Joseph Huang [Wed, 16 Jul 2025 15:35:50 +0000 (11:35 -0400)]
net: bridge: Do not offload IGMP/MLD messages
Do not offload IGMP/MLD messages as it could lead to IGMP/MLD Reports
being unintentionally flooded to Hosts. Instead, let the bridge decide
where to send these IGMP/MLD messages.
Consider the case where the local host is sending out reports in response
to a remote querier like the following:
In the above setup, br0 will want to br_forward() reports for
mcast-listener-process's group(s) via swp1 to QUERIER; but since the
source hwdom is 0, the report is eligible for tx offloading, and is
flooded by hardware to both swp1 and swp2, reaching SOME-OTHER-HOST as
well. (Example and illustration provided by Tobias.)
Fixes: 472111920f1c ("net: bridge: switchdev: allow the TX data plane forwarding to be offloaded") Signed-off-by: Joseph Huang <Joseph.Huang@garmin.com> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20250716153551.1830255-1-Joseph.Huang@garmin.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: vlan: fix VLAN 0 refcount imbalance of toggling filtering during runtime
Assuming the "rx-vlan-filter" feature is enabled on a net device, the
8021q module will automatically add or remove VLAN 0 when the net device
is put administratively up or down, respectively. There are a couple of
problems with the above scheme.
The first problem is a memory leak that can happen if the "rx-vlan-filter"
feature is disabled while the device is running:
# ip link add bond1 up type bond mode 0
# ethtool -K bond1 rx-vlan-filter off
# ip link del dev bond1
When the device is put administratively down the "rx-vlan-filter"
feature is disabled, so the 8021q module will not remove VLAN 0 and the
memory will be leaked [1].
Another problem that can happen is that the kernel can automatically
delete VLAN 0 when the device is put administratively down despite not
adding it when the device was put administratively up since during that
time the "rx-vlan-filter" feature was disabled. null-ptr-unref or
bug_on[2] will be triggered by unregister_vlan_dev() for refcount
imbalance if toggling filtering during runtime:
$ ip link add bond0 type bond mode 0
$ ip link add link bond0 name vlan0 type vlan id 0 protocol 802.1q
$ ethtool -K bond0 rx-vlan-filter off
$ ifconfig bond0 up
$ ethtool -K bond0 rx-vlan-filter on
$ ifconfig bond0 down
$ ip link del vlan0
Root cause is as below:
step1: add vlan0 for real_dev, such as bond, team.
register_vlan_dev
vlan_vid_add(real_dev,htons(ETH_P_8021Q),0) //refcnt=1
step2: disable vlan filter feature and enable real_dev
step3: change filter from 0 to 1
vlan_device_event
vlan_filter_push_vids
ndo_vlan_rx_add_vid //No refcnt added to real_dev vlan0
step4: real_dev down
vlan_device_event
vlan_vid_del(dev, htons(ETH_P_8021Q), 0); //refcnt=0
vlan_info_rcu_free //free vlan0
step5: delete vlan0
unregister_vlan_dev
BUG_ON(!vlan_info); //vlan_info is null
Fix both problems by noting in the VLAN info whether VLAN 0 was
automatically added upon NETDEV_UP and based on that decide whether it
should be deleted upon NETDEV_DOWN, regardless of the state of the
"rx-vlan-filter" feature.
Jakub Kicinski [Thu, 17 Jul 2025 14:41:25 +0000 (07:41 -0700)]
Merge tag 'ovpn-net-20250716' of https://github.com/OpenVPN/ovpn-net-next
Antonio Quartulli says:
====================
This bugfix batch includes the following changes:
* properly propagate sk mark to skb->mark field
* reject unexpected incoming netlink attributes
* reset GSO state when moving skb from transport to tunnel layer
* tag 'ovpn-net-20250716' of https://github.com/OpenVPN/ovpn-net-next:
ovpn: reset GSO metadata after decapsulation
ovpn: reject unexpected netlink attributes
ovpn: propagate socket mark to skb in UDP
====================
Jakub Kicinski [Wed, 16 Jul 2025 14:38:50 +0000 (07:38 -0700)]
tls: always refresh the queue when reading sock
After recent changes in net-next TCP compacts skbs much more
aggressively. This unearthed a bug in TLS where we may try
to operate on an old skb when checking if all skbs in the
queue have matching decrypt state and geometry.
BUG: KASAN: slab-use-after-free in tls_strp_check_rcv+0x898/0x9a0 [tls]
(net/tls/tls_strp.c:436 net/tls/tls_strp.c:530 net/tls/tls_strp.c:544)
Read of size 4 at addr ffff888013085750 by task tls/13529
It happens if the VMM sends a VIRTIO_NET_S_ANNOUNCE request while the
virtio-net driver is still probing.
The config_work in probe() will get scheduled until virtnet_open() enables
the config change notification via virtio_config_driver_enable().
Fixes: df28de7b0050 ("virtio-net: synchronize operstate with admin state on up/down") Signed-off-by: Zigit Zo <zuozhijie@bytedance.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://patch.msgid.link/20250716115717.1472430-1-zuozhijie@bytedance.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Maor Gottlieb [Wed, 16 Jul 2025 07:29:29 +0000 (10:29 +0300)]
net/mlx5: Update the list of the PCI supported devices
Add the upcoming ConnectX-10 device ID to the table of supported
PCI device IDs.
Cc: stable@vger.kernel.org Signed-off-by: Maor Gottlieb <maorg@nvidia.com> Reviewed-by: Mark Bloch <mbloch@nvidia.com> Reviewed-by: Eran Ben Elisha <eranbe@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Link: https://patch.msgid.link/1752650969-148501-1-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Li Tian [Wed, 16 Jul 2025 00:26:05 +0000 (08:26 +0800)]
hv_netvsc: Set VF priv_flags to IFF_NO_ADDRCONF before open to prevent IPv6 addrconf
Set an additional flag IFF_NO_ADDRCONF to prevent ipv6 addrconf.
Commit under Fixes added a new flag change that was not made
to hv_netvsc resulting in the VF being assinged an IPv6.
Fixes: 8a321cf7becc ("net: add IFF_NO_ADDRCONF and use it in bonding to prevent ipv6 addrconf") Suggested-by: Cathy Avery <cavery@redhat.com> Signed-off-by: Li Tian <litian@redhat.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20250716002607.4927-1-litian@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
phonet/pep: Move call to pn_skb_get_dst_sockaddr() earlier in pep_sock_accept()
A new warning in clang [1] points out a place in pep_sock_accept() where
dst is uninitialized then passed as a const pointer to pep_find_pipe():
net/phonet/pep.c:829:37: error: variable 'dst' is uninitialized when passed as a const pointer argument here [-Werror,-Wuninitialized-const-pointer]
829 | newsk = pep_find_pipe(&pn->hlist, &dst, pipe_handle);
| ^~~:
Move the call to pn_skb_get_dst_sockaddr(), which initializes dst, to
before the call to pep_find_pipe(), so that dst is consistently used
initialized throughout the function.
Paolo Abeni [Thu, 17 Jul 2025 12:52:41 +0000 (14:52 +0200)]
Merge tag 'wireless-2025-07-17' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless
Johannes Berg says:
====================
Couple of fixes:
- ath12k performance regression from -rc1
- cfg80211 counted_by() removal for scan request
as it doesn't match usage and keeps complaining
- iwlwifi crash with certain older devices
- iwlwifi missing an error path unlock
- iwlwifi compatibility with certain BIOS updates
* tag 'wireless-2025-07-17' of https://git.kernel.org/pub/scm/linux/kernel/git/wireless/wireless:
wifi: iwlwifi: Fix botched indexing conversion
wifi: cfg80211: remove scan request n_channels counted_by
wifi: ath12k: Fix packets received in WBM error ring with REO LUT enabled
wifi: iwlwifi: mask reserved bits in chan_state_active_bitmap
wifi: iwlwifi: pcie: fix locking on invalid TOP reset
====================
Paolo Abeni [Thu, 17 Jul 2025 12:44:54 +0000 (14:44 +0200)]
Merge tag 'nf-25-07-17' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following batch contains Netfilter fixes for net:
1) Three patches to enhance conntrack selftests for resize and clash
resolution, from Florian Westphal.
2) Expand nft_concat_range.sh selftest to improve coverage from error
path, from Florian Westphal.
3) Hide clash bit to userspace from netlink dumps until there is a
good reason to expose, from Florian Westphal.
4) Revert notification for device registration/unregistration for
nftables basechains and flowtables, we decided to go for a better
way to handle this through the nfnetlink_hook infrastructure which
will come via nf-next, patch from Phil Sutter.
5) Fix crash in conntrack due to race related to SLAB_TYPESAFE_BY_RCU
that results in removing a recycled object that is not yet in the
hashes. Move IPS_CONFIRM setting after the object is in the hashes.
From Florian Westphal.
netfilter pull request 25-07-17
* tag 'nf-25-07-17' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_conntrack: fix crash due to removal of uninitialised entry
Revert "netfilter: nf_tables: Add notifications for hook changes"
netfilter: nf_tables: hide clash bit from userspace
selftests: netfilter: nft_concat_range.sh: send packets to empty set
selftests: netfilter: conntrack_resize.sh: also use udpclash tool
selftests: netfilter: add conntrack clash resolution test case
selftests: netfilter: conntrack_resize.sh: extend resize test
====================
netfilter: nf_conntrack: fix crash due to removal of uninitialised entry
A crash in conntrack was reported while trying to unlink the conntrack
entry from the hash bucket list:
[exception RIP: __nf_ct_delete_from_lists+172]
[..]
#7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack]
#8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack]
#9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack]
[..]
The nf_conn struct is marked as allocated from slab but appears to be in
a partially initialised state:
ct hlist pointer is garbage; looks like the ct hash value
(hence crash).
ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected
ct->timeout is 30000 (=30s), which is unexpected.
Everything else looks like normal udp conntrack entry. If we ignore
ct->status and pretend its 0, the entry matches those that are newly
allocated but not yet inserted into the hash:
- ct hlist pointers are overloaded and store/cache the raw tuple hash
- ct->timeout matches the relative time expected for a new udp flow
rather than the absolute 'jiffies' value.
If it were not for the presence of IPS_CONFIRMED,
__nf_conntrack_find_get() would have skipped the entry.
Theory is that we did hit following race:
cpu x cpu y cpu z
found entry E found entry E
E is expired <preemption>
nf_ct_delete()
return E to rcu slab
init_conntrack
E is re-inited,
ct->status set to 0
reply tuplehash hnnode.pprev
stores hash value.
cpu y found E right before it was deleted on cpu x.
E is now re-inited on cpu z. cpu y was preempted before
checking for expiry and/or confirm bit.
->refcnt set to 1
E now owned by skb
->timeout set to 30000
If cpu y were to resume now, it would observe E as
expired but would skip E due to missing CONFIRMED bit.
nf_conntrack_confirm gets called
sets: ct->status |= CONFIRMED
This is wrong: E is not yet added
to hashtable.
cpu y resumes, it observes E as expired but CONFIRMED:
<resumes>
nf_ct_expired()
-> yes (ct->timeout is 30s)
confirmed bit set.
cpu y will try to delete E from the hashtable:
nf_ct_delete() -> set DYING bit
__nf_ct_delete_from_lists
Even this scenario doesn't guarantee a crash:
cpu z still holds the table bucket lock(s) so y blocks:
wait for spinlock held by z
CONFIRMED is set but there is no
guarantee ct will be added to hash:
"chaintoolong" or "clash resolution"
logic both skip the insert step.
reply hnnode.pprev still stores the
hash value.
unlocks spinlock
return NF_DROP
<unblocks, then
crashes on hlist_nulls_del_rcu pprev>
In case CPU z does insert the entry into the hashtable, cpu y will unlink
E again right away but no crash occurs.
Without 'cpu y' race, 'garbage' hlist is of no consequence:
ct refcnt remains at 1, eventually skb will be free'd and E gets
destroyed via: nf_conntrack_put -> nf_conntrack_destroy -> nf_ct_destroy.
To resolve this, move the IPS_CONFIRMED assignment after the table
insertion but before the unlock.
Pablo points out that the confirm-bit-store could be reordered to happen
before hlist add resp. the timeout fixup, so switch to set_bit and
before_atomic memory barrier to prevent this.
It doesn't matter if other CPUs can observe a newly inserted entry right
before the CONFIRMED bit was set:
Such event cannot be distinguished from above "E is the old incarnation"
case: the entry will be skipped.
Also change nf_ct_should_gc() to first check the confirmed bit.
The gc sequence is:
1. Check if entry has expired, if not skip to next entry
2. Obtain a reference to the expired entry.
3. Call nf_ct_should_gc() to double-check step 1.
nf_ct_should_gc() is thus called only for entries that already failed an
expiry check. After this patch, once the confirmed bit check passes
ct->timeout has been altered to reflect the absolute 'best before' date
instead of a relative time. Step 3 will therefore not remove the entry.
Without this change to nf_ct_should_gc() we could still get this sequence:
1. Check if entry has expired.
2. Obtain a reference.
3. Call nf_ct_should_gc() to double-check step 1:
4 - entry is still observed as expired
5 - meanwhile, ct->timeout is corrected to absolute value on other CPU
and confirm bit gets set
6 - confirm bit is seen
7 - valid entry is removed again
First do check 6), then 4) so the gc expiry check always picks up either
confirmed bit unset (entry gets skipped) or expiry re-check failure for
re-inited conntrack objects.
This change cannot be backported to releases before 5.19. Without
commit 8a75a2c17410 ("netfilter: conntrack: remove unconfirmed list")
|= IPS_CONFIRMED line cannot be moved without further changes.
Felix Fietkau [Sat, 5 Jul 2025 15:06:21 +0000 (17:06 +0200)]
net: fix segmentation after TCP/UDP fraglist GRO
Since "net: gro: use cb instead of skb->network_header", the skb network
header is no longer set in the GRO path.
This breaks fraglist segmentation, which relies on ip_hdr()/tcp_hdr()
to check for address/port changes.
Fix this regression by selectively setting the network header for merged
segment skbs.
Fixes: 186b1ea73ad8 ("net: gro: use cb instead of skb->network_header") Signed-off-by: Felix Fietkau <nbd@nbd.name> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20250705150622.10699-1-nbd@nbd.name Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Arnd Bergmann resolves compile issues with large NR_CPUS for ixgbe, fm10k,
and i40e.
For ice:
Dave adds a NULL check for LAG netdev.
Michal corrects a pointer check in debugfs initialization.
* '100GbE' of git://git.kernel.org/pub/scm/linux/kernel/git/tnguy/net-queue:
ice: check correct pointer in fwlog debugfs
ice: add NULL check in eswitch lag check
ethernet: intel: fix building with large NR_CPUS
====================
net: airoha: fix potential use-after-free in airoha_npu_get()
np->name was being used after calling of_node_put(np), which
releases the node and can lead to a use-after-free bug.
Previously, of_node_put(np) was called unconditionally after
of_find_device_by_node(np), which could result in a use-after-free if
pdev is NULL.
This patch moves of_node_put(np) after the error check to ensure
the node is only released after both the error and success cases
are handled appropriately, preventing potential resource issues.
Christoph Paasch [Tue, 15 Jul 2025 20:20:53 +0000 (13:20 -0700)]
net/mlx5: Correctly set gso_size when LRO is used
gso_size is expected by the networking stack to be the size of the
payload (thus, not including ethernet/IP/TCP-headers). However, cqe_bcnt
is the full sized frame (including the headers). Dividing cqe_bcnt by
lro_num_seg will then give incorrect results.
For example, running a bpftrace higher up in the TCP-stack
(tcp_event_data_recv), we commonly have gso_size set to 1450 or 1451 even
though in reality the payload was only 1448 bytes.
This can have unintended consequences:
- In tcp_measure_rcv_mss() len will be for example 1450, but. rcv_mss
will be 1448 (because tp->advmss is 1448). Thus, we will always
recompute scaling_ratio each time an LRO-packet is received.
- In tcp_gro_receive(), it will interfere with the decision whether or
not to flush and thus potentially result in less gro'ed packets.
So, we need to discount the protocol headers from cqe_bcnt so we can
actually divide the payload by lro_num_seg to get the real gso_size.
The ovpn_netdev_write() function is responsible for injecting
decapsulated and decrypted packets back into the local network stack.
Prior to this patch, the skb could retain GSO metadata from the outer,
encrypted tunnel packet. This original GSO metadata, relevant to the
sender's transport context, becomes invalid and misleading for the
tunnel/data path once the inner packet is exposed.
Leaving this stale metadata intact causes internal GSO validation checks
further down the kernel's network stack (validate_xmit_skb()) to fail,
leading to packet drops. The reasons for these failures vary by
protocol, for example:
- for ICMP, no offload handler is registered;
- for TCP and UDP, the respective offload handlers return errors when
comparing skb->len to the outdated skb_shinfo(skb)->gso_size.
By calling skb_gso_reset(skb) we ensure the inner packet is presented to
gro_cells_receive() with a clean state, correctly indicating it is an
individual packet from the perspective of the local stack.
This change eliminates the "Driver has suspect GRO implementation, TCP
performance may be compromised" warning and improves overall TCP
performance by allowing GSO/GRO to function as intended on the
decapsulated traffic.
Fixes: 11851cbd60ea ("ovpn: implement TCP transport") Reported-by: Gert Doering <gert@greenie.muc.de> Closes: https://github.com/OpenVPN/ovpn-net-next/issues/4 Tested-by: Gert Doering <gert@greenie.muc.de> Signed-off-by: Ralf Lici <ralf@mandelbit.com> Signed-off-by: Antonio Quartulli <antonio@openvpn.net>
Netlink ops do not expect all attributes to be always set, however
this condition is not explicitly coded any where, leading the user
to believe that all sent attributes are somewhat processed.
Fix this behaviour by introducing explicit checks.
For CMD_OVPN_PEER_GET and CMD_OVPN_KEY_GET directly open-code the
needed condition in the related ops handlers.
While for all other ops use attribute subsets in the ovpn.yaml spec file.
Ralf Lici [Wed, 4 Jun 2025 13:11:58 +0000 (15:11 +0200)]
ovpn: propagate socket mark to skb in UDP
OpenVPN allows users to configure a FW mark on sockets used to
communicate with other peers. The mark is set by means of the
`SO_MARK` Linux socket option.
However, in the ovpn UDP code path, the socket's `sk_mark` value is
currently ignored and it is not propagated to outgoing `skbs`.
This commit ensures proper inheritance of the field by setting
`skb->mark` to `sk->sk_mark` before handing the `skb` to the network
stack for transmission.
This series contains 3 fixes somewhat related to various races we have
while handling fallback.
The root cause of the issues addressed here is that the check for
"we can fallback to tcp now" and the related action are not atomic. That
also applies to fallback due to MP_FAIL -- where the window race is even
wider.
Address the issue introducing an additional spinlock to bundle together
all the relevant events, as per patch 1 and 2. These fixes can be
backported up to v5.19 and v5.15.
Note that mptcp_disconnect() unconditionally clears the fallback status
(zeroing msk->flags) but don't touch the `allows_infinite_fallback`
flag. Such issue is addressed in patch 3, and can be backported up to
v5.17.
====================
Paolo Abeni [Mon, 14 Jul 2025 16:41:46 +0000 (18:41 +0200)]
mptcp: reset fallback status gracefully at disconnect() time
mptcp_disconnect() clears the fallback bit unconditionally, without
touching the associated flags.
The bit clear is safe, as no fallback operation can race with that --
all subflow are already in TCP_CLOSE status thanks to the previous
FASTCLOSE -- but we need to consistently reset all the fallback related
status.
Also acquire the relevant lock, to avoid fouling static analyzers.
Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-3-391aff963322@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Paolo Abeni [Mon, 14 Jul 2025 16:41:45 +0000 (18:41 +0200)]
mptcp: plug races between subflow fail and subflow creation
We have races similar to the one addressed by the previous patch between
subflow failing and additional subflow creation. They are just harder to
trigger.
The solution is similar. Use a separate flag to track the condition
'socket state prevent any additional subflow creation' protected by the
fallback lock.
The socket fallback makes such flag true, and also receiving or sending
an MP_FAIL option.
The field 'allow_infinite_fallback' is now always touched under the
relevant lock, we can drop the ONCE annotation on write.
Fixes: 478d770008b0 ("mptcp: send out MP_FAIL when data checksum fails") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250714-net-mptcp-fallback-races-v1-2-391aff963322@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since we need to track the 'fallback is possible' condition and the
fallback status separately, there are a few possible races open between
the check and the actual fallback action.
Add a spinlock to protect the fallback related information and use it
close all the possible related races. While at it also remove the
too-early clearing of allow_infinite_fallback in __mptcp_subflow_connect():
the field will be correctly cleared by subflow_finish_connect() if/when
the connection will complete successfully.
If fallback is not possible, as per RFC, reset the current subflow.
Since the fallback operation can now fail and return value should be
checked, rename the helper accordingly.
Multicast good packets received by PF rings that pass ethternet MAC
address filtering are counted for rtnl_link_stats64.multicast. The
counter is not cleared on read. Fix the duplicate counting on updating
statistics.
When device reset is triggered by feature changes such as toggling Rx
VLAN offload, wx->do_reset() is called to reinitialize Rx rings. The
hardware descriptor ring may retain stale values from previous sessions.
And only set the length to 0 in rx_desc[0] would result in building
malformed SKBs. Fix it to ensure a clean slate after device reset.
The wx_rx_buffer structure contained two DMA address fields: 'dma' and
'page_dma'. However, only 'page_dma' was actually initialized and used
to program the Rx descriptor. But 'dma' was uninitialized and used in
some paths.
This could lead to undefined behavior, including DMA errors or
use-after-free, if the uninitialized 'dma' was used. Althrough such
error has not yet occurred, it is worth fixing in the code.
Fixes: 3c47e8ae113a ("net: libwx: Support to receive packets in NAPI") Cc: stable@vger.kernel.org Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250714024755.17512-3-jiawenwu@trustnetic.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
page_pool_put_full_page() should only be invoked when freeing Rx buffers
or building a skb if the size is too short. At other times, the pages
need to be reused. So remove the redundant page put. In the original
code, double free pages cause kernel panic:
Jakub Kicinski [Tue, 15 Jul 2025 23:05:41 +0000 (16:05 -0700)]
Merge tag 'linux-can-fixes-for-6.16-20250715' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says:
====================
pull-request: can 2025-07-15
Brett Werling's patch for the tcan4x5x glue code driver fixes the
detection of chips which are held in reset/sleep and must be woken up
by GPIO prior to communication.
* tag 'linux-can-fixes-for-6.16-20250715' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
can: tcan4x5x: fix reset gpio usage during probe
====================
Oliver Neukum [Mon, 14 Jul 2025 11:12:56 +0000 (13:12 +0200)]
usb: net: sierra: check for no status endpoint
The driver checks for having three endpoints and
having bulk in and out endpoints, but not that
the third endpoint is interrupt input.
Rectify the omission.
Dave Ertman [Thu, 22 May 2025 17:16:57 +0000 (13:16 -0400)]
ice: add NULL check in eswitch lag check
The function ice_lag_is_switchdev_running() is being called from outside of
the LAG event handler code. This results in the lag->upper_netdev being
NULL sometimes. To avoid a NULL-pointer dereference, there needs to be a
check before it is dereferenced.
Fixes: 776fe19953b0 ("ice: block default rule setting on LAG interface") Signed-off-by: Dave Ertman <david.m.ertman@intel.com> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Tested-by: Sujai Buvaneswaran <sujai.buvaneswaran@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Arnd Bergmann [Fri, 20 Jun 2025 17:31:24 +0000 (19:31 +0200)]
ethernet: intel: fix building with large NR_CPUS
With large values of CONFIG_NR_CPUS, three Intel ethernet drivers fail to
compile like:
In function ‘i40e_free_q_vector’,
inlined from ‘i40e_vsi_alloc_q_vectors’ at drivers/net/ethernet/intel/i40e/i40e_main.c:12112:3:
571 | _compiletime_assert(condition, msg, __compiletime_assert_, __COUNTER__)
include/linux/rcupdate.h:1084:17: note: in expansion of macro ‘BUILD_BUG_ON’
1084 | BUILD_BUG_ON(offsetof(typeof(*(ptr)), rhf) >= 4096); \
drivers/net/ethernet/intel/i40e/i40e_main.c:5113:9: note: in expansion of macro ‘kfree_rcu’
5113 | kfree_rcu(q_vector, rcu);
| ^~~~~~~~~
The problem is that the 'rcu' member in 'q_vector' is too far from the start
of the structure. Move this member before the CPU mask instead, in all three
drivers.
Signed-off-by: Arnd Bergmann <arnd@arndb.de> Acked-by: David S. Miller <davem@davemloft.net> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Reviewed-by: Alexander Lobakin <aleksander.lobakin@intel.com> Tested-by: Sunitha Mekala <sunithax.d.mekala@intel.com> (A Contingent worker at Intel) Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Paolo Abeni [Thu, 10 Jul 2025 16:04:50 +0000 (18:04 +0200)]
selftests: net: increase inter-packet timeout in udpgro.sh
The mentioned test is not very stable when running on top of
debug kernel build. Increase the inter-packet timeout to allow
more slack in such environments.
Fixes reset GPIO usage during probe by ensuring we retrieve the GPIO and
take the device out of reset (if it defaults to being in reset) before
we attempt to communicate with the device. This is achieved by moving
the call to tcan4x5x_get_gpios() before tcan4x5x_find_version() and
avoiding any device communication while getting the GPIOs. Once we
determine the version, we can then take the knowledge of which GPIOs we
obtained and use it to decide whether we need to disable the wake or
state pin functions within the device.
This change is necessary in a situation where the reset GPIO is pulled
high externally before the CPU takes control of it, meaning we need to
explicitly bring the device out of reset before we can start
communicating with it at all.
This also has the effect of fixing an issue where a reset of the device
would occur after having called tcan4x5x_disable_wake(), making the
original behavior not actually disable the wake. This patch should now
disable wake or state pin functions well after the reset occurs.
Signed-off-by: Brett Werling <brett.werling@garmin.com> Link: https://patch.msgid.link/20250711141728.1826073-1-brett.werling@garmin.com Cc: Markus Schneider-Pargmann <msp@baylibre.com> Fixes: 142c6dc6d9d7 ("can: tcan4x5x: Add support for tcan4552/4553") Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Ville Syrjälä [Fri, 11 Jul 2025 20:57:44 +0000 (23:57 +0300)]
wifi: iwlwifi: Fix botched indexing conversion
The conversion from compiler assisted indexing to manual
indexing wasn't done correctly. The array is still made
up of __le16 elements so multiplying the outer index by
the element size is not what we want. Fix it up.
This causes the kernel to oops when trying to transfer any
significant amount of data over wifi:
Cc: Miri Korenblit <miriam.rachel.korenblit@intel.com> Fixes: 6204d5130a64 ("wifi: iwlwifi: use bc entries instead of bc table also for pre-ax210") Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patch.msgid.link/20250711205744.28723-1-ville.syrjala@linux.intel.com Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
This reverts commit e3eac9f32ec0 ("wifi: cfg80211: Annotate struct
cfg80211_scan_request with __counted_by").
This really has been a completely failed experiment. There were
no actual bugs found, and yet at this point we already have four
"fixes" to it, with nothing to show for but code churn, and it
never even made the code any safer.
In all of the cases that ended up getting "fixed", the structure
is also internally inconsistent after the n_channels setting as
the channel list isn't actually filled yet. You cannot scan with
such a structure, that's just wrong. In mac80211, the struct is
also reused multiple times, so initializing it once is no good.
Some previous "fixes" (e.g. one in brcm80211) are also just setting
n_channels before accessing the array, under the assumption that the
code is correct and the array can be accessed, further showing that
the whole thing is just pointless when the allocation count and use
count are not separate.
If we really wanted to fix it, we'd need to separately track the
number of channels allocated and the number of channels currently
used, but given that no bugs were found despite the numerous syzbot
reports, that'd just be a waste of time.
Remove the __counted_by() annotation. We really should also remove
a number of the n_channels settings that are setting up a structure
that's inconsistent, but that can wait.
Sean Anderson [Mon, 7 Jul 2025 19:58:03 +0000 (15:58 -0400)]
net: phy: Don't register LEDs for genphy
If a PHY has no driver, the genphy driver is probed/removed directly in
phy_attach/detach. If the PHY's ofnode has an "leds" subnode, then the
LEDs will be (un)registered when probing/removing the genphy driver.
This could occur if the leds are for a non-generic driver that isn't
loaded for whatever reason. Synchronously removing the PHY device in
phy_detach leads to the following deadlock:
There is a corresponding deadlock on the open/register side of things
(and that one is reported by lockdep), but it requires a race while this
one is deterministic.
Generic PHYs do not support LEDs anyway, so don't bother registering
them.
Victor Nogueira [Sat, 12 Jul 2025 14:50:35 +0000 (11:50 -0300)]
selftests/tc-testing: Create test cases for adding qdiscs to invalid qdisc parents
As described in a previous commit [1], Lion's patch [2] revealed an ancient
bug in the qdisc API. Whenever a user tries to add a qdisc to an
invalid parent (not a class, root, or ingress qdisc), the qdisc API will
detect this after qdisc_create is called. Some qdiscs (like fq_codel, pie,
and sfq) call functions (on their init callback) which assume the parent is
valid, so qdisc_create itself may have caused a NULL pointer dereference in
such cases.
This commit creates 3 TDC tests that attempt to add fq_codel, pie and sfq
qdiscs to invalid parents
- Attempts to add an fq_codel qdisc to an hhf qdisc parent
- Attempts to add a pie qdisc to a drr qdisc parent
- Attempts to add an sfq qdisc to an inexistent hfsc classid (which would
belong to a valid hfsc qdisc)
smc: Fix various oops due to inet_sock type confusion.
syzbot reported weird splats [0][1] in cipso_v4_sock_setattr() while
freeing inet_sk(sk)->inet_opt.
The address was freed multiple times even though it was read-only memory.
cipso_v4_sock_setattr() did nothing wrong, and the root cause was type
confusion.
The cited commit made it possible to create smc_sock as an INET socket.
The issue is that struct smc_sock does not have struct inet_sock as the
first member but hijacks AF_INET and AF_INET6 sk_family, which confuses
various places.
In this case, inet_sock.inet_opt was actually smc_sock.clcsk_data_ready(),
which is an address of a function in the text segment.
netfilter: nf_tables: hide clash bit from userspace
Its a kernel implementation detail, at least at this time:
We can later decide to revert this patch if there is a compelling
reason, but then we should also remove the ifdef that prevents exposure
of ip_conntrack_status enum IPS_NAT_CLASH value in the uapi header.
Clash entries are not included in dumps (true for both old /proc
and ctnetlink) either. So for now exclude the clash bit when dumping.
Fixes: 7e5c6aa67e6f ("netfilter: nf_tables: add packets conntrack state to debug trace info") Link: https://lore.kernel.org/netfilter-devel/aGwf3dCggwBlRKKC@strlen.de/ Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphal [Fri, 27 Jun 2025 14:27:51 +0000 (16:27 +0200)]
selftests: netfilter: add conntrack clash resolution test case
Add a dedicated test to exercise conntrack clash resolution path.
Test program emits 128 identical udp packets in parallel, then reads
back replies from socat echo server.
Also check (via conntrack -S) that the clash path was hit at least once.
Due to the racy nature of the test its possible that despite the
threaded program all packets were processed in-order or on same cpu,
emit a SKIP warning in this case.
Two tests are added:
- one to test the simpler, non-nat case
- one to exercise clash resolution where packets
might have different nat transformations attached to them.
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Florian Westphal [Fri, 27 Jun 2025 14:27:50 +0000 (16:27 +0200)]
selftests: netfilter: conntrack_resize.sh: extend resize test
Extend the resize test:
- continuously dump table both via /proc and ctnetlink interfaces while
table is resized in a loop.
- if socat is available, send udp packets in additon to ping requests.
- increase/decrease the icmp and udp timeouts while resizes are happening.
This makes sure we also exercise the 'ct has expired' check that happens
on conntrack lookup.
Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The buggy address belongs to the object at ffff888122bf96c0
which belongs to the cache skbuff_small_head of size 704
The buggy address is located 24 bytes inside of
freed 704-byte region [ffff888122bf96c0, ffff888122bf9980)
Memory state around the buggy address: ffff888122bf9580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888122bf9600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888122bf9680: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^ ffff888122bf9700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888122bf9780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Fixes: a7a29f9c361f8 ("net: ipv6: add rpl sr tunnel") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Sun, 13 Jul 2025 00:28:52 +0000 (01:28 +0100)]
Merge branch 'tpacket_snd-bugs' into main
Yun Lu says:
====================
fix two issues and optimize code on tpacket_snd()
This series fix two issues and optimize the code on tpacket_snd():
1, fix the SO_SNDTIMEO constraint not effective due to the changes in
commit 581073f626e3;
2, fix a soft lockup issue on a specific edge case, and also optimize
the loop logic to be clearer and more obvious;
---
Changes in v5:
- Still combine fix and optimization together, change to while(1).
Thanks: Willem de Bruijn.
- Link to v4: https://lore.kernel.org/all/20250710102639.280932-1-luyun_611@163.com/
Changes in v4:
- Fix a typo and add the missing semicolon. Thanks: Simon Horman.
- Split the second patch into two, one to fix, another to optimize.
Thanks: Willem de Bruijn
- Link to v3: https://lore.kernel.org/all/20250709095653.62469-1-luyun_611@163.com/
Changes in v3:
- Split in two different patches.
- Simplify the code and reuse ph to continue. Thanks: Eric Dumazet.
- Link to v2: https://lore.kernel.org/all/20250708020642.27838-1-luyun_611@163.com/
Changes in v2:
- Add a Fixes tag.
- Link to v1: https://lore.kernel.org/all/20250707081629.10344-1-luyun_611@163.com/
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Yun Lu [Fri, 11 Jul 2025 09:33:00 +0000 (17:33 +0800)]
af_packet: fix soft lockup issue caused by tpacket_snd()
When MSG_DONTWAIT is not set, the tpacket_snd operation will wait for
pending_refcnt to decrement to zero before returning. The pending_refcnt
is decremented by 1 when the skb->destructor function is called,
indicating that the skb has been successfully sent and needs to be
destroyed.
If an error occurs during this process, the tpacket_snd() function will
exit and return error, but pending_refcnt may not yet have decremented to
zero. Assuming the next send operation is executed immediately, but there
are no available frames to be sent in tx_ring (i.e., packet_current_frame
returns NULL), and skb is also NULL, the function will not execute
wait_for_completion_interruptible_timeout() to yield the CPU. Instead, it
will enter a do-while loop, waiting for pending_refcnt to be zero. Even
if the previous skb has completed transmission, the skb->destructor
function can only be invoked in the ksoftirqd thread (assuming NAPI
threading is enabled). When both the ksoftirqd thread and the tpacket_snd
operation happen to run on the same CPU, and the CPU trapped in the
do-while loop without yielding, the ksoftirqd thread will not get
scheduled to run. As a result, pending_refcnt will never be reduced to
zero, and the do-while loop cannot exit, eventually leading to a CPU soft
lockup issue.
In fact, skb is true for all but the first iterations of that loop, and
as long as pending_refcnt is not zero, even if incremented by a previous
call, wait_for_completion_interruptible_timeout() should be executed to
yield the CPU, allowing the ksoftirqd thread to be scheduled. Therefore,
the execution condition of this function should be modified to check if
pending_refcnt is not zero, instead of check skb.
- if (need_wait && skb) {
+ if (need_wait && packet_read_pending(&po->tx_ring)) {
As a result, the judgment conditions are duplicated with the end code of
the while loop, and packet_read_pending() is a very expensive function.
Actually, this loop can only exit when ph is NULL, so the loop condition
can be changed to while (1), and in the "ph = NULL" branch, if the
subsequent condition of if is not met, the loop can break directly. Now,
the loop logic remains the same as origin but is clearer and more obvious.
Fixes: 89ed5b519004 ("af_packet: Block execution of tasks waiting for transmit to complete in AF_PACKET") Cc: stable@kernel.org Suggested-by: LongJun Tang <tanglongjun@kylinos.cn> Signed-off-by: Yun Lu <luyun@kylinos.cn> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Yun Lu [Fri, 11 Jul 2025 09:32:59 +0000 (17:32 +0800)]
af_packet: fix the SO_SNDTIMEO constraint not effective on tpacked_snd()
Due to the changes in commit 581073f626e3 ("af_packet: do not call
packet_read_pending() from tpacket_destruct_skb()"), every time
tpacket_destruct_skb() is executed, the skb_completion is marked as
completed. When wait_for_completion_interruptible_timeout() returns
completed, the pending_refcnt has not yet been reduced to zero.
Therefore, when ph is NULL, the wait function may need to be called
multiple times until packet_read_pending() finally returns zero.
We should call sock_sndtimeo() only once, otherwise the SO_SNDTIMEO
constraint could be way off.
Fixes: 581073f626e3 ("af_packet: do not call packet_read_pending() from tpacket_destruct_skb()") Cc: stable@kernel.org Suggested-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Yun Lu <luyun@kylinos.cn> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Xiang Mei [Thu, 10 Jul 2025 10:09:42 +0000 (03:09 -0700)]
net/sched: sch_qfq: Fix race condition on qfq_aggregate
A race condition can occur when 'agg' is modified in qfq_change_agg
(called during qfq_enqueue) while other threads access it
concurrently. For example, qfq_dump_class may trigger a NULL
dereference, and qfq_delete_class may cause a use-after-free.
This patch addresses the issue by:
1. Moved qfq_destroy_class into the critical section.
2. Added sch_tree_lock protection to qfq_dump_class and
qfq_dump_class_stats.
Fixes: 462dbc9101ac ("pkt_sched: QFQ Plus: fair-queueing service at DRR cost") Signed-off-by: Xiang Mei <xmei5@asu.edu> Reviewed-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
net: emaclite: Fix missing pointer increment in aligned_read()
Add missing post-increment operators for byte pointers in the
loop that copies remaining bytes in xemaclite_aligned_read().
Without the increment, the same byte was written repeatedly
to the destination.
This update aligns with xemaclite_aligned_write()
Merge tag 'net-6.16-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull more networking fixes from Jakub Kicinski
"Big chunk of fixes for WiFi, Johannes says probably the last for the
release.
The Netlink fixes (on top of the tree) restore operation of iw (WiFi
CLI) which uses sillily small recv buffer, and is the reason for this
'emergency PR'.
The GRE multicast fix also stands out among the user-visible
regressions.
Current release - fix to a fix:
- netlink: make sure we always allow at least one skb to be queued,
even if the recvbuf is (mis)configured to be tiny
Previous releases - regressions:
- gre: fix IPv6 multicast route creation
Previous releases - always broken:
- wifi: prevent A-MSDU attacks in mesh networks
- wifi: cfg80211: fix S1G beacon head validation and detection
- wifi: mac80211:
- always clear frame buffer to prevent stack leak in cases which
hit a WARN()
- fix monitor interface in device restart
- wifi: mwifiex: discard erroneous disassoc frames on STA interface
- wifi: mt76:
- prevent null-deref in mt7925_sta_set_decap_offload()
- add missing RCU annotations, and fix sleep in atomic
- fix decapsulation offload
- fixes for scanning
- phy: microchip: improve link establishment and reset handling
- eth: mlx5e: fix race between DIM disable and net_dim()
- bnxt_en: correct DMA unmap len for XDP_REDIRECT"
* tag 'net-6.16-rc6-2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (44 commits)
netlink: make sure we allow at least one dump skb
netlink: Fix rmem check in netlink_broadcast_deliver().
bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT
bnxt_en: Flush FW trace before copying to the coredump
bnxt_en: Fix DCB ETS validation
net: ll_temac: Fix missing tx_pending check in ethtools_set_ringparam()
net/mlx5e: Add new prio for promiscuous mode
net/mlx5e: Fix race between DIM disable and net_dim()
net/mlx5: Reset bw_share field when changing a node's parent
can: m_can: m_can_handle_lost_msg(): downgrade msg lost in rx message to debug level
selftests: net: lib: fix shift count out of range
selftests: Add IPv6 multicast route generation tests for GRE devices.
gre: Fix IPv6 multicast route creation.
net: phy: microchip: limit 100M workaround to link-down events on LAN88xx
net: phy: microchip: Use genphy_soft_reset() to purge stale LPA bits
ibmvnic: Fix hardcoded NUM_RX_STATS/NUM_TX_STATS with dynamic sizeof
net: appletalk: Fix device refcount leak in atrtr_create()
netfilter: flowtable: account for Ethernet header in nf_flow_pppoe_proto()
wifi: mac80211: add the virtual monitor after reconfig complete
wifi: mac80211: always initialize sdata::key_list
...
Merge tag 'gpio-fixes-for-v6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux
Pull gpio fixes from Bartosz Golaszewski:
- fix performance regression when setting values of multiple GPIO lines
at once
- make sure the GPIO OF xlate code doesn't end up passing an
uninitialized local variable to GPIO core
- update MAINTAINERS
* tag 'gpio-fixes-for-v6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
MAINTAINERS: remove bouncing address for Nandor Han
gpio: of: initialize local variable passed to the .of_xlate() callback
gpiolib: fix performance regression when using gpio_chip_get_multiple()
Merge tag 'dma-mapping-6.16-2025-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping fix from Marek Szyprowski:
- small fix relevant to arm64 server and custom CMA configuration (Feng
Tang)
* tag 'dma-mapping-6.16-2025-07-11' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
dma-contiguous: hornor the cma address limit setup by user
wifi: ath12k: Fix packets received in WBM error ring with REO LUT enabled
Currently, packets are being received into the WBM error ring when
REO queue lookup is enabled, resulting in degraded RX performance.
The issue arises because the REO queue LUT TID memory reference is
set to zero-it's being assigned before the memory is allocated.
Fix this by assigning the REO queue TID memory reference in the LUT
immediately after memory allocation to ensure correct packet
processing.
Jakub Kicinski [Fri, 11 Jul 2025 00:11:21 +0000 (17:11 -0700)]
netlink: make sure we allow at least one dump skb
Commit under Fixes tightened up the memory accounting for Netlink
sockets. Looks like the accounting is too strict for some existing
use cases, Marek reported issues with nl80211 / WiFi iw CLI.
To reduce number of iterations Netlink dumps try to allocate
messages based on the size of the buffer passed to previous
recvmsg() calls. If user space uses a larger buffer in recvmsg()
than sk_rcvbuf we will allocate an skb we won't be able to queue.
Make sure we always allow at least one skb to be queued.
Same workaround is already present in netlink_attachskb().
Alternative would be to cap the allocation size to
rcvbuf - rmem_alloc
but as I said, the workaround is already present in other places.
Jakub Kicinski [Fri, 11 Jul 2025 14:28:36 +0000 (07:28 -0700)]
Merge branch 'bnxt_en-3-bug-fixes'
Michael Chan says:
====================
bnxt_en: 3 bug fixes
The first one fixes a possible failure when setting DCB ETS.
The second one fixes the ethtool coredump (-W 2) not containing
all the FW traces. The third one fixes the DMA unmap length when
transmitting XDP_REDIRECT packets.
====================
bnxt_en: Set DMA unmap len correctly for XDP_REDIRECT
When transmitting an XDP_REDIRECT packet, call dma_unmap_len_set()
with the proper length instead of 0. This bug triggers this warning
on a system with IOMMU enabled:
bnxt_en: Flush FW trace before copying to the coredump
bnxt_fill_drv_seg_record() calls bnxt_dbg_hwrm_log_buffer_flush()
to flush the FW trace buffer. This needs to be done before we
call bnxt_copy_ctx_mem() to copy the trace data.
Without this fix, the coredump may not contain all the FW
traces.
Fixes: 3c2179e66355 ("bnxt_en: Add FW trace coredump segments to the coredump") Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com> Signed-off-by: Shruti Parab <shruti.parab@broadcom.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Link: https://patch.msgid.link/20250710213938.1959625-3-michael.chan@broadcom.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In bnxt_ets_validate(), the code incorrectly loops over all possible
traffic classes to check and add the ETS settings. Fix it to loop
over the configured traffic classes only.
The unconfigured traffic classes will default to TSA_ETS with 0
bandwidth. Looping over these unconfigured traffic classes may
cause the validation to fail and trigger this error message:
"rejecting ETS config starving a TC\n"
The .ieee_setets() will then fail.
Fixes: 7df4ae9fe855 ("bnxt_en: Implement DCBNL to support host-based DCBX.") Reviewed-by: Sreekanth Reddy <sreekanth.reddy@broadcom.com> Signed-off-by: Shravya KN <shravya.k-n@broadcom.com> Signed-off-by: Michael Chan <michael.chan@broadcom.com> Link: https://patch.msgid.link/20250710213938.1959625-2-michael.chan@broadcom.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: ll_temac: Fix missing tx_pending check in ethtools_set_ringparam()
The function ll_temac_ethtools_set_ringparam() incorrectly checked
rx_pending twice, once correctly for RX and once mistakenly in place
of tx_pending. This caused tx_pending to be left unchecked against
TX_BD_NUM_MAX.
As a result, invalid TX ring sizes may have been accepted or valid
ones wrongly rejected based on the RX limit, leading to potential
misconfiguration or unexpected results.
This patch corrects the condition to properly validate tx_pending.
Jianbo Liu [Thu, 10 Jul 2025 13:53:44 +0000 (16:53 +0300)]
net/mlx5e: Add new prio for promiscuous mode
An optimization for promiscuous mode adds a high-priority steering
table with a single catch-all rule to steer all traffic directly to
the TTC table.
However, a gap exists between the creation of this table and the
insertion of the catch-all rule. Packets arriving in this brief window
would miss as no rule was inserted yet, unnecessarily incrementing the
'rx_steer_missed_packets' counter and dropped.
This patch resolves the issue by introducing a new prio for this
table, placing it between MLX5E_TC_PRIO and MLX5E_NIC_PRIO. By doing
so, packets arriving during the window now fall through to the next
prio (at MLX5E_NIC_PRIO) instead of being dropped.
Fixes: 1c46d7409f30 ("net/mlx5e: Optimize promiscuous mode") Signed-off-by: Jianbo Liu <jianbol@nvidia.com> Reviewed-by: Mark Bloch <mbloch@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/1752155624-24095-4-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net/mlx5e: Fix race between DIM disable and net_dim()
There's a race between disabling DIM and NAPI callbacks using the dim
pointer on the RQ or SQ.
If NAPI checks the DIM state bit and sees it still set, it assumes
`rq->dim` or `sq->dim` is valid. But if DIM gets disabled right after
that check, the pointer might already be set to NULL, leading to a NULL
pointer dereference in net_dim().
Fix this by calling `synchronize_net()` before freeing the DIM context.
This ensures all in-progress NAPI callbacks are finished before the
pointer is cleared.
net/mlx5: Reset bw_share field when changing a node's parent
When changing a node's parent, its scheduling element is destroyed and
re-created with bw_share 0. However, the node's bw_share field was not
updated accordingly.
Set the node's bw_share to 0 after re-creation to keep the software
state in sync with the firmware configuration.
Fixes: 9c7bbf4c3304 ("net/mlx5: Add support for setting parent of nodes") Signed-off-by: Carolina Jubran <cjubran@nvidia.com> Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com> Reviewed-by: Dragos Tatulea <dtatulea@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Link: https://patch.msgid.link/1752155624-24095-2-git-send-email-tariqt@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Jakub Kicinski [Fri, 11 Jul 2025 14:07:56 +0000 (07:07 -0700)]
Merge tag 'linux-can-fixes-for-6.16-20250711' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can
Marc Kleine-Budde says:
====================
pull-request: can 2025-07-11
Sean Nyekjaer's patch targets the m_can driver and demotes the "msg
lost in rx" message to debug level to prevent flooding the kernel log
with error messages.
* tag 'linux-can-fixes-for-6.16-20250711' of git://git.kernel.org/pub/scm/linux/kernel/git/mkl/linux-can:
can: m_can: m_can_handle_lost_msg(): downgrade msg lost in rx message to debug level
====================
Hangbin Liu [Wed, 9 Jul 2025 09:12:44 +0000 (09:12 +0000)]
selftests: net: lib: fix shift count out of range
I got the following warning when writing other tests:
+ handle_test_result_pass 'bond 802.3ad' '(lacp_active off)'
+ local 'test_name=bond 802.3ad'
+ shift
+ local 'opt_str=(lacp_active off)'
+ shift
+ log_test_result 'bond 802.3ad' '(lacp_active off)' ' OK '
+ local 'test_name=bond 802.3ad'
+ shift
+ local 'opt_str=(lacp_active off)'
+ shift
+ local 'result= OK '
+ shift
+ local retmsg=
+ shift
/net/tools/testing/selftests/net/forwarding/../lib.sh: line 315: shift: shift count out of range
This happens because an extra shift is executed even after all arguments
have been consumed. Remove the last shift in log_test_result() to avoid
this warning.
When fixing IPv6 link-local address generation on GRE devices with
commit 3e6a0243ff00 ("gre: Fix again IPv6 link-local address
generation."), I accidentally broke the default IPv6 multicast route
creation on these GRE devices.
Fix that in patch 1, making the GRE specific code yet a bit closer to
the generic code used by most other network interface types.
Then extend the selftest in patch 2 to cover this case.
====================
selftests: Add IPv6 multicast route generation tests for GRE devices.
The previous patch fixes a bug that prevented the creation of the
default IPv6 multicast route (ff00::/8) for some GRE devices. Now let's
extend the GRE IPv6 selftests to cover this case.
Also, rename check_ipv6_ll_addr() to check_ipv6_device_config() and
adapt comments and script output to take into account the fact that
we're not limited to link-local address generation.
Use addrconf_add_dev() instead of ipv6_find_idev() in
addrconf_gre_config() so that we don't just get the inet6_dev, but also
install the default ff00::/8 multicast route.
Before commit 3e6a0243ff00 ("gre: Fix again IPv6 link-local address
generation."), the multicast route was created at the end of the
function by addrconf_add_mroute(). But this code path is now only taken
in one particular case (gre devices not bound to a local IP address and
in EUI64 mode). For all other cases, the function exits early and
addrconf_add_mroute() is not called anymore.
Using addrconf_add_dev() instead of ipv6_find_idev() in
addrconf_gre_config(), fixes the problem as it will create the default
multicast route for all gre devices. This also brings
addrconf_gre_config() a bit closer to the normal netdevice IPv6
configuration code (addrconf_dev_config()).
Cc: stable@vger.kernel.org Fixes: 3e6a0243ff00 ("gre: Fix again IPv6 link-local address generation.") Reported-by: Aiden Yang <ling@moedove.com> Closes: https://lore.kernel.org/netdev/CANR=AhRM7YHHXVxJ4DmrTNMeuEOY87K2mLmo9KMed1JMr20p6g@mail.gmail.com/ Reviewed-by: Gary Guo <gary@garyguo.net> Tested-by: Gary Guo <gary@garyguo.net> Signed-off-by: Guillaume Nault <gnault@redhat.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/027a923dcb550ad115e6d93ee8bb7d310378bd01.1752070620.git.gnault@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This patch series improves the reliability of the Microchip LAN88xx
PHYs, particularly in edge cases involving fixed link configurations or
forced speed modes.
Patch 1 assigns genphy_soft_reset() to the .soft_reset hook to ensure
that stale link partner advertisement (LPA) bits are properly cleared
during reconfiguration. Without this, outdated autonegotiation bits may
remain visible in some parallel detection cases.
Patch 2 restricts the 100 Mbps workaround (originally intended to handle
cable length switching) to only run when the link transitions to the
PHY_NOLINK state. This prevents repeated toggling that can confuse
autonegotiating link partners such as the Intel i350, leading to
unstable link cycles.
Both patches were tested on a LAN7850 (with integrated LAN88xx PHY)
against an Intel I350 NIC. The full test suite - autonegotiation, fixed
link, and parallel detection - passed successfully.
====================
net: phy: microchip: limit 100M workaround to link-down events on LAN88xx
Restrict the 100Mbit forced-mode workaround to link-down transitions
only, to prevent repeated link reset cycles in certain configurations.
The workaround was originally introduced to improve signal reliability
when switching cables between long and short distances. It temporarily
forces the PHY into 10 Mbps before returning to 100 Mbps.
However, when used with autonegotiating link partners (e.g., Intel i350),
executing this workaround on every link change can confuse the partner
and cause constant renegotiation loops. This results in repeated link
down/up transitions and the PHY never reaching a stable state.
Limit the workaround to only run during the PHY_NOLINK state. This ensures
it is triggered only once per link drop, avoiding disruptive toggling
while still preserving its intended effect.
Note: I am not able to reproduce the original issue that this workaround
addresses. I can only confirm that 100 Mbit mode works correctly in my
test setup. Based on code inspection, I assume the workaround aims to
reset some internal state machine or signal block by toggling speeds.
However, a PHY reset is already performed earlier in the function via
phy_init_hw(), which may achieve a similar effect. Without a reproducer,
I conservatively keep the workaround but restrict its conditions.
Fixes: e57cf3639c32 ("net: lan78xx: fix accessing the LAN7800's internal phy specific registers from the MAC driver") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/20250709130753.3994461-3-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: phy: microchip: Use genphy_soft_reset() to purge stale LPA bits
Enable .soft_reset for the LAN88xx PHY driver by assigning
genphy_soft_reset() to ensure that the phylib core performs a proper
soft reset during reconfiguration.
Previously, the driver left .soft_reset unimplemented, so calls to
phy_init_hw() (e.g., from lan88xx_link_change_notify()) did not fully
reset the PHY. As a result, stale contents in the Link Partner Ability
(LPA) register could persist, causing the PHY to incorrectly report
that the link partner advertised autonegotiation even when it did not.
Using genphy_soft_reset() guarantees a clean reset of the PHY and
corrects the false autoneg reporting in these scenarios.
Fixes: ccb989e4d1ef ("net: phy: microchip: Reset LAN88xx PHY to ensure clean link state on LAN7800/7850") Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de> Reviewed-by: Andrew Lunn <andrew@lunn.ch> Link: https://patch.msgid.link/20250709130753.3994461-2-o.rempel@pengutronix.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Mingming Cao [Wed, 9 Jul 2025 15:33:32 +0000 (08:33 -0700)]
ibmvnic: Fix hardcoded NUM_RX_STATS/NUM_TX_STATS with dynamic sizeof
The previous hardcoded definitions of NUM_RX_STATS and
NUM_TX_STATS were not updated when new fields were added
to the ibmvnic_{rx,tx}_queue_stats structures. Specifically,
commit 2ee73c54a615 ("ibmvnic: Add stat for tx direct vs tx
batched") added a fourth TX stat, but NUM_TX_STATS remained 3,
leading to a mismatch.
This patch replaces the static defines with dynamic sizeof-based
calculations to ensure the stat arrays are correctly sized.
This fixes incorrect indexing and prevents incomplete stat
reporting in tools like ethtool.
Fixes: 2ee73c54a615 ("ibmvnic: Add stat for tx direct vs tx batched") Signed-off-by: Mingming Cao <mmc@linux.ibm.com> Reviewed-by: Dave Marquardt <davemarq@linux.ibm.com> Reviewed-by: Haren Myneni <haren@linux.ibm.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250709153332.73892-1-mmc@linux.ibm.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Kito Xu [Wed, 9 Jul 2025 03:52:51 +0000 (03:52 +0000)]
net: appletalk: Fix device refcount leak in atrtr_create()
When updating an existing route entry in atrtr_create(), the old device
reference was not being released before assigning the new device,
leading to a device refcount leak. Fix this by calling dev_put() to
release the old device reference before holding the new one.
Merge tag 'net-6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from Bluetooth.
Current release - regressions:
- tcp: refine sk_rcvbuf increase for ooo packets
- bluetooth: fix attempting to send HCI_Disconnect to BIS handle
- rxrpc: fix over large frame size warning
- eth: bcmgenet: initialize u64 stats seq counter
Previous releases - regressions:
- tcp: correct signedness in skb remaining space calculation
- sched: abort __tc_modify_qdisc if parent class does not exist
- vsock: fix transport_{g2h,h2g} TOCTOU
- rxrpc: fix bug due to prealloc collision
- tipc: fix use-after-free in tipc_conn_close().
- bluetooth: fix not marking Broadcast Sink BIS as connected
- phy: qca808x: fix WoL issue by utilizing at8031_set_wol()
- eth: am65-cpsw-nuss: fix skb size by accounting for skb_shared_info
Previous releases - always broken:
- netlink: fix wraparounds of sk->sk_rmem_alloc.
- atm: fix infinite recursive call of clip_push().
- eth:
- stmmac: fix interrupt handling for level-triggered mode in DWC_XGMAC2
- rtsn: fix a null pointer dereference in rtsn_probe()"
* tag 'net-6.16-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (37 commits)
net/sched: sch_qfq: Fix null-deref in agg_dequeue
rxrpc: Fix oops due to non-existence of prealloc backlog struct
rxrpc: Fix bug due to prealloc collision
MAINTAINERS: remove myself as netronome maintainer
selftests/net: packetdrill: add tcp_ooo-before-and-after-accept.pkt
tcp: refine sk_rcvbuf increase for ooo packets
net/sched: Abort __tc_modify_qdisc if parent class does not exist
net: ethernet: ti: am65-cpsw-nuss: Fix skb size by accounting for skb_shared_info
net: thunderx: avoid direct MTU assignment after WRITE_ONCE()
selftests/tc-testing: Create test case for UAF scenario with DRR/NETEM/BLACKHOLE chain
atm: clip: Fix NULL pointer dereference in vcc_sendmsg()
atm: clip: Fix infinite recursive call of clip_push().
atm: clip: Fix memory leak of struct clip_vcc.
atm: clip: Fix potential null-ptr-deref in to_atmarpd().
net: phy: smsc: Fix link failure in forced mode with Auto-MDIX
net: phy: smsc: Force predictable MDI-X state on LAN87xx
net: phy: smsc: Fix Auto-MDIX configuration when disabled by strap
net: stmmac: Fix interrupt handling for level-triggered mode in DWC_XGMAC2
rxrpc: Fix over large frame size warning
net: airoha: Fix an error handling path in airoha_probe()
...
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull KVM fixes from Paolo Bonzini:
"Many patches, pretty much all of them small, that accumulated while I
was on vacation.
ARM:
- Remove the last leftovers of the ill-fated FPSIMD host state
mapping at EL2 stage-1
- Fix unexpected advertisement to the guest of unimplemented S2 base
granule sizes
- Gracefully fail initialising pKVM if the interrupt controller isn't
GICv3
- Also gracefully fail initialising pKVM if the carveout allocation
fails
- Fix the computing of the minimum MMIO range required for the host
on stage-2 fault
- Fix the generation of the GICv3 Maintenance Interrupt in nested
mode
x86:
- Reject SEV{-ES} intra-host migration if one or more vCPUs are
actively being created, so as not to create a non-SEV{-ES} vCPU in
an SEV{-ES} VM
- Use a pre-allocated, per-vCPU buffer for handling de-sparsification
of vCPU masks in Hyper-V hypercalls; fixes a "stack frame too
large" issue
- Allow out-of-range/invalid Xen event channel ports when configuring
IRQ routing, to avoid dictating a specific ioctl() ordering to
userspace
- Conditionally reschedule when setting memory attributes to avoid
soft lockups when userspace converts huge swaths of memory to/from
private
- Add back MWAIT as a required feature for the MONITOR/MWAIT selftest
- Add a missing field in struct sev_data_snp_launch_start that
resulted in the guest-visible workarounds field being filled at the
wrong offset
- Skip non-canonical address when processing Hyper-V PV TLB flushes
to avoid VM-Fail on INVVPID
- Advertise supported TDX TDVMCALLs to userspace
- Pass SetupEventNotifyInterrupt arguments to userspace
- Fix TSC frequency underflow"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
KVM: x86: avoid underflow when scaling TSC frequency
KVM: arm64: Remove kvm_arch_vcpu_run_map_fp()
KVM: arm64: Fix handling of FEAT_GTG for unimplemented granule sizes
KVM: arm64: Don't free hyp pages with pKVM on GICv2
KVM: arm64: Fix error path in init_hyp_mode()
KVM: arm64: Adjust range correctly during host stage-2 faults
KVM: arm64: nv: Fix MI line level calculation in vgic_v3_nested_update_mi()
KVM: x86/hyper-v: Skip non-canonical addresses during PV TLB flush
KVM: SVM: Add missing member in SNP_LAUNCH_START command structure
Documentation: KVM: Fix unexpected unindent warnings
KVM: selftests: Add back the missing check of MONITOR/MWAIT availability
KVM: Allow CPU to reschedule while setting per-page memory attributes
KVM: x86/xen: Allow 'out of range' event channel ports in IRQ routing table.
KVM: x86/hyper-v: Use preallocated per-vCPU buffer for de-sparsified vCPU masks
KVM: SVM: Initialize vmsa_pa in VMCB to INVALID_PAGE if VMSA page is NULL
KVM: SVM: Reject SEV{-ES} intra host migration if vCPU creation is in-flight
KVM: TDX: Report supported optional TDVMCALLs in TDX capabilities
KVM: TDX: Exit to userspace for SetupEventNotifyInterrupt
wifi: mac80211: add the virtual monitor after reconfig complete
In reconfig we add the virtual monitor in 2 cases:
1. If we are resuming (it was deleted on suspend)
2. If it was added after an error but before the reconfig
(due to the last non-monitor interface removal).
In the second case, the removal of the non-monitor interface will succeed
but the addition of the virtual monitor will fail, so we add it in the
reconfig.
The problem is that we mislead the driver to think that this is an existing
interface that is getting re-added - while it is actually a completely new
interface from the drivers' point of view.
Some drivers act differently when a interface is re-added. For example, it
might not initialize things because they were already initialized.
Such drivers will - in this case - be left with a partialy initialized vif.
To fix it, add the virtual monitor after reconfig_complete, so the
driver will know that this is a completely new interface.
This is currently not initialized for a virtual monitor, leading to a
NULL pointer dereference when - for example - iterating over all the
keys of all the vifs.
Xiang Mei [Sat, 5 Jul 2025 21:21:43 +0000 (14:21 -0700)]
net/sched: sch_qfq: Fix null-deref in agg_dequeue
To prevent a potential crash in agg_dequeue (net/sched/sch_qfq.c)
when cl->qdisc->ops->peek(cl->qdisc) returns NULL, we check the return
value before using it, similar to the existing approach in sch_hfsc.c.
To avoid code duplication, the following changes are made:
1. Changed qdisc_warn_nonwc(include/net/pkt_sched.h) into a static
inline function.
2. Moved qdisc_peek_len from net/sched/sch_hfsc.c to
include/net/pkt_sched.h so that sch_qfq can reuse it.
3. Applied qdisc_peek_len in agg_dequeue to avoid crashing.
David Howells [Tue, 8 Jul 2025 21:15:04 +0000 (22:15 +0100)]
rxrpc: Fix oops due to non-existence of prealloc backlog struct
If an AF_RXRPC service socket is opened and bound, but calls are
preallocated, then rxrpc_alloc_incoming_call() will oops because the
rxrpc_backlog struct doesn't get allocated until the first preallocation is
made.
Fix this by returning NULL from rxrpc_alloc_incoming_call() if there is no
backlog struct. This will cause the incoming call to be aborted.
Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com> Suggested-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com> Signed-off-by: David Howells <dhowells@redhat.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Willy Tarreau <w@1wt.eu>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250708211506.2699012-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
David Howells [Tue, 8 Jul 2025 21:15:03 +0000 (22:15 +0100)]
rxrpc: Fix bug due to prealloc collision
When userspace is using AF_RXRPC to provide a server, it has to preallocate
incoming calls and assign to them call IDs that will be used to thread
related recvmsg() and sendmsg() together. The preallocated call IDs will
automatically be attached to calls as they come in until the pool is empty.
To the kernel, the call IDs are just arbitrary numbers, but userspace can
use the call ID to hold a pointer to prepared structs. In any case, the
user isn't permitted to create two calls with the same call ID (call IDs
become available again when the call ends) and EBADSLT should result from
sendmsg() if an attempt is made to preallocate a call with an in-use call
ID.
However, the cleanup in the error handling will trigger both assertions in
rxrpc_cleanup_call() because the call isn't marked complete and isn't
marked as having been released.
Fix this by setting the call state in rxrpc_service_prealloc_one() and then
marking it as being released before calling the cleanup function.
Fixes: 00e907127e6f ("rxrpc: Preallocate peers, conns and calls for incoming service requests") Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com> Signed-off-by: David Howells <dhowells@redhat.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org Link: https://patch.msgid.link/20250708211506.2699012-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Louis Peens [Tue, 8 Jul 2025 08:20:51 +0000 (10:20 +0200)]
MAINTAINERS: remove myself as netronome maintainer
I am moving on from Corigine to different things, for the moment
slightly removed from kernel development. Right now there is nobody I
can in good conscience recommend to take over the maintainer role, but
there are still people available for review, so put the driver state to
'Odd Fixes'.
Additionally add Simon Horman as reviewer - thanks Simon.
Signed-off-by: Louis Peens <louis.peens@corigine.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Victor Nogueira [Mon, 7 Jul 2025 21:08:01 +0000 (18:08 -0300)]
net/sched: Abort __tc_modify_qdisc if parent class does not exist
Lion's patch [1] revealed an ancient bug in the qdisc API.
Whenever a user creates/modifies a qdisc specifying as a parent another
qdisc, the qdisc API will, during grafting, detect that the user is
not trying to attach to a class and reject. However grafting is
performed after qdisc_create (and thus the qdiscs' init callback) is
executed. In qdiscs that eventually call qdisc_tree_reduce_backlog
during init or change (such as fq, hhf, choke, etc), an issue
arises. For example, executing the following commands:
sudo tc qdisc add dev lo root handle a: htb default 2
sudo tc qdisc add dev lo parent a: handle beef fq
Qdiscs such as fq, hhf, choke, etc unconditionally invoke
qdisc_tree_reduce_backlog() in their control path init() or change() which
then causes a failure to find the child class; however, that does not stop
the unconditional invocation of the assumed child qdisc's qlen_notify with
a null class. All these qdiscs make the assumption that class is non-null.
The solution is ensure that qdisc_leaf() which looks up the parent
class, and is invoked prior to qdisc_create(), should return failure on
not finding the class.
In this patch, we leverage qdisc_leaf to return ERR_PTRs whenever the
parentid doesn't correspond to a class, so that we can detect it
earlier on and abort before qdisc_create is called.