michal.kubiak@intel.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Link: https://patch.msgid.link/20240704085710.353845-3-amorenoz@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/ethernet/broadcom/bnxt/bnxt.c
1e7962114c ("bnxt_en: Restore PTP tx_avail count in case of skb_pad() error")
165f87691a ("bnxt_en: add timestamping statistics support")
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
zones_ht is a global hashtable for flow_table with zone as key. However,
it does not consider netns when getting a flow_table from zones_ht in
tcf_ct_init(), and it means an act_ct action in netns A may get a
flow_table that belongs to netns B if it has the same zone value.
In Shuang's test with the TOPO:
tcf2_c <---> tcf2_sw1 <---> tcf2_sw2 <---> tcf2_s
tcf2_sw1 and tcf2_sw2 saw the same flow and used the same flow table,
which caused their ct entries entering unexpected states and the
TCP connection not able to end normally.
This patch fixes the issue simply by adding netns into the key of
tcf_ct_flow_table so that an act_ct action gets a flow_table that
belongs to its own netns in tcf_ct_init().
Note that for easy coding we don't use tcf_ct_flow_table.nf_ft.net,
as the ct_ft is initialized after inserting it to the hashtable in
tcf_ct_flow_table_get() and also it requires to implement several
functions in rhashtable_params including hashfn, obj_hashfn and
obj_cmpfn.
Fixes: 64ff70b80f ("net/sched: act_ct: Offload established connections to flow table")
Reported-by: Shuang Li <shuali@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://lore.kernel.org/r/1db5b6cc6902c5fc6f8c6cbd85494a2008087be5.1718488050.git.lucien.xin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
syzbot found hanging tasks waiting on rtnl_lock [1]
A reproducer is available in the syzbot bug.
When a request to add multiple actions with the same index is sent, the
second request will block forever on the first request. This holds
rtnl_lock, and causes tasks to hang.
Return -EAGAIN to prevent infinite looping, while keeping documented
behavior.
[1]
INFO: task kworker/1:0:5088 blocked for more than 143 seconds.
Not tainted 6.9.0-rc4-syzkaller-00173-g3cdb45594619 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:kworker/1:0 state:D stack:23744 pid:5088 tgid:5088 ppid:2 flags:0x00004000
Workqueue: events_power_efficient reg_check_chans_work
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5409 [inline]
__schedule+0xf15/0x5d00 kernel/sched/core.c:6746
__schedule_loop kernel/sched/core.c:6823 [inline]
schedule+0xe7/0x350 kernel/sched/core.c:6838
schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6895
__mutex_lock_common kernel/locking/mutex.c:684 [inline]
__mutex_lock+0x5b8/0x9c0 kernel/locking/mutex.c:752
wiphy_lock include/net/cfg80211.h:5953 [inline]
reg_leave_invalid_chans net/wireless/reg.c:2466 [inline]
reg_check_chans_work+0x10a/0x10e0 net/wireless/reg.c:2481
Fixes: 0190c1d452 ("net: sched: atomically check-allocate action")
Reported-by: syzbot+b87c222546179f4513a7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b87c222546179f4513a7
Signed-off-by: David Ruth <druth@chromium.org>
Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://lore.kernel.org/r/20240614190326.1349786-1-druth@chromium.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When the noop_qdisc owner isn't initialized, then it will be 0,
so packets will erroneously be regarded as having been subject
to recursion as long as only CPU 0 queues them. For non-SMP,
that's all packets, of course. This causes a change in what's
reported to userspace, normally noop_qdisc would drop packets
silently, but with this change the syscall returns -ENOBUFS if
RECVERR is also set on the socket.
Fix this by initializing the owner field to -1, just like it
would be for dynamically allocated qdiscs by qdisc_alloc().
Fixes: 0f022d32c3 ("net/sched: Fix mirred deadlock on device recursion")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240607175340.786bfb938803.I493bf8422e36be4454c08880a8d3703cea8e421a@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/pensando/ionic/ionic_txrx.c
d9c0420999 ("ionic: Mark error paths in the data path as unlikely")
491aee894a ("ionic: fix kernel panic in XDP_TX action")
net/ipv6/ip6_fib.c
b4cb4a1391 ("net: use unrcu_pointer() helper")
b01e1c0307 ("ipv6: fix possible race in __fib6_drop_pcpu_from()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Toke mentioned unrcu_pointer() existence, allowing
to remove some of the ugly casts we have when using
xchg() for rcu protected pointers.
Also make inet_rcv_compat const.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20240604111603.45871-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
If one TCA_TAPRIO_ATTR_PRIOMAP attribute has been provided,
taprio_parse_mqprio_opt() must validate it, or userspace
can inject arbitrary data to the kernel, the second time
taprio_change() is called.
First call (with valid attributes) sets dev->num_tc
to a non zero value.
Second call (with arbitrary mqprio attributes)
returns early from taprio_parse_mqprio_opt()
and bad things can happen.
Fixes: a3d43c0d56 ("taprio: Add support adding an admin schedule")
Reported-by: Noam Rathaus <noamr@ssd-disclosure.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240604181511.769870-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
q->bands will be assigned to qopt->bands to execute subsequent code logic
after kmalloc. So the old q->bands should not be used in kmalloc.
Otherwise, an out-of-bounds write will occur.
Fixes: c2999f7fb0 ("net: sched: multiq: don't call qdisc_put() while holding tree lock")
Signed-off-by: Hangyu Hua <hbh25y@gmail.com>
Acked-by: Cong Wang <cong.wang@bytedance.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
extend cls_flower to match TUNNEL_FLAGS_PRESENT bits in tunnel metadata.
Suggested-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Catching and debugging missing qdiscs is pretty tricky. When qdisc
is deleted we replace it with a noop qdisc, which silently drops
all the packets. Since the noop qdisc has a single static instance
we can't count drops at the qdisc level. Count them as dev->tx_drops.
ip netns add red
ip link add type veth peer netns red
ip link set dev veth0 up
ip -netns red link set dev veth0 up
ip a a dev veth0 10.0.0.1/24
ip -netns red a a dev veth0 10.0.0.2/24
ping -c 2 10.0.0.2
# 2 packets transmitted, 2 received, 0% packet loss, time 1031ms
ip -s link show dev veth0
# TX: bytes packets errors dropped carrier collsns
# 1314 17 0 0 0 0
tc qdisc replace dev veth0 root handle 1234: mq
tc qdisc replace dev veth0 parent 1234:1 pfifo
tc qdisc del dev veth0 parent 1234:1
ping -c 2 10.0.0.2
# 2 packets transmitted, 0 received, 100% packet loss, time 1034ms
ip -s link show dev veth0
# TX: bytes packets errors dropped carrier collsns
# 1314 17 0 3 0 0
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20240529162527.3688979-1-kuba@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/ethernet/ti/icssg/icssg_classifier.c
abd5576b9c ("net: ti: icssg-prueth: Add support for ICSSG switch firmware")
56a5cf538c ("net: ti: icssg-prueth: Fix start counter for ft1 filter")
https://lore.kernel.org/all/20240531123822.3bb7eadf@canb.auug.org.au/
No other adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
It is possible for syzbot to side-step the restriction imposed by the
blamed commit in the Fixes: tag, because the taprio UAPI permits a
cycle-time different from (and potentially shorter than) the sum of
entry intervals.
We need one more restriction, which is that the cycle time itself must
be larger than N * ETH_ZLEN bit times, where N is the number of schedule
entries. This restriction needs to apply regardless of whether the cycle
time came from the user or was the implicit, auto-calculated value, so
we move the existing "cycle == 0" check outside the "if "(!new->cycle_time)"
branch. This way covers both conditions and scenarios.
Add a selftest which illustrates the issue triggered by syzbot.
Fixes: b5b73b26b3 ("taprio: Fix allowing too small intervals")
Reported-by: syzbot+a7d2b1d5d1af83035567@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/0000000000007d66bc06196e7c66@google.com/
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20240527153955.553333-2-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In commit b5b73b26b3 ("taprio: Fix allowing too small intervals"), a
comparison of user input against length_to_duration(q, ETH_ZLEN) was
introduced, to avoid RCU stalls due to frequent hrtimers.
The implementation of length_to_duration() depends on q->picos_per_byte
being set for the link speed. The blamed commit in the Fixes: tag has
moved this too late, so the checks introduced above are ineffective.
The q->picos_per_byte is zero at parse_taprio_schedule() ->
parse_sched_list() -> parse_sched_entry() -> fill_sched_entry() time.
Move the taprio_set_picos_per_byte() call as one of the first things in
taprio_change(), before the bulk of the netlink attribute parsing is
done. That's because it is needed there.
Add a selftest to make sure the issue doesn't get reintroduced.
Fixes: 09dbdf28f9 ("net/sched: taprio: fix calculation of maximum gate durations")
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240527153955.553333-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
mono_delivery_time was added to check if skb->tstamp has delivery
time in mono clock base (i.e. EDT) otherwise skb->tstamp has
timestamp in ingress and delivery_time at egress.
Renaming the bitfield from mono_delivery_time to tstamp_type is for
extensibilty for other timestamps such as userspace timestamp
(i.e. SO_TXTIME) set via sock opts.
As we are renaming the mono_delivery_time to tstamp_type, it makes
sense to start assigning tstamp_type based on enum defined
in this commit.
Earlier we used bool arg flag to check if the tstamp is mono in
function skb_set_delivery_time, Now the signature of the functions
accepts tstamp_type to distinguish between mono and real time.
Also skb_set_delivery_type_by_clockid is a new function which accepts
clockid to determine the tstamp_type.
In future tstamp_type:1 can be extended to support userspace timestamp
by increasing the bitfield.
Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
