<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/core, branch v6.3</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>xdp: rss hash types representation</title>
<updated>2023-04-13T18:15:10+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2023-04-12T19:48:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0cd917a4a8ace70ff9082d797c899f6bf10de910'/>
<id>0cd917a4a8ace70ff9082d797c899f6bf10de910</id>
<content type='text'>
The RSS hash type specifies what portion of packet data NIC hardware used
when calculating RSS hash value. The RSS types are focused on Internet
traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash
value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4
primarily TCP vs UDP, but some hardware supports SCTP.

Hardware RSS types are differently encoded for each hardware NIC. Most
hardware represent RSS hash type as a number. Determining L3 vs L4 often
requires a mapping table as there often isn't a pattern or sorting
according to ISO layer.

The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that
contains both BITs for the L3/L4 types, and combinations to be used by
drivers for their mapping tables. The enum xdp_rss_type_bits get exposed
to BPF via BTF, and it is up to the BPF-programmer to match using these
defines.

This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding
a pointer value argument for provide the RSS hash type.
Change signature for all xmo_rx_hash calls in drivers to make it compile.

The RSS type implementations for each driver comes as separate patches.

Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The RSS hash type specifies what portion of packet data NIC hardware used
when calculating RSS hash value. The RSS types are focused on Internet
traffic protocols at OSI layers L3 and L4. L2 (e.g. ARP) often get hash
value zero and no RSS type. For L3 focused on IPv4 vs. IPv6, and L4
primarily TCP vs UDP, but some hardware supports SCTP.

Hardware RSS types are differently encoded for each hardware NIC. Most
hardware represent RSS hash type as a number. Determining L3 vs L4 often
requires a mapping table as there often isn't a pattern or sorting
according to ISO layer.

The patch introduce a XDP RSS hash type (enum xdp_rss_hash_type) that
contains both BITs for the L3/L4 types, and combinations to be used by
drivers for their mapping tables. The enum xdp_rss_type_bits get exposed
to BPF via BTF, and it is up to the BPF-programmer to match using these
defines.

This proposal change the kfunc API bpf_xdp_metadata_rx_hash() adding
a pointer value argument for provide the RSS hash type.
Change signature for all xmo_rx_hash calls in drivers to make it compile.

The RSS type implementations for each driver comes as separate patches.

Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Link: https://lore.kernel.org/r/168132892042.340624.582563003880565460.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>skbuff: Fix a race between coalescing and releasing SKBs</title>
<updated>2023-04-13T17:08:42+00:00</updated>
<author>
<name>Liang Chen</name>
<email>liangchen.linux@gmail.com</email>
</author>
<published>2023-04-13T09:03:53+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0646dc31ca886693274df5749cd0c8c1eaaeb5ca'/>
<id>0646dc31ca886693274df5749cd0c8c1eaaeb5ca</id>
<content type='text'>
Commit 1effe8ca4e34 ("skbuff: fix coalescing for page_pool fragment
recycling") allowed coalescing to proceed with non page pool page and page
pool page when @from is cloned, i.e.

to-&gt;pp_recycle    --&gt; false
from-&gt;pp_recycle  --&gt; true
skb_cloned(from)  --&gt; true

However, it actually requires skb_cloned(@from) to hold true until
coalescing finishes in this situation. If the other cloned SKB is
released while the merging is in process, from_shinfo-&gt;nr_frags will be
set to 0 toward the end of the function, causing the increment of frag
page _refcount to be unexpectedly skipped resulting in inconsistent
reference counts. Later when SKB(@to) is released, it frees the page
directly even though the page pool page is still in use, leading to
use-after-free or double-free errors. So it should be prohibited.

The double-free error message below prompted us to investigate:
BUG: Bad page state in process swapper/1  pfn:0e0d1
page:00000000c6548b28 refcount:-1 mapcount:0 mapping:0000000000000000
index:0x2 pfn:0xe0d1
flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000000 0000000000000000 ffffffff00000101 0000000000000000
raw: 0000000000000002 0000000000000000 ffffffffffffffff 0000000000000000
page dumped because: nonzero _refcount

CPU: 1 PID: 0 Comm: swapper/1 Tainted: G            E      6.2.0+
Call Trace:
 &lt;IRQ&gt;
dump_stack_lvl+0x32/0x50
bad_page+0x69/0xf0
free_pcp_prepare+0x260/0x2f0
free_unref_page+0x20/0x1c0
skb_release_data+0x10b/0x1a0
napi_consume_skb+0x56/0x150
net_rx_action+0xf0/0x350
? __napi_schedule+0x79/0x90
__do_softirq+0xc8/0x2b1
__irq_exit_rcu+0xb9/0xf0
common_interrupt+0x82/0xa0
&lt;/IRQ&gt;
&lt;TASK&gt;
asm_common_interrupt+0x22/0x40
RIP: 0010:default_idle+0xb/0x20

Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool")
Signed-off-by: Liang Chen &lt;liangchen.linux@gmail.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20230413090353.14448-1-liangchen.linux@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 1effe8ca4e34 ("skbuff: fix coalescing for page_pool fragment
recycling") allowed coalescing to proceed with non page pool page and page
pool page when @from is cloned, i.e.

to-&gt;pp_recycle    --&gt; false
from-&gt;pp_recycle  --&gt; true
skb_cloned(from)  --&gt; true

However, it actually requires skb_cloned(@from) to hold true until
coalescing finishes in this situation. If the other cloned SKB is
released while the merging is in process, from_shinfo-&gt;nr_frags will be
set to 0 toward the end of the function, causing the increment of frag
page _refcount to be unexpectedly skipped resulting in inconsistent
reference counts. Later when SKB(@to) is released, it frees the page
directly even though the page pool page is still in use, leading to
use-after-free or double-free errors. So it should be prohibited.

The double-free error message below prompted us to investigate:
BUG: Bad page state in process swapper/1  pfn:0e0d1
page:00000000c6548b28 refcount:-1 mapcount:0 mapping:0000000000000000
index:0x2 pfn:0xe0d1
flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000000 0000000000000000 ffffffff00000101 0000000000000000
raw: 0000000000000002 0000000000000000 ffffffffffffffff 0000000000000000
page dumped because: nonzero _refcount

CPU: 1 PID: 0 Comm: swapper/1 Tainted: G            E      6.2.0+
Call Trace:
 &lt;IRQ&gt;
dump_stack_lvl+0x32/0x50
bad_page+0x69/0xf0
free_pcp_prepare+0x260/0x2f0
free_unref_page+0x20/0x1c0
skb_release_data+0x10b/0x1a0
napi_consume_skb+0x56/0x150
net_rx_action+0xf0/0x350
? __napi_schedule+0x79/0x90
__do_softirq+0xc8/0x2b1
__irq_exit_rcu+0xb9/0xf0
common_interrupt+0x82/0xa0
&lt;/IRQ&gt;
&lt;TASK&gt;
asm_common_interrupt+0x22/0x40
RIP: 0010:default_idle+0xb/0x20

Fixes: 53e0961da1c7 ("page_pool: add frag page recycling support in page pool")
Signed-off-by: Liang Chen &lt;liangchen.linux@gmail.com&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Link: https://lore.kernel.org/r/20230413090353.14448-1-liangchen.linux@gmail.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>rtnetlink: Restore RTM_NEW/DELLINK notification behavior</title>
<updated>2023-04-13T03:47:58+00:00</updated>
<author>
<name>Martin Willi</name>
<email>martin@strongswan.org</email>
</author>
<published>2023-04-11T07:43:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=59d3efd27c11c59b32291e5ebc307bed2edb65ee'/>
<id>59d3efd27c11c59b32291e5ebc307bed2edb65ee</id>
<content type='text'>
The commits referenced below allows userspace to use the NLM_F_ECHO flag
for RTM_NEW/DELLINK operations to receive unicast notifications for the
affected link. Prior to these changes, applications may have relied on
multicast notifications to learn the same information without specifying
the NLM_F_ECHO flag.

For such applications, the mentioned commits changed the behavior for
requests not using NLM_F_ECHO. Multicast notifications are still received,
but now use the portid of the requester and the sequence number of the
request instead of zero values used previously. For the application, this
message may be unexpected and likely handled as a response to the
NLM_F_ACKed request, especially if it uses the same socket to handle
requests and notifications.

To fix existing applications relying on the old notification behavior,
set the portid and sequence number in the notification only if the
request included the NLM_F_ECHO flag. This restores the old behavior
for applications not using it, but allows unicasted notifications for
others.

Fixes: f3a63cce1b4f ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link")
Fixes: d88e136cab37 ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create")
Signed-off-by: Martin Willi &lt;martin@strongswan.org&gt;
Acked-by: Guillaume Nault &lt;gnault@redhat.com&gt;
Acked-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Link: https://lore.kernel.org/r/20230411074319.24133-1-martin@strongswan.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The commits referenced below allows userspace to use the NLM_F_ECHO flag
for RTM_NEW/DELLINK operations to receive unicast notifications for the
affected link. Prior to these changes, applications may have relied on
multicast notifications to learn the same information without specifying
the NLM_F_ECHO flag.

For such applications, the mentioned commits changed the behavior for
requests not using NLM_F_ECHO. Multicast notifications are still received,
but now use the portid of the requester and the sequence number of the
request instead of zero values used previously. For the application, this
message may be unexpected and likely handled as a response to the
NLM_F_ACKed request, especially if it uses the same socket to handle
requests and notifications.

To fix existing applications relying on the old notification behavior,
set the portid and sequence number in the notification only if the
request included the NLM_F_ECHO flag. This restores the old behavior
for applications not using it, but allows unicasted notifications for
others.

Fixes: f3a63cce1b4f ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link")
Fixes: d88e136cab37 ("rtnetlink: Honour NLM_F_ECHO flag in rtnl_newlink_create")
Signed-off-by: Martin Willi &lt;martin@strongswan.org&gt;
Acked-by: Guillaume Nault &lt;gnault@redhat.com&gt;
Acked-by: Hangbin Liu &lt;liuhangbin@gmail.com&gt;
Link: https://lore.kernel.org/r/20230411074319.24133-1-martin@strongswan.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: openvswitch: fix race on port output</title>
<updated>2023-04-08T02:42:53+00:00</updated>
<author>
<name>Felix Huettner</name>
<email>felix.huettner@mail.schwarz</email>
</author>
<published>2023-04-05T07:53:41+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=066b86787fa3d97b7aefb5ac0a99a22dad2d15f8'/>
<id>066b86787fa3d97b7aefb5ac0a99a22dad2d15f8</id>
<content type='text'>
assume the following setup on a single machine:
1. An openvswitch instance with one bridge and default flows
2. two network namespaces "server" and "client"
3. two ovs interfaces "server" and "client" on the bridge
4. for each ovs interface a veth pair with a matching name and 32 rx and
   tx queues
5. move the ends of the veth pairs to the respective network namespaces
6. assign ip addresses to each of the veth ends in the namespaces (needs
   to be the same subnet)
7. start some http server on the server network namespace
8. test if a client in the client namespace can reach the http server

when following the actions below the host has a chance of getting a cpu
stuck in a infinite loop:
1. send a large amount of parallel requests to the http server (around
   3000 curls should work)
2. in parallel delete the network namespace (do not delete interfaces or
   stop the server, just kill the namespace)

there is a low chance that this will cause the below kernel cpu stuck
message. If this does not happen just retry.
Below there is also the output of bpftrace for the functions mentioned
in the output.

The series of events happening here is:
1. the network namespace is deleted calling
   `unregister_netdevice_many_notify` somewhere in the process
2. this sets first `NETREG_UNREGISTERING` on both ends of the veth and
   then runs `synchronize_net`
3. it then calls `call_netdevice_notifiers` with `NETDEV_UNREGISTER`
4. this is then handled by `dp_device_event` which calls
   `ovs_netdev_detach_dev` (if a vport is found, which is the case for
   the veth interface attached to ovs)
5. this removes the rx_handlers of the device but does not prevent
   packages to be sent to the device
6. `dp_device_event` then queues the vport deletion to work in
   background as a ovs_lock is needed that we do not hold in the
   unregistration path
7. `unregister_netdevice_many_notify` continues to call
   `netdev_unregister_kobject` which sets `real_num_tx_queues` to 0
8. port deletion continues (but details are not relevant for this issue)
9. at some future point the background task deletes the vport

If after 7. but before 9. a packet is send to the ovs vport (which is
not deleted at this point in time) which forwards it to the
`dev_queue_xmit` flow even though the device is unregistering.
In `skb_tx_hash` (which is called in the `dev_queue_xmit`) path there is
a while loop (if the packet has a rx_queue recorded) that is infinite if
`dev-&gt;real_num_tx_queues` is zero.

To prevent this from happening we update `do_output` to handle devices
without carrier the same as if the device is not found (which would
be the code path after 9. is done).

Additionally we now produce a warning in `skb_tx_hash` if we will hit
the infinite loop.

bpftrace (first word is function name):

__dev_queue_xmit server: real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 2, reg_state: 1
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 6, reg_state: 2
ovs_netdev_detach_dev server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, reg_state: 2
netdev_rx_handler_unregister server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
netdev_rx_handler_unregister ret server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 27, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 22, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 18, reg_state: 2
netdev_unregister_kobject: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
ovs_vport_send server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
__dev_queue_xmit server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
broken device server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024
ovs_dp_detach_port server: real_num_tx_queues: 0 cpu 9, pid: 9124, tid: 9124, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 33604, tid: 33604

stuck message:

watchdog: BUG: soft lockup - CPU#5 stuck for 26s! [curl:1929279]
Modules linked in: veth pktgen bridge stp llc ip_set_hash_net nft_counter xt_set nft_compat nf_tables ip_set_hash_ip ip_set nfnetlink_cttimeout nfnetlink openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 tls binfmt_misc nls_iso8859_1 input_leds joydev serio_raw dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua sch_fq_codel drm efi_pstore virtio_rng ip_tables x_tables autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel virtio_net ahci net_failover crypto_simd cryptd psmouse libahci virtio_blk failover
CPU: 5 PID: 1929279 Comm: curl Not tainted 5.15.0-67-generic #74-Ubuntu
Hardware name: OpenStack Foundation OpenStack Nova, BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:netdev_pick_tx+0xf1/0x320
Code: 00 00 8d 48 ff 0f b7 c1 66 39 ca 0f 86 e9 01 00 00 45 0f b7 ff 41 39 c7 0f 87 5b 01 00 00 44 29 f8 41 39 c7 0f 87 4f 01 00 00 &lt;eb&gt; f2 0f 1f 44 00 00 49 8b 94 24 28 04 00 00 48 85 d2 0f 84 53 01
RSP: 0018:ffffb78b40298820 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff9c8773adc2e0 RCX: 000000000000083f
RDX: 0000000000000000 RSI: ffff9c8773adc2e0 RDI: ffff9c870a25e000
RBP: ffffb78b40298858 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff9c870a25e000
R13: ffff9c870a25e000 R14: ffff9c87fe043480 R15: 0000000000000000
FS:  00007f7b80008f00(0000) GS:ffff9c8e5f740000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b80f6a0b0 CR3: 0000000329d66000 CR4: 0000000000350ee0
Call Trace:
 &lt;IRQ&gt;
 netdev_core_pick_tx+0xa4/0xb0
 __dev_queue_xmit+0xf8/0x510
 ? __bpf_prog_exit+0x1e/0x30
 dev_queue_xmit+0x10/0x20
 ovs_vport_send+0xad/0x170 [openvswitch]
 do_output+0x59/0x180 [openvswitch]
 do_execute_actions+0xa80/0xaa0 [openvswitch]
 ? kfree+0x1/0x250
 ? kfree+0x1/0x250
 ? kprobe_perf_func+0x4f/0x2b0
 ? flow_lookup.constprop.0+0x5c/0x110 [openvswitch]
 ovs_execute_actions+0x4c/0x120 [openvswitch]
 ovs_dp_process_packet+0xa1/0x200 [openvswitch]
 ? ovs_ct_update_key.isra.0+0xa8/0x120 [openvswitch]
 ? ovs_ct_fill_key+0x1d/0x30 [openvswitch]
 ? ovs_flow_key_extract+0x2db/0x350 [openvswitch]
 ovs_vport_receive+0x77/0xd0 [openvswitch]
 ? __htab_map_lookup_elem+0x4e/0x60
 ? bpf_prog_680e8aff8547aec1_kfree+0x3b/0x714
 ? trace_call_bpf+0xc8/0x150
 ? kfree+0x1/0x250
 ? kfree+0x1/0x250
 ? kprobe_perf_func+0x4f/0x2b0
 ? kprobe_perf_func+0x4f/0x2b0
 ? __mod_memcg_lruvec_state+0x63/0xe0
 netdev_port_receive+0xc4/0x180 [openvswitch]
 ? netdev_port_receive+0x180/0x180 [openvswitch]
 netdev_frame_hook+0x1f/0x40 [openvswitch]
 __netif_receive_skb_core.constprop.0+0x23d/0xf00
 __netif_receive_skb_one_core+0x3f/0xa0
 __netif_receive_skb+0x15/0x60
 process_backlog+0x9e/0x170
 __napi_poll+0x33/0x180
 net_rx_action+0x126/0x280
 ? ttwu_do_activate+0x72/0xf0
 __do_softirq+0xd9/0x2e7
 ? rcu_report_exp_cpu_mult+0x1b0/0x1b0
 do_softirq+0x7d/0xb0
 &lt;/IRQ&gt;
 &lt;TASK&gt;
 __local_bh_enable_ip+0x54/0x60
 ip_finish_output2+0x191/0x460
 __ip_finish_output+0xb7/0x180
 ip_finish_output+0x2e/0xc0
 ip_output+0x78/0x100
 ? __ip_finish_output+0x180/0x180
 ip_local_out+0x5e/0x70
 __ip_queue_xmit+0x184/0x440
 ? tcp_syn_options+0x1f9/0x300
 ip_queue_xmit+0x15/0x20
 __tcp_transmit_skb+0x910/0x9c0
 ? __mod_memcg_state+0x44/0xa0
 tcp_connect+0x437/0x4e0
 ? ktime_get_with_offset+0x60/0xf0
 tcp_v4_connect+0x436/0x530
 __inet_stream_connect+0xd4/0x3a0
 ? kprobe_perf_func+0x4f/0x2b0
 ? aa_sk_perm+0x43/0x1c0
 inet_stream_connect+0x3b/0x60
 __sys_connect_file+0x63/0x70
 __sys_connect+0xa6/0xd0
 ? setfl+0x108/0x170
 ? do_fcntl+0xe8/0x5a0
 __x64_sys_connect+0x18/0x20
 do_syscall_64+0x5c/0xc0
 ? __x64_sys_fcntl+0xa9/0xd0
 ? exit_to_user_mode_prepare+0x37/0xb0
 ? syscall_exit_to_user_mode+0x27/0x50
 ? do_syscall_64+0x69/0xc0
 ? __sys_setsockopt+0xea/0x1e0
 ? exit_to_user_mode_prepare+0x37/0xb0
 ? syscall_exit_to_user_mode+0x27/0x50
 ? __x64_sys_setsockopt+0x1f/0x30
 ? do_syscall_64+0x69/0xc0
 ? irqentry_exit+0x1d/0x30
 ? exc_page_fault+0x89/0x170
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7b8101c6a7
Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89
RSP: 002b:00007ffffd6b2198 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b8101c6a7
RDX: 0000000000000010 RSI: 00007ffffd6b2360 RDI: 0000000000000005
RBP: 0000561f1370d560 R08: 00002795ad21d1ac R09: 0030312e302e302e
R10: 00007ffffd73f080 R11: 0000000000000246 R12: 0000561f1370c410
R13: 0000000000000000 R14: 0000000000000005 R15: 0000000000000000
 &lt;/TASK&gt;

Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action")
Co-developed-by: Luca Czesla &lt;luca.czesla@mail.schwarz&gt;
Signed-off-by: Luca Czesla &lt;luca.czesla@mail.schwarz&gt;
Signed-off-by: Felix Huettner &lt;felix.huettner@mail.schwarz&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Link: https://lore.kernel.org/r/ZC0pBXBAgh7c76CA@kernel-bug-kernel-bug
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
assume the following setup on a single machine:
1. An openvswitch instance with one bridge and default flows
2. two network namespaces "server" and "client"
3. two ovs interfaces "server" and "client" on the bridge
4. for each ovs interface a veth pair with a matching name and 32 rx and
   tx queues
5. move the ends of the veth pairs to the respective network namespaces
6. assign ip addresses to each of the veth ends in the namespaces (needs
   to be the same subnet)
7. start some http server on the server network namespace
8. test if a client in the client namespace can reach the http server

when following the actions below the host has a chance of getting a cpu
stuck in a infinite loop:
1. send a large amount of parallel requests to the http server (around
   3000 curls should work)
2. in parallel delete the network namespace (do not delete interfaces or
   stop the server, just kill the namespace)

there is a low chance that this will cause the below kernel cpu stuck
message. If this does not happen just retry.
Below there is also the output of bpftrace for the functions mentioned
in the output.

The series of events happening here is:
1. the network namespace is deleted calling
   `unregister_netdevice_many_notify` somewhere in the process
2. this sets first `NETREG_UNREGISTERING` on both ends of the veth and
   then runs `synchronize_net`
3. it then calls `call_netdevice_notifiers` with `NETDEV_UNREGISTER`
4. this is then handled by `dp_device_event` which calls
   `ovs_netdev_detach_dev` (if a vport is found, which is the case for
   the veth interface attached to ovs)
5. this removes the rx_handlers of the device but does not prevent
   packages to be sent to the device
6. `dp_device_event` then queues the vport deletion to work in
   background as a ovs_lock is needed that we do not hold in the
   unregistration path
7. `unregister_netdevice_many_notify` continues to call
   `netdev_unregister_kobject` which sets `real_num_tx_queues` to 0
8. port deletion continues (but details are not relevant for this issue)
9. at some future point the background task deletes the vport

If after 7. but before 9. a packet is send to the ovs vport (which is
not deleted at this point in time) which forwards it to the
`dev_queue_xmit` flow even though the device is unregistering.
In `skb_tx_hash` (which is called in the `dev_queue_xmit`) path there is
a while loop (if the packet has a rx_queue recorded) that is infinite if
`dev-&gt;real_num_tx_queues` is zero.

To prevent this from happening we update `do_output` to handle devices
without carrier the same as if the device is not found (which would
be the code path after 9. is done).

Additionally we now produce a warning in `skb_tx_hash` if we will hit
the infinite loop.

bpftrace (first word is function name):

__dev_queue_xmit server: real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 1, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 1
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 2, reg_state: 1
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 6, reg_state: 2
ovs_netdev_detach_dev server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, reg_state: 2
netdev_rx_handler_unregister server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
netdev_rx_handler_unregister ret server: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 27, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 22, reg_state: 2
dp_device_event server: real_num_tx_queues: 1 cpu 9, pid: 21024, tid: 21024, event 18, reg_state: 2
netdev_unregister_kobject: real_num_tx_queues: 1, cpu: 9, pid: 21024, tid: 21024
synchronize_rcu_expedited: cpu 9, pid: 21024, tid: 21024
ovs_vport_send server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
__dev_queue_xmit server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
netdev_core_pick_tx server: addr: 0xffff9f0a46d4a000 real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024, skb_addr: 0xffff9edb6f207000, reg_state: 2
broken device server: real_num_tx_queues: 0, cpu: 2, pid: 28024, tid: 28024
ovs_dp_detach_port server: real_num_tx_queues: 0 cpu 9, pid: 9124, tid: 9124, reg_state: 2
synchronize_rcu_expedited: cpu 9, pid: 33604, tid: 33604

stuck message:

watchdog: BUG: soft lockup - CPU#5 stuck for 26s! [curl:1929279]
Modules linked in: veth pktgen bridge stp llc ip_set_hash_net nft_counter xt_set nft_compat nf_tables ip_set_hash_ip ip_set nfnetlink_cttimeout nfnetlink openvswitch nsh nf_conncount nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 tls binfmt_misc nls_iso8859_1 input_leds joydev serio_raw dm_multipath scsi_dh_rdac scsi_dh_emc scsi_dh_alua sch_fq_codel drm efi_pstore virtio_rng ip_tables x_tables autofs4 btrfs blake2b_generic zstd_compress raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c raid1 raid0 multipath linear hid_generic usbhid hid crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel virtio_net ahci net_failover crypto_simd cryptd psmouse libahci virtio_blk failover
CPU: 5 PID: 1929279 Comm: curl Not tainted 5.15.0-67-generic #74-Ubuntu
Hardware name: OpenStack Foundation OpenStack Nova, BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:netdev_pick_tx+0xf1/0x320
Code: 00 00 8d 48 ff 0f b7 c1 66 39 ca 0f 86 e9 01 00 00 45 0f b7 ff 41 39 c7 0f 87 5b 01 00 00 44 29 f8 41 39 c7 0f 87 4f 01 00 00 &lt;eb&gt; f2 0f 1f 44 00 00 49 8b 94 24 28 04 00 00 48 85 d2 0f 84 53 01
RSP: 0018:ffffb78b40298820 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff9c8773adc2e0 RCX: 000000000000083f
RDX: 0000000000000000 RSI: ffff9c8773adc2e0 RDI: ffff9c870a25e000
RBP: ffffb78b40298858 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff9c870a25e000
R13: ffff9c870a25e000 R14: ffff9c87fe043480 R15: 0000000000000000
FS:  00007f7b80008f00(0000) GS:ffff9c8e5f740000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7b80f6a0b0 CR3: 0000000329d66000 CR4: 0000000000350ee0
Call Trace:
 &lt;IRQ&gt;
 netdev_core_pick_tx+0xa4/0xb0
 __dev_queue_xmit+0xf8/0x510
 ? __bpf_prog_exit+0x1e/0x30
 dev_queue_xmit+0x10/0x20
 ovs_vport_send+0xad/0x170 [openvswitch]
 do_output+0x59/0x180 [openvswitch]
 do_execute_actions+0xa80/0xaa0 [openvswitch]
 ? kfree+0x1/0x250
 ? kfree+0x1/0x250
 ? kprobe_perf_func+0x4f/0x2b0
 ? flow_lookup.constprop.0+0x5c/0x110 [openvswitch]
 ovs_execute_actions+0x4c/0x120 [openvswitch]
 ovs_dp_process_packet+0xa1/0x200 [openvswitch]
 ? ovs_ct_update_key.isra.0+0xa8/0x120 [openvswitch]
 ? ovs_ct_fill_key+0x1d/0x30 [openvswitch]
 ? ovs_flow_key_extract+0x2db/0x350 [openvswitch]
 ovs_vport_receive+0x77/0xd0 [openvswitch]
 ? __htab_map_lookup_elem+0x4e/0x60
 ? bpf_prog_680e8aff8547aec1_kfree+0x3b/0x714
 ? trace_call_bpf+0xc8/0x150
 ? kfree+0x1/0x250
 ? kfree+0x1/0x250
 ? kprobe_perf_func+0x4f/0x2b0
 ? kprobe_perf_func+0x4f/0x2b0
 ? __mod_memcg_lruvec_state+0x63/0xe0
 netdev_port_receive+0xc4/0x180 [openvswitch]
 ? netdev_port_receive+0x180/0x180 [openvswitch]
 netdev_frame_hook+0x1f/0x40 [openvswitch]
 __netif_receive_skb_core.constprop.0+0x23d/0xf00
 __netif_receive_skb_one_core+0x3f/0xa0
 __netif_receive_skb+0x15/0x60
 process_backlog+0x9e/0x170
 __napi_poll+0x33/0x180
 net_rx_action+0x126/0x280
 ? ttwu_do_activate+0x72/0xf0
 __do_softirq+0xd9/0x2e7
 ? rcu_report_exp_cpu_mult+0x1b0/0x1b0
 do_softirq+0x7d/0xb0
 &lt;/IRQ&gt;
 &lt;TASK&gt;
 __local_bh_enable_ip+0x54/0x60
 ip_finish_output2+0x191/0x460
 __ip_finish_output+0xb7/0x180
 ip_finish_output+0x2e/0xc0
 ip_output+0x78/0x100
 ? __ip_finish_output+0x180/0x180
 ip_local_out+0x5e/0x70
 __ip_queue_xmit+0x184/0x440
 ? tcp_syn_options+0x1f9/0x300
 ip_queue_xmit+0x15/0x20
 __tcp_transmit_skb+0x910/0x9c0
 ? __mod_memcg_state+0x44/0xa0
 tcp_connect+0x437/0x4e0
 ? ktime_get_with_offset+0x60/0xf0
 tcp_v4_connect+0x436/0x530
 __inet_stream_connect+0xd4/0x3a0
 ? kprobe_perf_func+0x4f/0x2b0
 ? aa_sk_perm+0x43/0x1c0
 inet_stream_connect+0x3b/0x60
 __sys_connect_file+0x63/0x70
 __sys_connect+0xa6/0xd0
 ? setfl+0x108/0x170
 ? do_fcntl+0xe8/0x5a0
 __x64_sys_connect+0x18/0x20
 do_syscall_64+0x5c/0xc0
 ? __x64_sys_fcntl+0xa9/0xd0
 ? exit_to_user_mode_prepare+0x37/0xb0
 ? syscall_exit_to_user_mode+0x27/0x50
 ? do_syscall_64+0x69/0xc0
 ? __sys_setsockopt+0xea/0x1e0
 ? exit_to_user_mode_prepare+0x37/0xb0
 ? syscall_exit_to_user_mode+0x27/0x50
 ? __x64_sys_setsockopt+0x1f/0x30
 ? do_syscall_64+0x69/0xc0
 ? irqentry_exit+0x1d/0x30
 ? exc_page_fault+0x89/0x170
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f7b8101c6a7
Code: 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 2a 00 00 00 0f 05 &lt;48&gt; 3d 00 f0 ff ff 77 51 c3 48 83 ec 18 89 54 24 0c 48 89 34 24 89
RSP: 002b:00007ffffd6b2198 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b8101c6a7
RDX: 0000000000000010 RSI: 00007ffffd6b2360 RDI: 0000000000000005
RBP: 0000561f1370d560 R08: 00002795ad21d1ac R09: 0030312e302e302e
R10: 00007ffffd73f080 R11: 0000000000000246 R12: 0000561f1370c410
R13: 0000000000000000 R14: 0000000000000005 R15: 0000000000000000
 &lt;/TASK&gt;

Fixes: 7f8a436eaa2c ("openvswitch: Add conntrack action")
Co-developed-by: Luca Czesla &lt;luca.czesla@mail.schwarz&gt;
Signed-off-by: Luca Czesla &lt;luca.czesla@mail.schwarz&gt;
Signed-off-by: Felix Huettner &lt;felix.huettner@mail.schwarz&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Reviewed-by: Simon Horman &lt;simon.horman@corigine.com&gt;
Link: https://lore.kernel.org/r/ZC0pBXBAgh7c76CA@kernel-bug-kernel-bug
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: don't let netpoll invoke NAPI if in xmit context</title>
<updated>2023-04-02T12:26:21+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-03-31T02:21:44+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=275b471e3d2daf1472ae8fa70dc1b50c9e0b9e75'/>
<id>275b471e3d2daf1472ae8fa70dc1b50c9e0b9e75</id>
<content type='text'>
Commit 0db3dc73f7a3 ("[NETPOLL]: tx lock deadlock fix") narrowed
down the region under netif_tx_trylock() inside netpoll_send_skb().
(At that point in time netif_tx_trylock() would lock all queues of
the device.) Taking the tx lock was problematic because driver's
cleanup method may take the same lock. So the change made us hold
the xmit lock only around xmit, and expected the driver to take
care of locking within -&gt;ndo_poll_controller().

Unfortunately this only works if netpoll isn't itself called with
the xmit lock already held. Netpoll code is careful and uses
trylock(). The drivers, however, may be using plain lock().
Printing while holding the xmit lock is going to result in rare
deadlocks.

Luckily we record the xmit lock owners, so we can scan all the queues,
the same way we scan NAPI owners. If any of the xmit locks is held
by the local CPU we better not attempt any polling.

It would be nice if we could narrow down the check to only the NAPIs
and the queue we're trying to use. I don't see a way to do that now.

Reported-by: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Fixes: 0db3dc73f7a3 ("[NETPOLL]: tx lock deadlock fix")
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit 0db3dc73f7a3 ("[NETPOLL]: tx lock deadlock fix") narrowed
down the region under netif_tx_trylock() inside netpoll_send_skb().
(At that point in time netif_tx_trylock() would lock all queues of
the device.) Taking the tx lock was problematic because driver's
cleanup method may take the same lock. So the change made us hold
the xmit lock only around xmit, and expected the driver to take
care of locking within -&gt;ndo_poll_controller().

Unfortunately this only works if netpoll isn't itself called with
the xmit lock already held. Netpoll code is careful and uses
trylock(). The drivers, however, may be using plain lock().
Printing while holding the xmit lock is going to result in rare
deadlocks.

Luckily we record the xmit lock owners, so we can scan all the queues,
the same way we scan NAPI owners. If any of the xmit locks is held
by the local CPU we better not attempt any polling.

It would be nice if we could narrow down the check to only the NAPIs
and the queue we're trying to use. I don't see a way to do that now.

Reported-by: Roman Gushchin &lt;roman.gushchin@linux.dev&gt;
Fixes: 0db3dc73f7a3 ("[NETPOLL]: tx lock deadlock fix")
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
Reviewed-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf</title>
<updated>2023-03-23T23:03:33+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-03-23T23:03:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=1b4ae19e432dfec785d980993c09593cbb182754'/>
<id>1b4ae19e432dfec785d980993c09593cbb182754</id>
<content type='text'>
Daniel Borkmann says:

====================
pull-request: bpf 2023-03-23

We've added 8 non-merge commits during the last 13 day(s) which contain
a total of 21 files changed, 238 insertions(+), 161 deletions(-).

The main changes are:

1) Fix verification issues in some BPF programs due to their stack usage
   patterns, from Eduard Zingerman.

2) Fix to add missing overflow checks in xdp_umem_reg and return an error
   in such case, from Kal Conley.

3) Fix and undo poisoning of strlcpy in libbpf given it broke builds for
   libcs which provided the former like uClibc-ng, from Jesus Sanchez-Palencia.

4) Fix insufficient bpf_jit_limit default to avoid users running into hard
   to debug seccomp BPF errors, from Daniel Borkmann.

5) Fix driver return code when they don't support a bpf_xdp_metadata kfunc
   to make it unambiguous from other errors, from Jesper Dangaard Brouer.

6) Two BPF selftest fixes to address compilation errors from recent changes
   in kernel structures, from Alexei Starovoitov.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver support
  bpf: Adjust insufficient default bpf_jit_limit
  xsk: Add missing overflow check in xdp_umem_reg
  selftests/bpf: Fix progs/test_deny_namespace.c issues.
  selftests/bpf: Fix progs/find_vma_fail1.c build error.
  libbpf: Revert poisoning of strlcpy
  selftests/bpf: Tests for uninitialized stack reads
  bpf: Allow reads from uninit stack
====================

Link: https://lore.kernel.org/r/20230323225221.6082-1-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>
Daniel Borkmann says:

====================
pull-request: bpf 2023-03-23

We've added 8 non-merge commits during the last 13 day(s) which contain
a total of 21 files changed, 238 insertions(+), 161 deletions(-).

The main changes are:

1) Fix verification issues in some BPF programs due to their stack usage
   patterns, from Eduard Zingerman.

2) Fix to add missing overflow checks in xdp_umem_reg and return an error
   in such case, from Kal Conley.

3) Fix and undo poisoning of strlcpy in libbpf given it broke builds for
   libcs which provided the former like uClibc-ng, from Jesus Sanchez-Palencia.

4) Fix insufficient bpf_jit_limit default to avoid users running into hard
   to debug seccomp BPF errors, from Daniel Borkmann.

5) Fix driver return code when they don't support a bpf_xdp_metadata kfunc
   to make it unambiguous from other errors, from Jesper Dangaard Brouer.

6) Two BPF selftest fixes to address compilation errors from recent changes
   in kernel structures, from Alexei Starovoitov.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver support
  bpf: Adjust insufficient default bpf_jit_limit
  xsk: Add missing overflow check in xdp_umem_reg
  selftests/bpf: Fix progs/test_deny_namespace.c issues.
  selftests/bpf: Fix progs/find_vma_fail1.c build error.
  libbpf: Revert poisoning of strlcpy
  selftests/bpf: Tests for uninitialized stack reads
  bpf: Allow reads from uninit stack
====================

Link: https://lore.kernel.org/r/20230323225221.6082-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xdp: bpf_xdp_metadata use EOPNOTSUPP for no driver support</title>
<updated>2023-03-22T16:11:09+00:00</updated>
<author>
<name>Jesper Dangaard Brouer</name>
<email>brouer@redhat.com</email>
</author>
<published>2023-03-21T13:52:31+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=915efd8a446b74442039d31689d5d863caf82517'/>
<id>915efd8a446b74442039d31689d5d863caf82517</id>
<content type='text'>
When driver doesn't implement a bpf_xdp_metadata kfunc the fallback
implementation returns EOPNOTSUPP, which indicate device driver doesn't
implement this kfunc.

Currently many drivers also return EOPNOTSUPP when the hint isn't
available, which is ambiguous from an API point of view. Instead
change drivers to return ENODATA in these cases.

There can be natural cases why a driver doesn't provide any hardware
info for a specific hint, even on a frame to frame basis (e.g. PTP).
Lets keep these cases as separate return codes.

When describing the return values, adjust the function kernel-doc layout
to get proper rendering for the return values.

Fixes: ab46182d0dcb ("net/mlx4_en: Support RX XDP metadata")
Fixes: bc8d405b1ba9 ("net/mlx5e: Support RX XDP metadata")
Fixes: 306531f0249f ("veth: Support RX XDP metadata")
Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Tariq Toukan &lt;tariqt@nvidia.com&gt;
Link: https://lore.kernel.org/r/167940675120.2718408.8176058626864184420.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When driver doesn't implement a bpf_xdp_metadata kfunc the fallback
implementation returns EOPNOTSUPP, which indicate device driver doesn't
implement this kfunc.

Currently many drivers also return EOPNOTSUPP when the hint isn't
available, which is ambiguous from an API point of view. Instead
change drivers to return ENODATA in these cases.

There can be natural cases why a driver doesn't provide any hardware
info for a specific hint, even on a frame to frame basis (e.g. PTP).
Lets keep these cases as separate return codes.

When describing the return values, adjust the function kernel-doc layout
to get proper rendering for the return values.

Fixes: ab46182d0dcb ("net/mlx4_en: Support RX XDP metadata")
Fixes: bc8d405b1ba9 ("net/mlx5e: Support RX XDP metadata")
Fixes: 306531f0249f ("veth: Support RX XDP metadata")
Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Signed-off-by: Jesper Dangaard Brouer &lt;brouer@redhat.com&gt;
Acked-by: Stanislav Fomichev &lt;sdf@google.com&gt;
Acked-by: Toke Høiland-Jørgensen &lt;toke@redhat.com&gt;
Acked-by: Tariq Toukan &lt;tariqt@nvidia.com&gt;
Link: https://lore.kernel.org/r/167940675120.2718408.8176058626864184420.stgit@firesoul
Signed-off-by: Alexei Starovoitov &lt;ast@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: xdp: don't call notifiers during driver init</title>
<updated>2023-03-17T04:33:08+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-03-16T22:02:34+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=769639c1fe8a98129aa97c8ee981639db1e8955c'/>
<id>769639c1fe8a98129aa97c8ee981639db1e8955c</id>
<content type='text'>
Drivers will commonly perform feature setting during init, if they use
the xdp_set_features_flag() helper they'll likely run into an ASSERT_RTNL()
inside call_netdevice_notifiers_info().

Don't call the notifier until the device is actually registered.
Nothing should be tracking the device until its registered and
after its unregistration has started.

Fixes: 4d5ab0ad964d ("net/mlx5e: take into account device reconfiguration for xdp_features flag")
Link: https://lore.kernel.org/r/20230316220234.598091-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Drivers will commonly perform feature setting during init, if they use
the xdp_set_features_flag() helper they'll likely run into an ASSERT_RTNL()
inside call_netdevice_notifiers_info().

Don't call the notifier until the device is actually registered.
Nothing should be tracking the device until its registered and
after its unregistration has started.

Fixes: 4d5ab0ad964d ("net/mlx5e: take into account device reconfiguration for xdp_features flag")
Link: https://lore.kernel.org/r/20230316220234.598091-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>ynl: broaden the license even more</title>
<updated>2023-03-17T04:20:32+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-03-15T23:03:50+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=4e16b6a748df52800c90f3ab181aef8129bd332f'/>
<id>4e16b6a748df52800c90f3ab181aef8129bd332f</id>
<content type='text'>
I relicensed Netlink spec code to GPL-2.0 OR BSD-3-Clause but
we still put a slightly different license on the uAPI header
than the rest of the code. Use the Linux-syscall-note on all
the specs and all generated code. It's moot for kernel code,
but should not hurt. This way the licenses match everywhere.

Cc: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Fixes: 37d9df224d1e ("ynl: re-license uniformly under GPL-2.0 OR BSD-3-Clause")
Reviewed-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
I relicensed Netlink spec code to GPL-2.0 OR BSD-3-Clause but
we still put a slightly different license on the uAPI header
than the rest of the code. Use the Linux-syscall-note on all
the specs and all generated code. It's moot for kernel code,
but should not hurt. This way the licenses match everywhere.

Cc: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Fixes: 37d9df224d1e ("ynl: re-license uniformly under GPL-2.0 OR BSD-3-Clause")
Reviewed-by: Chuck Lever &lt;chuck.lever@oracle.com&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>xdp: add xdp_set_features_flag utility routine</title>
<updated>2023-03-11T05:33:47+00:00</updated>
<author>
<name>Lorenzo Bianconi</name>
<email>lorenzo@kernel.org</email>
</author>
<published>2023-03-09T12:25:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=f85949f98206b3b11d92d695cea4efda6a81f00e'/>
<id>f85949f98206b3b11d92d695cea4efda6a81f00e</id>
<content type='text'>
Introduce xdp_set_features_flag utility routine in order to update
dynamically xdp_features according to the dynamic hw configuration via
ethtool (e.g. changing number of hw rx/tx queues).
Add xdp_clear_features_flag() in order to clear all xdp_feature flag.

Reviewed-by: Shay Agroskin &lt;shayagr@amazon.com&gt;
Signed-off-by: Lorenzo Bianconi &lt;lorenzo@kernel.org&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Introduce xdp_set_features_flag utility routine in order to update
dynamically xdp_features according to the dynamic hw configuration via
ethtool (e.g. changing number of hw rx/tx queues).
Add xdp_clear_features_flag() in order to clear all xdp_feature flag.

Reviewed-by: Shay Agroskin &lt;shayagr@amazon.com&gt;
Signed-off-by: Lorenzo Bianconi &lt;lorenzo@kernel.org&gt;
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
