<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/include/net, branch v7.1-rc3</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Bluetooth: l2cap: defer conn param update to avoid conn-&gt;lock/hdev-&gt;lock inversion</title>
<updated>2026-05-06T20:20:51+00:00</updated>
<author>
<name>Mikhail Gavrilov</name>
<email>mikhail.v.gavrilov@gmail.com</email>
</author>
<published>2026-04-14T21:52:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=91b5a598b5285da794b72619f31777b62dd336f8'/>
<id>91b5a598b5285da794b72619f31777b62dd336f8</id>
<content type='text'>
When a BLE peripheral sends an L2CAP Connection Parameter Update Request
the processing path is:

  process_pending_rx()          [takes conn-&gt;lock]
    l2cap_le_sig_channel()
      l2cap_conn_param_update_req()
        hci_le_conn_update()    [takes hdev-&gt;lock]

Meanwhile other code paths take the locks in the opposite order:

  l2cap_chan_connect()          [takes hdev-&gt;lock]
    ...
      mutex_lock(&amp;conn-&gt;lock)

  l2cap_conn_ready()            [hdev-&gt;lock via hci_cb_list_lock]
    ...
      mutex_lock(&amp;conn-&gt;lock)

This is a classic AB/BA deadlock which lockdep reports as a circular
locking dependency when connecting a BLE MIDI keyboard (Carry-On FC-49).

Fix this by making hci_le_conn_update() defer the HCI command through
hci_cmd_sync_queue() so it no longer needs to take hdev-&gt;lock in the
caller context.  The sync callback uses __hci_cmd_sync_status_sk() to
wait for the HCI_EV_LE_CONN_UPDATE_COMPLETE event, then updates the
stored connection parameters (hci_conn_params) and notifies userspace
(mgmt_new_conn_param) only after the controller has confirmed the update.

A reference on hci_conn is held via hci_conn_get()/hci_conn_put() for
the lifetime of the queued work to prevent use-after-free, and
hci_conn_valid() is checked before proceeding in case the connection was
removed while the work was pending.  The hci_dev_lock is held across
hci_conn_valid() and all conn field accesses to prevent a concurrent
disconnect from invalidating the connection mid-use.

Fixes: f044eb0524a0 ("Bluetooth: Store latency and supervision timeout in connection params")
Signed-off-by: Mikhail Gavrilov &lt;mikhail.v.gavrilov@gmail.com&gt;
Reviewed-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When a BLE peripheral sends an L2CAP Connection Parameter Update Request
the processing path is:

  process_pending_rx()          [takes conn-&gt;lock]
    l2cap_le_sig_channel()
      l2cap_conn_param_update_req()
        hci_le_conn_update()    [takes hdev-&gt;lock]

Meanwhile other code paths take the locks in the opposite order:

  l2cap_chan_connect()          [takes hdev-&gt;lock]
    ...
      mutex_lock(&amp;conn-&gt;lock)

  l2cap_conn_ready()            [hdev-&gt;lock via hci_cb_list_lock]
    ...
      mutex_lock(&amp;conn-&gt;lock)

This is a classic AB/BA deadlock which lockdep reports as a circular
locking dependency when connecting a BLE MIDI keyboard (Carry-On FC-49).

Fix this by making hci_le_conn_update() defer the HCI command through
hci_cmd_sync_queue() so it no longer needs to take hdev-&gt;lock in the
caller context.  The sync callback uses __hci_cmd_sync_status_sk() to
wait for the HCI_EV_LE_CONN_UPDATE_COMPLETE event, then updates the
stored connection parameters (hci_conn_params) and notifies userspace
(mgmt_new_conn_param) only after the controller has confirmed the update.

A reference on hci_conn is held via hci_conn_get()/hci_conn_put() for
the lifetime of the queued work to prevent use-after-free, and
hci_conn_valid() is checked before proceeding in case the connection was
removed while the work was pending.  The hci_dev_lock is held across
hci_conn_valid() and all conn field accesses to prevent a concurrent
disconnect from invalidating the connection mid-use.

Fixes: f044eb0524a0 ("Bluetooth: Store latency and supervision timeout in connection params")
Signed-off-by: Mikhail Gavrilov &lt;mikhail.v.gavrilov@gmail.com&gt;
Reviewed-by: Paul Menzel &lt;pmenzel@molgen.mpg.de&gt;
Signed-off-by: Luiz Augusto von Dentz &lt;luiz.von.dentz@intel.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'nf-26-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf</title>
<updated>2026-05-06T00:55:25+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-05-06T00:55:25+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=40aa9fcea0721f5b885eec2fb9aa526145e83797'/>
<id>40aa9fcea0721f5b885eec2fb9aa526145e83797</id>
<content type='text'>
Pablo Neira Ayuso says:

====================
IPVS fixes for net

The following batch contains IPVS fixes for net to address issues
from the latest net-next pull request.

Julian Anastasov made the following summary:

1-3) Fixes for the recently added resizable hash tables

4) dest from trash can be leaked if ip_vs_start_estimator() fails

5) fixed races and locking for the estimation kthreads

6) fix for wrong roundup_pow_of_two() usage in the resizable hash
   tables

7-8) v2 of the changes from Waiman Long to properly guard against
  the housekeeping_cpumask() updates:

  https://lore.kernel.org/netfilter-devel/20260331165015.2777765-1-longman@redhat.com/

  I added missing Fixes tag. The original description:

  Since commit 041ee6f3727a ("kthread: Rely on HK_TYPE_DOMAIN for preferred
  affinity management"), the HK_TYPE_KTHREAD housekeeping cpumask may no
  longer be correct in showing the actual CPU affinity of kthreads that
  have no predefined CPU affinity. As the ipvs networking code is still
  using HK_TYPE_KTHREAD, we need to make HK_TYPE_KTHREAD reflect the
  reality.

  This patch series makes HK_TYPE_KTHREAD an alias of HK_TYPE_DOMAIN
  and uses RCU to protect access to the HK_TYPE_KTHREAD housekeeping
  cpumask.

Julian plans to post a nf-next patch to limit the connections by using
"conn_max" sysctl. With Simon Horman, they agreed that this is an old
problem that we do not have a limit of connections and it is not a
stopper for this patchset.

* tag 'nf-26-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  sched/isolation: Make HK_TYPE_KTHREAD an alias of HK_TYPE_DOMAIN
  ipvs: Guard access of HK_TYPE_KTHREAD cpumask with RCU
  ipvs: fix shift-out-of-bounds in ip_vs_rht_desired_size
  ipvs: fix races around est_mutex and est_cpulist
  ipvs: do not leak dest after get from dest trash
  ipvs: fix the spin_lock usage for RT build
  ipvs: fix races around the conn_lfactor and svc_lfactor sysctl vars
  ipvs: fixes for the new ip_vs_status info
====================

Link: https://patch.msgid.link/20260505001648.360569-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

====================
IPVS fixes for net

The following batch contains IPVS fixes for net to address issues
from the latest net-next pull request.

Julian Anastasov made the following summary:

1-3) Fixes for the recently added resizable hash tables

4) dest from trash can be leaked if ip_vs_start_estimator() fails

5) fixed races and locking for the estimation kthreads

6) fix for wrong roundup_pow_of_two() usage in the resizable hash
   tables

7-8) v2 of the changes from Waiman Long to properly guard against
  the housekeeping_cpumask() updates:

  https://lore.kernel.org/netfilter-devel/20260331165015.2777765-1-longman@redhat.com/

  I added missing Fixes tag. The original description:

  Since commit 041ee6f3727a ("kthread: Rely on HK_TYPE_DOMAIN for preferred
  affinity management"), the HK_TYPE_KTHREAD housekeeping cpumask may no
  longer be correct in showing the actual CPU affinity of kthreads that
  have no predefined CPU affinity. As the ipvs networking code is still
  using HK_TYPE_KTHREAD, we need to make HK_TYPE_KTHREAD reflect the
  reality.

  This patch series makes HK_TYPE_KTHREAD an alias of HK_TYPE_DOMAIN
  and uses RCU to protect access to the HK_TYPE_KTHREAD housekeeping
  cpumask.

Julian plans to post a nf-next patch to limit the connections by using
"conn_max" sysctl. With Simon Horman, they agreed that this is an old
problem that we do not have a limit of connections and it is not a
stopper for this patchset.

* tag 'nf-26-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  sched/isolation: Make HK_TYPE_KTHREAD an alias of HK_TYPE_DOMAIN
  ipvs: Guard access of HK_TYPE_KTHREAD cpumask with RCU
  ipvs: fix shift-out-of-bounds in ip_vs_rht_desired_size
  ipvs: fix races around est_mutex and est_cpulist
  ipvs: do not leak dest after get from dest trash
  ipvs: fix the spin_lock usage for RT build
  ipvs: fix races around the conn_lfactor and svc_lfactor sysctl vars
  ipvs: fixes for the new ip_vs_status info
====================

Link: https://patch.msgid.link/20260505001648.360569-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: mana: Fix crash from unvalidated SHM offset read from BAR0 during FLR</title>
<updated>2026-05-05T13:43:08+00:00</updated>
<author>
<name>Dipayaan Roy</name>
<email>dipayanroy@linux.microsoft.com</email>
</author>
<published>2026-05-01T02:47:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=95084f1883a760e0d4290698346759d58e2b944a'/>
<id>95084f1883a760e0d4290698346759d58e2b944a</id>
<content type='text'>
During Function Level Reset recovery, the MANA driver reads
hardware BAR0 registers that may temporarily contain garbage values.
The SHM (Shared Memory) offset read from GDMA_REG_SHM_OFFSET is used
to compute gc-&gt;shm_base, which is later dereferenced via readl() in
mana_smc_poll_register(). If the hardware returns an unaligned or
out-of-range value, the driver must not blindly use it, as this would
propagate the hardware error into a kernel crash.

The following crash was observed on an arm64 Hyper-V guest running
kernel 6.17.0-3013-azure during VF reset recovery triggered by HWC
timeout.

[13291.785274] Unable to handle kernel paging request at virtual address ffff8000a200001b
[13291.785311] Mem abort info:
[13291.785332]   ESR = 0x0000000096000021
[13291.785343]   EC = 0x25: DABT (current EL), IL = 32 bits
[13291.785355]   SET = 0, FnV = 0
[13291.785363]   EA = 0, S1PTW = 0
[13291.785372]   FSC = 0x21: alignment fault
[13291.785382] Data abort info:
[13291.785391]   ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000
[13291.785404]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[13291.785412]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[13291.785421] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000014df3a1000
[13291.785432] [ffff8000a200001b] pgd=1000000100438403, p4d=1000000100438403, pud=1000000100439403, pmd=0068000fc2000711
[13291.785703] Internal error: Oops: 0000000096000021 [#1]  SMP
[13291.830975] Modules linked in: tls qrtr mana_ib ib_uverbs ib_core xt_owner xt_tcpudp xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables cfg80211 8021q garp mrp stp llc binfmt_misc joydev serio_raw nls_iso8859_1 hid_generic aes_ce_blk aes_ce_cipher polyval_ce ghash_ce sm4_ce_gcm sm4_ce_ccm sm4_ce sm4_ce_cipher hid_hyperv sm4 sm3_ce sha3_ce hv_netvsc hid vmgenid hyperv_keyboard hyperv_drm sch_fq_codel nvme_fabrics efi_pstore dm_multipath nfnetlink vsock_loopback vmw_vsock_virtio_transport_common hv_sock vmw_vsock_vmci_transport vmw_vmci vsock dmi_sysfs ip_tables x_tables autofs4
[13291.862630] CPU: 122 UID: 0 PID: 61796 Comm: kworker/122:2 Tainted: G        W           6.17.0-3013-azure #13-Ubuntu VOLUNTARY
[13291.869902] Tainted: [W]=WARN
[13291.871901] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 01/08/2026
[13291.878086] Workqueue: events mana_serv_func
[13291.880718] pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
[13291.884835] pc : mana_smc_poll_register+0x48/0xb0
[13291.887902] lr : mana_smc_setup_hwc+0x70/0x1c0
[13291.890493] sp : ffff8000ab79bbb0
[13291.892364] x29: ffff8000ab79bbb0 x28: ffff00410c8b5900 x27: ffff00410d630680
[13291.896252] x26: ffff004171f9fd80 x25: 000000016ed55000 x24: 000000017f37e000
[13291.899990] x23: 0000000000000000 x22: 000000016ed55000 x21: 0000000000000000
[13291.904497] x20: ffff8000a200001b x19: 0000000000004e20 x18: ffff8000a6183050
[13291.908308] x17: 0000000000000000 x16: 0000000000000000 x15: 000000000000000a
[13291.912542] x14: 0000000000000004 x13: 0000000000000000 x12: 0000000000000000
[13291.916298] x11: 0000000000000000 x10: 0000000000000001 x9 : ffffc45006af1bd8
[13291.920945] x8 : ffff000151129000 x7 : 0000000000000000 x6 : 0000000000000000
[13291.925293] x5 : 000000015f214000 x4 : 000000017217a000 x3 : 000000016ed50000
[13291.930436] x2 : 000000016ed55000 x1 : 0000000000000000 x0 : ffff8000a1ffffff
[13291.934342] Call trace:
[13291.935736]  mana_smc_poll_register+0x48/0xb0 (P)
[13291.938611]  mana_smc_setup_hwc+0x70/0x1c0
[13291.941113]  mana_hwc_create_channel+0x1a0/0x3a0
[13291.944283]  mana_gd_setup+0x16c/0x398
[13291.946584]  mana_gd_resume+0x24/0x70
[13291.948917]  mana_do_service+0x13c/0x1d0
[13291.951583]  mana_serv_func+0x34/0x68
[13291.953732]  process_one_work+0x168/0x3d0
[13291.956745]  worker_thread+0x2ac/0x480
[13291.959104]  kthread+0xf8/0x110
[13291.961026]  ret_from_fork+0x10/0x20
[13291.963560] Code: d2807d00 9417c551 71000673 54000220 (b9400281)
[13291.967299] ---[ end trace 0000000000000000 ]---

Disassembly of mana_smc_poll_register() around the crash site:

Disassembly of section .text:

00000000000047c8 &lt;mana_smc_poll_register&gt;:
    47c8: d503201f        nop
    47cc: d503201f        nop
    47d0: d503233f        paciasp
    47d4: f800865e        str     x30, [x18], #8
    47d8: a9bd7bfd        stp     x29, x30, [sp, #-48]!
    47dc: 910003fd        mov     x29, sp
    47e0: a90153f3        stp     x19, x20, [sp, #16]
    47e4: 91007014        add     x20, x0, #0x1c
    47e8: 5289c413        mov     w19, #0x4e20
    47ec: f90013f5        str     x21, [sp, #32]
    47f0: 12001c35        and     w21, w1, #0xff
    47f4: 14000008        b       4814 &lt;mana_smc_poll_register+0x4c&gt;
    47f8: 36f801e1  tbz  w1, #31, 4834 &lt;mana_smc_poll_register+0x6c&gt;
    47fc: 52800042        mov     w2, #0x2
    4800: d280fa01        mov     x1, #0x7d0
    4804: d2807d00        mov     x0, #0x3e8
    4808: 94000000        bl      0 &lt;usleep_range_state&gt;
    480c: 71000673        subs    w19, w19, #0x1
    4810: 54000200        b.eq    4850 &lt;mana_smc_poll_register+0x88&gt;
    4814: b9400281      ldr   w1, [x20] &lt;-- **** CRASHED HERE *****
    4818: d50331bf        dmb     oshld
    481c: 2a0103e2        mov     w2, w1
    ...

From the crash signature x20 = ffff8000a200001b, this address
ends in 0x1b which is not 4-byte aligned, so the 'ldr w1, [x20]'
instruction (readl) triggers the arm64 alignment fault (FSC = 0x21).

The root cause is in mana_gd_init_vf_regs(), which computes:

  gc-&gt;shm_base = gc-&gt;bar0_va + mana_gd_r64(gc, GDMA_REG_SHM_OFFSET);

The offset is used without any validation.  The same problem exists
in mana_gd_init_pf_regs() for sriov_base_off and sriov_shm_off.

Fix this by validating all offsets before use:

- VF: check shm_off is within BAR0, properly aligned to 4 bytes
  (readl requirement), and leaves room for the full 256-bit
  (32-byte) SMC aperture.

- PF: check sriov_base_off is within BAR0, aligned to 8 bytes
  (readq requirement), and leaves room to safely read the
  sriov_shm_off register at sriov_base_off + GDMA_PF_REG_SHM_OFF.
  Then check sriov_shm_off leaves room for the full SMC aperture.
  All arithmetic uses subtraction rather than addition to avoid
  integer overflow on garbage values.

Define SMC_APERTURE_SIZE (32 bytes, derived from the 256-bit aperture
width)

Return -EPROTO on invalid values.  The existing recovery path in
mana_serv_reset() already handles -EPROTO by falling through to PCI
device rescan, giving the hardware another chance to present valid
register values after reset.

Fixes: 9bf66036d686 ("net: mana: Handle hardware recovery events when probing the device")
Signed-off-by: Dipayaan Roy &lt;dipayanroy@linux.microsoft.com&gt;
Link: https://patch.msgid.link/afQUMClyjmBVfD+u@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
During Function Level Reset recovery, the MANA driver reads
hardware BAR0 registers that may temporarily contain garbage values.
The SHM (Shared Memory) offset read from GDMA_REG_SHM_OFFSET is used
to compute gc-&gt;shm_base, which is later dereferenced via readl() in
mana_smc_poll_register(). If the hardware returns an unaligned or
out-of-range value, the driver must not blindly use it, as this would
propagate the hardware error into a kernel crash.

The following crash was observed on an arm64 Hyper-V guest running
kernel 6.17.0-3013-azure during VF reset recovery triggered by HWC
timeout.

[13291.785274] Unable to handle kernel paging request at virtual address ffff8000a200001b
[13291.785311] Mem abort info:
[13291.785332]   ESR = 0x0000000096000021
[13291.785343]   EC = 0x25: DABT (current EL), IL = 32 bits
[13291.785355]   SET = 0, FnV = 0
[13291.785363]   EA = 0, S1PTW = 0
[13291.785372]   FSC = 0x21: alignment fault
[13291.785382] Data abort info:
[13291.785391]   ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000
[13291.785404]   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
[13291.785412]   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
[13291.785421] swapper pgtable: 4k pages, 48-bit VAs, pgdp=00000014df3a1000
[13291.785432] [ffff8000a200001b] pgd=1000000100438403, p4d=1000000100438403, pud=1000000100439403, pmd=0068000fc2000711
[13291.785703] Internal error: Oops: 0000000096000021 [#1]  SMP
[13291.830975] Modules linked in: tls qrtr mana_ib ib_uverbs ib_core xt_owner xt_tcpudp xt_conntrack nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nft_compat nf_tables cfg80211 8021q garp mrp stp llc binfmt_misc joydev serio_raw nls_iso8859_1 hid_generic aes_ce_blk aes_ce_cipher polyval_ce ghash_ce sm4_ce_gcm sm4_ce_ccm sm4_ce sm4_ce_cipher hid_hyperv sm4 sm3_ce sha3_ce hv_netvsc hid vmgenid hyperv_keyboard hyperv_drm sch_fq_codel nvme_fabrics efi_pstore dm_multipath nfnetlink vsock_loopback vmw_vsock_virtio_transport_common hv_sock vmw_vsock_vmci_transport vmw_vmci vsock dmi_sysfs ip_tables x_tables autofs4
[13291.862630] CPU: 122 UID: 0 PID: 61796 Comm: kworker/122:2 Tainted: G        W           6.17.0-3013-azure #13-Ubuntu VOLUNTARY
[13291.869902] Tainted: [W]=WARN
[13291.871901] Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS Hyper-V UEFI Release v4.1 01/08/2026
[13291.878086] Workqueue: events mana_serv_func
[13291.880718] pstate: 62400005 (nZCv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=--)
[13291.884835] pc : mana_smc_poll_register+0x48/0xb0
[13291.887902] lr : mana_smc_setup_hwc+0x70/0x1c0
[13291.890493] sp : ffff8000ab79bbb0
[13291.892364] x29: ffff8000ab79bbb0 x28: ffff00410c8b5900 x27: ffff00410d630680
[13291.896252] x26: ffff004171f9fd80 x25: 000000016ed55000 x24: 000000017f37e000
[13291.899990] x23: 0000000000000000 x22: 000000016ed55000 x21: 0000000000000000
[13291.904497] x20: ffff8000a200001b x19: 0000000000004e20 x18: ffff8000a6183050
[13291.908308] x17: 0000000000000000 x16: 0000000000000000 x15: 000000000000000a
[13291.912542] x14: 0000000000000004 x13: 0000000000000000 x12: 0000000000000000
[13291.916298] x11: 0000000000000000 x10: 0000000000000001 x9 : ffffc45006af1bd8
[13291.920945] x8 : ffff000151129000 x7 : 0000000000000000 x6 : 0000000000000000
[13291.925293] x5 : 000000015f214000 x4 : 000000017217a000 x3 : 000000016ed50000
[13291.930436] x2 : 000000016ed55000 x1 : 0000000000000000 x0 : ffff8000a1ffffff
[13291.934342] Call trace:
[13291.935736]  mana_smc_poll_register+0x48/0xb0 (P)
[13291.938611]  mana_smc_setup_hwc+0x70/0x1c0
[13291.941113]  mana_hwc_create_channel+0x1a0/0x3a0
[13291.944283]  mana_gd_setup+0x16c/0x398
[13291.946584]  mana_gd_resume+0x24/0x70
[13291.948917]  mana_do_service+0x13c/0x1d0
[13291.951583]  mana_serv_func+0x34/0x68
[13291.953732]  process_one_work+0x168/0x3d0
[13291.956745]  worker_thread+0x2ac/0x480
[13291.959104]  kthread+0xf8/0x110
[13291.961026]  ret_from_fork+0x10/0x20
[13291.963560] Code: d2807d00 9417c551 71000673 54000220 (b9400281)
[13291.967299] ---[ end trace 0000000000000000 ]---

Disassembly of mana_smc_poll_register() around the crash site:

Disassembly of section .text:

00000000000047c8 &lt;mana_smc_poll_register&gt;:
    47c8: d503201f        nop
    47cc: d503201f        nop
    47d0: d503233f        paciasp
    47d4: f800865e        str     x30, [x18], #8
    47d8: a9bd7bfd        stp     x29, x30, [sp, #-48]!
    47dc: 910003fd        mov     x29, sp
    47e0: a90153f3        stp     x19, x20, [sp, #16]
    47e4: 91007014        add     x20, x0, #0x1c
    47e8: 5289c413        mov     w19, #0x4e20
    47ec: f90013f5        str     x21, [sp, #32]
    47f0: 12001c35        and     w21, w1, #0xff
    47f4: 14000008        b       4814 &lt;mana_smc_poll_register+0x4c&gt;
    47f8: 36f801e1  tbz  w1, #31, 4834 &lt;mana_smc_poll_register+0x6c&gt;
    47fc: 52800042        mov     w2, #0x2
    4800: d280fa01        mov     x1, #0x7d0
    4804: d2807d00        mov     x0, #0x3e8
    4808: 94000000        bl      0 &lt;usleep_range_state&gt;
    480c: 71000673        subs    w19, w19, #0x1
    4810: 54000200        b.eq    4850 &lt;mana_smc_poll_register+0x88&gt;
    4814: b9400281      ldr   w1, [x20] &lt;-- **** CRASHED HERE *****
    4818: d50331bf        dmb     oshld
    481c: 2a0103e2        mov     w2, w1
    ...

From the crash signature x20 = ffff8000a200001b, this address
ends in 0x1b which is not 4-byte aligned, so the 'ldr w1, [x20]'
instruction (readl) triggers the arm64 alignment fault (FSC = 0x21).

The root cause is in mana_gd_init_vf_regs(), which computes:

  gc-&gt;shm_base = gc-&gt;bar0_va + mana_gd_r64(gc, GDMA_REG_SHM_OFFSET);

The offset is used without any validation.  The same problem exists
in mana_gd_init_pf_regs() for sriov_base_off and sriov_shm_off.

Fix this by validating all offsets before use:

- VF: check shm_off is within BAR0, properly aligned to 4 bytes
  (readl requirement), and leaves room for the full 256-bit
  (32-byte) SMC aperture.

- PF: check sriov_base_off is within BAR0, aligned to 8 bytes
  (readq requirement), and leaves room to safely read the
  sriov_shm_off register at sriov_base_off + GDMA_PF_REG_SHM_OFF.
  Then check sriov_shm_off leaves room for the full SMC aperture.
  All arithmetic uses subtraction rather than addition to avoid
  integer overflow on garbage values.

Define SMC_APERTURE_SIZE (32 bytes, derived from the 256-bit aperture
width)

Return -EPROTO on invalid values.  The existing recovery path in
mana_serv_reset() already handles -EPROTO by falling through to PCI
device rescan, giving the hardware another chance to present valid
register values after reset.

Fixes: 9bf66036d686 ("net: mana: Handle hardware recovery events when probing the device")
Signed-off-by: Dipayaan Roy &lt;dipayanroy@linux.microsoft.com&gt;
Link: https://patch.msgid.link/afQUMClyjmBVfD+u@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net
Signed-off-by: Paolo Abeni &lt;pabeni@redhat.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipmr: Add __rcu to netns_ipv4.mrt.</title>
<updated>2026-05-05T02:26:13+00:00</updated>
<author>
<name>Kuniyuki Iwashima</name>
<email>kuniyu@google.com</email>
</author>
<published>2026-05-02T18:07:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=a6039776c7994dd0b9a4acce23a3f897d1688cbf'/>
<id>a6039776c7994dd0b9a4acce23a3f897d1688cbf</id>
<content type='text'>
kernel test robot reported this Sparse warning:

  $ make C=1 net/ipv4/ipmr.o
  net/ipv4/ipmr.c:312:24: error: incompatible types in comparison expression (different address spaces):
  net/ipv4/ipmr.c:312:24:    struct mr_table [noderef] __rcu *
  net/ipv4/ipmr.c:312:24:    struct mr_table *

Let's add __rcu annotation to netns_ipv4.mrt.

Fixes: b3b6babf4751 ("ipmr: Free mr_table after RCU grace period.")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202605030032.glNApko7-lkp@intel.com/
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260502180755.359554-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
kernel test robot reported this Sparse warning:

  $ make C=1 net/ipv4/ipmr.o
  net/ipv4/ipmr.c:312:24: error: incompatible types in comparison expression (different address spaces):
  net/ipv4/ipmr.c:312:24:    struct mr_table [noderef] __rcu *
  net/ipv4/ipmr.c:312:24:    struct mr_table *

Let's add __rcu annotation to netns_ipv4.mrt.

Fixes: b3b6babf4751 ("ipmr: Free mr_table after RCU grace period.")
Reported-by: kernel test robot &lt;lkp@intel.com&gt;
Closes: https://lore.kernel.org/oe-kbuild-all/202605030032.glNApko7-lkp@intel.com/
Signed-off-by: Kuniyuki Iwashima &lt;kuniyu@google.com&gt;
Link: https://patch.msgid.link/20260502180755.359554-1-kuniyu@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: Guard access of HK_TYPE_KTHREAD cpumask with RCU</title>
<updated>2026-05-04T23:52:55+00:00</updated>
<author>
<name>Waiman Long</name>
<email>longman@redhat.com</email>
</author>
<published>2026-04-30T07:44:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=aa6065206987278291c09d0c6aebed687114c925'/>
<id>aa6065206987278291c09d0c6aebed687114c925</id>
<content type='text'>
The ip_vs_ctl.c file and the associated ip_vs.h file are the only places
in the kernel where HK_TYPE_KTHREAD cpumask is being retrieved and used.
Now that HK_TYPE_KTHREAD/HK_TYPE_DOMAIN cpumask can be changed at run
time. We need to use RCU to guard access to this cpumask to avoid a
potential UAF problem as the returned cpumask may be freed before it
is being used.

We can replace HK_TYPE_KTHREAD by HK_TYPE_DOMAIN as they are aliases
of each other, but keeping the HK_TYPE_KTHREAD name can highlight the
fact that it is the kthread initiated by ipvs that is being controlled.

Fixes: 03ff73510169 ("cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset")
Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The ip_vs_ctl.c file and the associated ip_vs.h file are the only places
in the kernel where HK_TYPE_KTHREAD cpumask is being retrieved and used.
Now that HK_TYPE_KTHREAD/HK_TYPE_DOMAIN cpumask can be changed at run
time. We need to use RCU to guard access to this cpumask to avoid a
potential UAF problem as the returned cpumask may be freed before it
is being used.

We can replace HK_TYPE_KTHREAD by HK_TYPE_DOMAIN as they are aliases
of each other, but keeping the HK_TYPE_KTHREAD name can highlight the
fact that it is the kthread initiated by ipvs that is being controlled.

Fixes: 03ff73510169 ("cpuset: Update HK_TYPE_DOMAIN cpumask from cpuset")
Signed-off-by: Waiman Long &lt;longman@redhat.com&gt;
Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipvs: fix races around est_mutex and est_cpulist</title>
<updated>2026-05-04T23:52:55+00:00</updated>
<author>
<name>Julian Anastasov</name>
<email>ja@ssi.bg</email>
</author>
<published>2026-04-30T07:44:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2fd109238925d53c44ea409df0558844af7877b8'/>
<id>2fd109238925d53c44ea409df0558844af7877b8</id>
<content type='text'>
Sashiko reports for races and possible crash around
the usage of est_cpulist_valid and sysctl_est_cpulist.
The problem is that we do not lock est_mutex in some
places which can lead to wrong write ordering and
as result problems when calling cpumask_weight()
and cpumask_empty().

Fix them by moving the est_max_threads read/write under
locked est_mutex. Do the same for one ip_vs_est_reload_start()
call to protect the cpumask_empty() usage of sysctl_est_cpulist.

To remove the chance of deadlock while stopping the
estimation kthreads, keep the data structure for kthread 0
even after last estimator is removed and do not hold mutexes
while stopping this task. Now we will use a new flag 'needed'
to know when kthread 0 should run. The kthreads above 0
do not use mutexes, so stop them under est_mutex because
their kthread data still can be destroyed if they do not
serve estimators. Now all kthreads will be started by
the est_reload_work to properly serialize the stop/start
for kthread 0.

Reduce the use of service_mutex in ip_vs_est_calc_phase()
because under est_mutex we can safely walk est_kt_arr to
stop the kthreads above slot 0.

As ip_vs_stop_estimator() for tot_stats should be called
under service_mutex, do it early in the netns exit path
in ip_vs_flush() to avoid locking the mutex again later.
It still should be called in ip_vs_control_net_cleanup_sysctl()
when we are called during netns init error. Use -2 for ktid
as indicator if estimator was already stopped.

Finally, fix use-after-free for kd-&gt;est_row in
ip_vs_est_calc_phase(). est-&gt;ktrow should simply switch to
a delay value while estimator is linked to est_temp_list.

Link: https://sashiko.dev/#/patchset/20260331165015.2777765-1-longman%40redhat.com
Link: https://sashiko.dev/#/patchset/20260420171308.87192-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260422125123.40658-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260424175858.54752-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260425103918.7447-1-ja%40ssi.bg
Fixes: f0be83d54217 ("ipvs: add est_cpulist and est_nice sysctl vars")
Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Sashiko reports for races and possible crash around
the usage of est_cpulist_valid and sysctl_est_cpulist.
The problem is that we do not lock est_mutex in some
places which can lead to wrong write ordering and
as result problems when calling cpumask_weight()
and cpumask_empty().

Fix them by moving the est_max_threads read/write under
locked est_mutex. Do the same for one ip_vs_est_reload_start()
call to protect the cpumask_empty() usage of sysctl_est_cpulist.

To remove the chance of deadlock while stopping the
estimation kthreads, keep the data structure for kthread 0
even after last estimator is removed and do not hold mutexes
while stopping this task. Now we will use a new flag 'needed'
to know when kthread 0 should run. The kthreads above 0
do not use mutexes, so stop them under est_mutex because
their kthread data still can be destroyed if they do not
serve estimators. Now all kthreads will be started by
the est_reload_work to properly serialize the stop/start
for kthread 0.

Reduce the use of service_mutex in ip_vs_est_calc_phase()
because under est_mutex we can safely walk est_kt_arr to
stop the kthreads above slot 0.

As ip_vs_stop_estimator() for tot_stats should be called
under service_mutex, do it early in the netns exit path
in ip_vs_flush() to avoid locking the mutex again later.
It still should be called in ip_vs_control_net_cleanup_sysctl()
when we are called during netns init error. Use -2 for ktid
as indicator if estimator was already stopped.

Finally, fix use-after-free for kd-&gt;est_row in
ip_vs_est_calc_phase(). est-&gt;ktrow should simply switch to
a delay value while estimator is linked to est_temp_list.

Link: https://sashiko.dev/#/patchset/20260331165015.2777765-1-longman%40redhat.com
Link: https://sashiko.dev/#/patchset/20260420171308.87192-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260422125123.40658-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260424175858.54752-1-ja%40ssi.bg
Link: https://sashiko.dev/#/patchset/20260425103918.7447-1-ja%40ssi.bg
Fixes: f0be83d54217 ("ipvs: add est_cpulist and est_nice sysctl vars")
Signed-off-by: Julian Anastasov &lt;ja@ssi.bg&gt;
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'nf-26-05-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf</title>
<updated>2026-05-01T23:45:42+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2026-05-01T23:45:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2ab02ac411a0bbcd2884b30f591f4e4a25c489a4'/>
<id>2ab02ac411a0bbcd2884b30f591f4e4a25c489a4</id>
<content type='text'>
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following batch contains Netfilter fixes for net:

1) Replace skb_try_make_writable() by skb_ensure_writable() in
   nft_fwd_netdev and the flowtable to deal with uncloned packets
   having their network header in paged fragments.

2) Drop packet if output device does not exist and ensure sufficient
   headroom in nft_fwd_netdev before transmitting the skb.

3) Use the existing dup recursion counter in nft_fwd_netdev for the
   neigh_xmit variant, from Weiming Shi.

4) Add .check_hooks interface to x_tables to detach the control plane
   hook check based on the match/target configuration. Then, update
   nft_compat to use .check_hooks from .validate path, this fixes a
   lack of hook validation for several match/targets.

5) Fix incorrect .usersize in xt_CT, from Florian Westphal.

6) Fix a memleak with netdev tables in dormant state,
   from Florian Westphal.

7) Several patches to check if the packet is a fragment, then skip
   layer 4 inspection, for x_tables and nf_tables; as well as common
   nf_socket infrastructure. The xt_hashlimit match drops fragments
   to stay consistent with the existing approach when failing to parse
   the layer 4 protocol header.

8) Ensure sufficient headroom in the flowtable before transmitting
   the skb.

9) Fix the flowtable inline vlan approach for double-tagged vlan:
   Reverse the iteration over .encap[] since it represents the
   encapsulation as seen from the ingress path. Postpone pushing
   layer 2 header so output device is available to calculate needed
   headroom. Finally, add and use nf_flow_vlan_push() to fix it.

10) Fix flowtable inline pppoe with GSO packets. Moreover, use
    FLOW_OFFLOAD_XMIT_DIRECT to fill up destination hardware
    address since neighbour cache does not exist in pppoe.

11) Use skb_pull_rcsum() to decapsulate vlan and pppoe headers, for
    double-tagged vlan in particular this should provide some benefits
    in certain scenarios.

More notes regarding 9-11):

- sashiko is also signalling to use it for IPIP headers, but that needs
  more adjustments such setting skb-&gt;protocol after removing the IPIP
  header, will follow up in a separated patch.
- I plan to submit selftests to cover double-tagged-vlan. As for pppoe,
  it should be possible but that would mandate a few userspace dependencies.
  This has been semi-automatically  tested by me and reporters describing
  broken double-vlan-tagged and pppoe currently in the flowtable.

* tag 'nf-26-05-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: flowtable: use skb_pull_rcsum() to pop vlan/pppoe header
  netfilter: flowtable: fix inline pppoe encapsulation in xmit path
  netfilter: flowtable: fix inline vlan encapsulation in xmit path
  netfilter: flowtable: ensure sufficient headroom in xmit path
  netfilter: xtables: fix L4 header parsing for non-first fragments
  netfilter: nf_tables: skip L4 header parsing for non-first fragments
  netfilter: nf_socket: skip socket lookup for non-first fragments
  netfilter: nf_tables: fix netdev hook allocation memleak with dormant tables
  netfilter: xt_CT: fix usersize for v1 and v2 revision
  netfilter: nft_compat: run xt_check_hooks_{match,target}() from .validate
  netfilter: x_tables: add .check_hooks to matches and targets
  netfilter: nft_fwd_netdev: use recursion counter in neigh egress path
  netfilter: nft_fwd_netdev: add device and headroom validate with neigh forwarding
  netfilter: replace skb_try_make_writable() by skb_ensure_writable()
====================

Link: https://patch.msgid.link/20260501122237.296262-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following batch contains Netfilter fixes for net:

1) Replace skb_try_make_writable() by skb_ensure_writable() in
   nft_fwd_netdev and the flowtable to deal with uncloned packets
   having their network header in paged fragments.

2) Drop packet if output device does not exist and ensure sufficient
   headroom in nft_fwd_netdev before transmitting the skb.

3) Use the existing dup recursion counter in nft_fwd_netdev for the
   neigh_xmit variant, from Weiming Shi.

4) Add .check_hooks interface to x_tables to detach the control plane
   hook check based on the match/target configuration. Then, update
   nft_compat to use .check_hooks from .validate path, this fixes a
   lack of hook validation for several match/targets.

5) Fix incorrect .usersize in xt_CT, from Florian Westphal.

6) Fix a memleak with netdev tables in dormant state,
   from Florian Westphal.

7) Several patches to check if the packet is a fragment, then skip
   layer 4 inspection, for x_tables and nf_tables; as well as common
   nf_socket infrastructure. The xt_hashlimit match drops fragments
   to stay consistent with the existing approach when failing to parse
   the layer 4 protocol header.

8) Ensure sufficient headroom in the flowtable before transmitting
   the skb.

9) Fix the flowtable inline vlan approach for double-tagged vlan:
   Reverse the iteration over .encap[] since it represents the
   encapsulation as seen from the ingress path. Postpone pushing
   layer 2 header so output device is available to calculate needed
   headroom. Finally, add and use nf_flow_vlan_push() to fix it.

10) Fix flowtable inline pppoe with GSO packets. Moreover, use
    FLOW_OFFLOAD_XMIT_DIRECT to fill up destination hardware
    address since neighbour cache does not exist in pppoe.

11) Use skb_pull_rcsum() to decapsulate vlan and pppoe headers, for
    double-tagged vlan in particular this should provide some benefits
    in certain scenarios.

More notes regarding 9-11):

- sashiko is also signalling to use it for IPIP headers, but that needs
  more adjustments such setting skb-&gt;protocol after removing the IPIP
  header, will follow up in a separated patch.
- I plan to submit selftests to cover double-tagged-vlan. As for pppoe,
  it should be possible but that would mandate a few userspace dependencies.
  This has been semi-automatically  tested by me and reporters describing
  broken double-vlan-tagged and pppoe currently in the flowtable.

* tag 'nf-26-05-01' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
  netfilter: flowtable: use skb_pull_rcsum() to pop vlan/pppoe header
  netfilter: flowtable: fix inline pppoe encapsulation in xmit path
  netfilter: flowtable: fix inline vlan encapsulation in xmit path
  netfilter: flowtable: ensure sufficient headroom in xmit path
  netfilter: xtables: fix L4 header parsing for non-first fragments
  netfilter: nf_tables: skip L4 header parsing for non-first fragments
  netfilter: nf_socket: skip socket lookup for non-first fragments
  netfilter: nf_tables: fix netdev hook allocation memleak with dormant tables
  netfilter: xt_CT: fix usersize for v1 and v2 revision
  netfilter: nft_compat: run xt_check_hooks_{match,target}() from .validate
  netfilter: x_tables: add .check_hooks to matches and targets
  netfilter: nft_fwd_netdev: use recursion counter in neigh egress path
  netfilter: nft_fwd_netdev: add device and headroom validate with neigh forwarding
  netfilter: replace skb_try_make_writable() by skb_ensure_writable()
====================

Link: https://patch.msgid.link/20260501122237.296262-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ipv6: Implement limits on extension header parsing</title>
<updated>2026-05-01T00:21:45+00:00</updated>
<author>
<name>Daniel Borkmann</name>
<email>daniel@iogearbox.net</email>
</author>
<published>2026-04-29T15:46:48+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=3744b0964d5267c0b651bcd8f8c25db6bf4ccbac'/>
<id>3744b0964d5267c0b651bcd8f8c25db6bf4ccbac</id>
<content type='text'>
ipv6_{skip_exthdr,find_hdr}() and ip6_{tnl_parse_tlv_enc_lim,
protocol_deliver_rcu}() iterate over IPv6 extension headers until they
find a non-extension-header protocol or run out of packet data. The
loops have no iteration counter, relying solely on the packet length
to bound them. For a crafted packet with 8-byte extension headers
filling a 64KB jumbogram, this means a worst case of up to ~8k
iterations with a skb_header_pointer call each. ipv6_skip_exthdr(),
for example, is used where it parses the inner quoted packet inside
an incoming ICMPv6 error:

  - icmpv6_rcv
    - checksum validation
    - case ICMPV6_DEST_UNREACH
      - icmpv6_notify
        - pskb_may_pull()       &lt;- pull inner IPv6 header
        - ipv6_skip_exthdr()    &lt;- iterates here
        - pskb_may_pull()
        - ipprot-&gt;err_handler() &lt;- sk lookup

The per-iteration cost of ipv6_skip_exthdr itself is generally
light, but skb_header_pointer becomes more costly on reassembled
packets: the first ~1232 bytes of the inner packet are in the skb's
linear area, but the remaining ~63KB are in the frag_list where
skb_copy_bits is needed to read data.

Initially, the idea was to add a configurable limit via a new
sysctl knob with default 8, in line with knobs from commit
47d3d7ac656a ("ipv6: Implement limits on Hop-by-Hop and Destination
options"), but two reasons eventually argued against it:

- It adds to UAPI that needs to be maintained forever, and
  upcoming work is restricting extension header ordering anyway,
  leaving little reason for another sysctl knob
- exthdrs_core.c is always built-in even when CONFIG_IPV6=n,
  where struct net has no .ipv6 member, so the read site would
  need an ifdef'd fallback to a constant anyway

Therefore, just use a constant (IP6_MAX_EXT_HDRS_CNT). All four
extension header walking functions are now bound by this limit.

Note that the check in ip6_protocol_deliver_rcu() happens right
before the goto resubmit, such that we don't have to have a test
for ipv6_ext_hdr() in the fast-path.

There's an ongoing IETF draft-iurman-6man-eh-occurrences to enforce
IPv6 extension headers ordering and occurrence. The latter also
discusses security implications. As per RFC8200 section 4.1, the
occurrence rules for extension headers provide a practical upper
bound which is 8. In order to be conservative, let's define
IP6_MAX_EXT_HDRS_CNT as 12 to leave enough room for quirky setups.
In the unlikely event that this is still not enough, then we might
need to reconsider a sysctl.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Justin Iurman &lt;justin.iurman@gmail.com&gt;
Link: https://patch.msgid.link/20260429154648.809751-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
ipv6_{skip_exthdr,find_hdr}() and ip6_{tnl_parse_tlv_enc_lim,
protocol_deliver_rcu}() iterate over IPv6 extension headers until they
find a non-extension-header protocol or run out of packet data. The
loops have no iteration counter, relying solely on the packet length
to bound them. For a crafted packet with 8-byte extension headers
filling a 64KB jumbogram, this means a worst case of up to ~8k
iterations with a skb_header_pointer call each. ipv6_skip_exthdr(),
for example, is used where it parses the inner quoted packet inside
an incoming ICMPv6 error:

  - icmpv6_rcv
    - checksum validation
    - case ICMPV6_DEST_UNREACH
      - icmpv6_notify
        - pskb_may_pull()       &lt;- pull inner IPv6 header
        - ipv6_skip_exthdr()    &lt;- iterates here
        - pskb_may_pull()
        - ipprot-&gt;err_handler() &lt;- sk lookup

The per-iteration cost of ipv6_skip_exthdr itself is generally
light, but skb_header_pointer becomes more costly on reassembled
packets: the first ~1232 bytes of the inner packet are in the skb's
linear area, but the remaining ~63KB are in the frag_list where
skb_copy_bits is needed to read data.

Initially, the idea was to add a configurable limit via a new
sysctl knob with default 8, in line with knobs from commit
47d3d7ac656a ("ipv6: Implement limits on Hop-by-Hop and Destination
options"), but two reasons eventually argued against it:

- It adds to UAPI that needs to be maintained forever, and
  upcoming work is restricting extension header ordering anyway,
  leaving little reason for another sysctl knob
- exthdrs_core.c is always built-in even when CONFIG_IPV6=n,
  where struct net has no .ipv6 member, so the read site would
  need an ifdef'd fallback to a constant anyway

Therefore, just use a constant (IP6_MAX_EXT_HDRS_CNT). All four
extension header walking functions are now bound by this limit.

Note that the check in ip6_protocol_deliver_rcu() happens right
before the goto resubmit, such that we don't have to have a test
for ipv6_ext_hdr() in the fast-path.

There's an ongoing IETF draft-iurman-6man-eh-occurrences to enforce
IPv6 extension headers ordering and occurrence. The latter also
discusses security implications. As per RFC8200 section 4.1, the
occurrence rules for extension headers provide a practical upper
bound which is 8. In order to be conservative, let's define
IP6_MAX_EXT_HDRS_CNT as 12 to leave enough room for quirky setups.
In the unlikely event that this is still not enough, then we might
need to reconsider a sysctl.

Signed-off-by: Daniel Borkmann &lt;daniel@iogearbox.net&gt;
Reviewed-by: Ido Schimmel &lt;idosch@nvidia.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Justin Iurman &lt;justin.iurman@gmail.com&gt;
Link: https://patch.msgid.link/20260429154648.809751-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>netfilter: flowtable: fix inline pppoe encapsulation in xmit path</title>
<updated>2026-04-30T23:24:01+00:00</updated>
<author>
<name>Pablo Neira Ayuso</name>
<email>pablo@netfilter.org</email>
</author>
<published>2026-04-30T14:49:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=69c54f80f4a7072b51b5b5939185ca5e572be982'/>
<id>69c54f80f4a7072b51b5b5939185ca5e572be982</id>
<content type='text'>
Address two issues in the inline pppoe encapsulation:

- Add needs_gso_segment flag to segment PPPoE packets in software
  given that there is no GSO support for this.

- Use FLOW_OFFLOAD_XMIT_DIRECT since neighbour cache is not available
  in point-to-point device, use the hardware address that is obtained
  via flowtable path discovery (ie. fill_forward_path).

Fixes: 18d27bed0880 ("netfilter: flowtable: inline pppoe encapsulation in xmit path")
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Address two issues in the inline pppoe encapsulation:

- Add needs_gso_segment flag to segment PPPoE packets in software
  given that there is no GSO support for this.

- Use FLOW_OFFLOAD_XMIT_DIRECT since neighbour cache is not available
  in point-to-point device, use the hardware address that is obtained
  via flowtable path discovery (ie. fill_forward_path).

Fixes: 18d27bed0880 ("netfilter: flowtable: inline pppoe encapsulation in xmit path")
Signed-off-by: Pablo Neira Ayuso &lt;pablo@netfilter.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>bonding: 3ad: implement proper RCU rules for port-&gt;aggregator</title>
<updated>2026-04-30T01:32:02+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2026-04-28T12:32:07+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=c4f050ce06c56cfb5993268af4a5cb66ed1cd04e'/>
<id>c4f050ce06c56cfb5993268af4a5cb66ed1cd04e</id>
<content type='text'>
syzbot found a data-race in bond_3ad_get_active_agg_info /
bond_3ad_state_machine_handler [1] which hints at lack of proper
RCU implementation.

Add __rcu qualifier to port-&gt;aggregator, and add proper RCU API.

[1]

BUG: KCSAN: data-race in bond_3ad_get_active_agg_info / bond_3ad_state_machine_handler

write to 0xffff88813cf5c4b0 of 8 bytes by task 36 on cpu 0:
  ad_port_selection_logic drivers/net/bonding/bond_3ad.c:1659 [inline]
  bond_3ad_state_machine_handler+0x9d5/0x2d60 drivers/net/bonding/bond_3ad.c:2569
  process_one_work kernel/workqueue.c:3302 [inline]
  process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3385
  worker_thread+0x58a/0x780 kernel/workqueue.c:3466
  kthread+0x22a/0x280 kernel/kthread.c:436
  ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88813cf5c4b0 of 8 bytes by task 22063 on cpu 1:
  __bond_3ad_get_active_agg_info drivers/net/bonding/bond_3ad.c:2858 [inline]
  bond_3ad_get_active_agg_info+0x8c/0x230 drivers/net/bonding/bond_3ad.c:2881
  bond_fill_info+0xe0f/0x10f0 drivers/net/bonding/bond_netlink.c:853
  rtnl_link_info_fill net/core/rtnetlink.c:906 [inline]
  rtnl_link_fill+0x1d7/0x4e0 net/core/rtnetlink.c:927
  rtnl_fill_ifinfo+0xf8e/0x1380 net/core/rtnetlink.c:2168
  rtmsg_ifinfo_build_skb+0x11c/0x1b0 net/core/rtnetlink.c:4453
  rtmsg_ifinfo_event net/core/rtnetlink.c:4486 [inline]
  rtmsg_ifinfo+0x6d/0x110 net/core/rtnetlink.c:4495
  __dev_notify_flags+0x76/0x390 net/core/dev.c:9790
  netif_change_flags+0xac/0xd0 net/core/dev.c:9823
  do_setlink+0x905/0x2950 net/core/rtnetlink.c:3180
  rtnl_group_changelink net/core/rtnetlink.c:3813 [inline]
  __rtnl_newlink net/core/rtnetlink.c:3981 [inline]
  rtnl_newlink+0xf55/0x1400 net/core/rtnetlink.c:4109
  rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6995
  netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550
  rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7022
  netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
  netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1344
  netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894
  sock_sendmsg_nosec net/socket.c:787 [inline]
  __sock_sendmsg net/socket.c:802 [inline]
  ____sys_sendmsg+0x563/0x5b0 net/socket.c:2698
  ___sys_sendmsg+0x195/0x1e0 net/socket.c:2752
  __sys_sendmsg net/socket.c:2784 [inline]
  __do_sys_sendmsg net/socket.c:2789 [inline]
  __se_sys_sendmsg net/socket.c:2787 [inline]
  __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2787
  x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -&gt; 0xffff88813cf5c400

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22063 Comm: syz.0.31122 Tainted: G        W           syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026

Fixes: 47e91f56008b ("bonding: use RCU protection for 3ad xmit path")
Reported-by: syzbot+9bb2ff2a4ab9e17307e1@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69f0a82f.050a0220.3aadc4.0000.GAE@google.com/
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Jay Vosburgh &lt;jv@jvosburgh.net&gt;
Cc: Andrew Lunn &lt;andrew+netdev@lunn.ch&gt;
Link: https://patch.msgid.link/20260428123207.3809211-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot found a data-race in bond_3ad_get_active_agg_info /
bond_3ad_state_machine_handler [1] which hints at lack of proper
RCU implementation.

Add __rcu qualifier to port-&gt;aggregator, and add proper RCU API.

[1]

BUG: KCSAN: data-race in bond_3ad_get_active_agg_info / bond_3ad_state_machine_handler

write to 0xffff88813cf5c4b0 of 8 bytes by task 36 on cpu 0:
  ad_port_selection_logic drivers/net/bonding/bond_3ad.c:1659 [inline]
  bond_3ad_state_machine_handler+0x9d5/0x2d60 drivers/net/bonding/bond_3ad.c:2569
  process_one_work kernel/workqueue.c:3302 [inline]
  process_scheduled_works+0x4f0/0x9c0 kernel/workqueue.c:3385
  worker_thread+0x58a/0x780 kernel/workqueue.c:3466
  kthread+0x22a/0x280 kernel/kthread.c:436
  ret_from_fork+0x146/0x330 arch/x86/kernel/process.c:158
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

read to 0xffff88813cf5c4b0 of 8 bytes by task 22063 on cpu 1:
  __bond_3ad_get_active_agg_info drivers/net/bonding/bond_3ad.c:2858 [inline]
  bond_3ad_get_active_agg_info+0x8c/0x230 drivers/net/bonding/bond_3ad.c:2881
  bond_fill_info+0xe0f/0x10f0 drivers/net/bonding/bond_netlink.c:853
  rtnl_link_info_fill net/core/rtnetlink.c:906 [inline]
  rtnl_link_fill+0x1d7/0x4e0 net/core/rtnetlink.c:927
  rtnl_fill_ifinfo+0xf8e/0x1380 net/core/rtnetlink.c:2168
  rtmsg_ifinfo_build_skb+0x11c/0x1b0 net/core/rtnetlink.c:4453
  rtmsg_ifinfo_event net/core/rtnetlink.c:4486 [inline]
  rtmsg_ifinfo+0x6d/0x110 net/core/rtnetlink.c:4495
  __dev_notify_flags+0x76/0x390 net/core/dev.c:9790
  netif_change_flags+0xac/0xd0 net/core/dev.c:9823
  do_setlink+0x905/0x2950 net/core/rtnetlink.c:3180
  rtnl_group_changelink net/core/rtnetlink.c:3813 [inline]
  __rtnl_newlink net/core/rtnetlink.c:3981 [inline]
  rtnl_newlink+0xf55/0x1400 net/core/rtnetlink.c:4109
  rtnetlink_rcv_msg+0x64b/0x720 net/core/rtnetlink.c:6995
  netlink_rcv_skb+0x123/0x220 net/netlink/af_netlink.c:2550
  rtnetlink_rcv+0x1c/0x30 net/core/rtnetlink.c:7022
  netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
  netlink_unicast+0x5a8/0x680 net/netlink/af_netlink.c:1344
  netlink_sendmsg+0x5c8/0x6f0 net/netlink/af_netlink.c:1894
  sock_sendmsg_nosec net/socket.c:787 [inline]
  __sock_sendmsg net/socket.c:802 [inline]
  ____sys_sendmsg+0x563/0x5b0 net/socket.c:2698
  ___sys_sendmsg+0x195/0x1e0 net/socket.c:2752
  __sys_sendmsg net/socket.c:2784 [inline]
  __do_sys_sendmsg net/socket.c:2789 [inline]
  __se_sys_sendmsg net/socket.c:2787 [inline]
  __x64_sys_sendmsg+0xd4/0x160 net/socket.c:2787
  x64_sys_call+0x194c/0x3020 arch/x86/include/generated/asm/syscalls_64.h:47
  do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
  do_syscall_64+0x12c/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

value changed: 0x0000000000000000 -&gt; 0xffff88813cf5c400

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 UID: 0 PID: 22063 Comm: syz.0.31122 Tainted: G        W           syzkaller #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026

Fixes: 47e91f56008b ("bonding: use RCU protection for 3ad xmit path")
Reported-by: syzbot+9bb2ff2a4ab9e17307e1@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/69f0a82f.050a0220.3aadc4.0000.GAE@google.com/
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Jay Vosburgh &lt;jv@jvosburgh.net&gt;
Cc: Andrew Lunn &lt;andrew+netdev@lunn.ch&gt;
Link: https://patch.msgid.link/20260428123207.3809211-1-edumazet@google.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
