OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb
length in OVS_CB(skb)->cutlen. When a later userspace action segments a
GSO skb, queue_gso_packets() reuses that delta for each smaller segment.
A segment can then reach queue_userspace_packet() with cutlen greater
than skb->len, underflowing the length passed to skb_zerocopy().
Store the maximum preserved length instead and bound each consumer
against the current skb length. Use U32_MAX as the no-truncation
sentinel so the value remains valid if skb geometry changes before a
consumer handles it.
Fixes: f2a4d086ed ("openvswitch: Add packet truncation support.")
Cc: stable@vger.kernel.org
Assisted-by: Codex:gpt-5.5
Signed-off-by: Kyle Zeng <kylebot@openai.com>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20260707221635.27489-1-kylebot@openai.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
After the patch in the "Fixes" tag, the allocation of the "reply" skb
can happen either before or after locking the ovs_mutex.
However, error cleanups still follow the classical reversed order,
assuming "reply" is allocated before locking: it is freed after unlocking.
If "reply" allocation happens after locking the mutex and it fails,
"reply" is left with an ERR_PTR, and execution jumps to the correspondent
cleanup stage which will try to free an invalid pointer.
Fix this by setting the pointer to NULL after having saved its error
value.
Fixes: 893f139b9a ("openvswitch: Minimize ovs_flow_cmd_new|set critical sections.")
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://patch.msgid.link/20260604121946.942164-1-amorenoz@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The vport netlink reply helpers allocate a fixed-size skb with
nlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID
array via ovs_vport_get_upcall_portids(). Since
ovs_vport_set_upcall_portids() accepts any non-zero multiple of
sizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID
array large enough to overflow the reply buffer, causing nla_put() to
fail with -EMSGSIZE and hitting BUG_ON(err < 0). On systems with
unprivileged user namespaces enabled (e.g., Ubuntu default), this is
reachable via unshare -Urn since OVS vport mutation operations use
GENL_UNS_ADMIN_PERM.
kernel BUG at net/openvswitch/datapath.c:2414!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1
RIP: 0010:ovs_vport_cmd_set+0x34c/0x400
Call Trace:
<TASK>
genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)
genl_rcv_msg (net/netlink/genetlink.c:1194)
netlink_rcv_skb (net/netlink/af_netlink.c:2550)
genl_rcv (net/netlink/genetlink.c:1219)
netlink_unicast (net/netlink/af_netlink.c:1344)
netlink_sendmsg (net/netlink/af_netlink.c:1894)
__sys_sendto (net/socket.c:2206)
__x64_sys_sendto (net/socket.c:2209)
do_syscall_64 (arch/x86/entry/syscall_64.c:63)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
</TASK>
Kernel panic - not syncing: Fatal exception
Reject attempts to set more PIDs than nr_cpu_ids in
ovs_vport_set_upcall_portids(), and pre-compute the worst-case reply
size in ovs_vport_cmd_msg_size() based on that bound, similar to the
existing ovs_dp_cmd_msg_size(). nr_cpu_ids matches the cap already
used by the per-CPU dispatch configuration on the datapath side
(ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the
two sides stay consistent.
Fixes: 5cd667b0a4 ("openvswitch: Allow each vport to have an array of 'port_id's.")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260416024653.153456-2-bestswngs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
When a packet enters OVS datapath and there is no flow to handle it,
packet goes to userspace through a MISS upcall. With per-CPU upcall
dispatch mechanism, we're using the current CPU id to select the
Netlink PID on which to send this packet. This allows us to send
packets from the same traffic flow through the same handler.
The handler will process the packet, install required flow into the
kernel and re-inject the original packet via OVS_PACKET_CMD_EXECUTE.
While handling OVS_PACKET_CMD_EXECUTE, however, we may hit a
recirculation action that will pass the (likely modified) packet
through the flow lookup again. And if the flow is not found, the
packet will be sent to userspace again through another MISS upcall.
However, the handler thread in userspace is likely running on a
different CPU core, and the OVS_PACKET_CMD_EXECUTE request is handled
in the syscall context of that thread. So, when the time comes to
send the packet through another upcall, the per-CPU dispatch will
choose a different Netlink PID, and this packet will end up processed
by a different handler thread on a different CPU.
The process continues as long as there are new recirculations, each
time the packet goes to a different handler thread before it is sent
out of the OVS datapath to the destination port. In real setups the
number of recirculations can go up to 4 or 5, sometimes more.
There is always a chance to re-order packets while processing upcalls,
because userspace will first install the flow and then re-inject the
original packet. So, there is a race window when the flow is already
installed and the second packet can match it and be forwarded to the
destination before the first packet is re-injected. But the fact that
packets are going through multiple upcalls handled by different
userspace threads makes the reordering noticeably more likely, because
we not only have a race between the kernel and a userspace handler
(which is hard to avoid), but also between multiple userspace handlers.
For example, let's assume that 10 packets got enqueued through a MISS
upcall for handler-1, it will start processing them, will install the
flow into the kernel and start re-injecting packets back, from where
they will go through another MISS to handler-2. Handler-2 will install
the flow into the kernel and start re-injecting the packets, while
handler-1 continues to re-inject the last of the 10 packets, they will
hit the flow installed by handler-2 and be forwarded without going to
the handler-2, while handler-2 still re-injects the first of these 10
packets. Given multiple recirculations and misses, these 10 packets
may end up completely mixed up on the output from the datapath.
Let's allow userspace to specify on which Netlink PID the packets
should be upcalled while processing OVS_PACKET_CMD_EXECUTE.
This makes it possible to ensure that all the packets are processed
by the same handler thread in the userspace even with them being
upcalled multiple times in the process. Packets will remain in order
since they will be enqueued to the same socket and re-injected in the
same order. This doesn't eliminate re-ordering as stated above, since
we still have a race between kernel and the userspace thread, but it
allows to eliminate races between multiple userspace threads.
Userspace knows the PID of the socket on which the original upcall is
received, so there is no need to send it up from the kernel.
Solution requires storing the value somewhere for the duration of the
packet processing. There are two potential places for this: our skb
extension or the per-CPU storage. It's not clear which is better,
so just following currently used scheme of storing this kind of things
along the skb. We still have a decent amount of space in the cb.
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Flavio Leitner <fbl@sysclose.org>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20250702155043.2331772-1-i.maximets@ovn.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
PERCPU_MODULE_RESERVE defines the maximum size that can by used for the
per-CPU data size used by modules. This is 8KiB.
Commit 035fcdc4d2 ("openvswitch: Merge three per-CPU structures into
one") restructured the per-CPU memory allocation for the module and
moved the separate alloc_percpu() invocations at module init time to a
static per-CPU variable which is allocated by the module loader.
The size of the per-CPU data section for openvswitch is 6488 bytes which
is ~80% of the available per-CPU memory. Together with a few other
modules it is easy to exhaust the available 8KiB of memory.
Allocate ovs_pcpu_storage dynamically at module init time.
Reported-by: Gal Pressman <gal@nvidia.com>
Closes: https://lore.kernel.org/all/c401e017-f8db-4f57-a1cd-89beb979a277@nvidia.com
Fixes: 035fcdc4d2 ("openvswitch: Merge three per-CPU structures into one")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20250613123629.-XSoQTCu@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
ovs_pcpu_storage is a per-CPU variable and relies on disabled BH for its
locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT
this data structure requires explicit locking.
The data structure can be referenced recursive and there is a recursion
counter to avoid too many recursions.
Add a local_lock_t to the data structure and use
local_lock_nested_bh() for locking. Add an owner of the struct which is
the current task and acquire the lock only if the structure is not owned
by the current task.
Cc: Aaron Conole <aconole@redhat.com>
Cc: Eelco Chaudron <echaudro@redhat.com>
Cc: Ilya Maximets <i.maximets@ovn.org>
Cc: dev@openvswitch.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20250512092736.229935-9-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Most of the original conversion is from the spatch below,
but I edited some and left out other instances that were
either buggy after conversion (where default values don't
fit into the type) or just looked strange.
@@
expression attr, def;
expression val;
identifier fn =~ "^nla_get_.*";
fresh identifier dfn = fn ## "_default";
@@
(
-if (attr)
- val = fn(attr);
-else
- val = def;
+val = dfn(attr, def);
|
-if (!attr)
- val = def;
-else
- val = fn(attr);
+val = dfn(attr, def);
|
-if (!attr)
- return def;
-return fn(attr);
+return dfn(attr, def);
|
-attr ? fn(attr) : def
+dfn(attr, def)
|
-!attr ? def : fn(attr)
+dfn(attr, def)
)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@kernel.org>
Link: https://patch.msgid.link/20241108114145.0580b8684e7f.I740beeaa2f70ebfc19bfca1045a24d6151992790@changeid
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
There is something wrong with ovs_drop_reasons. ovs_drop_reasons[0] is
"OVS_DROP_LAST_ACTION", but OVS_DROP_LAST_ACTION == __OVS_DROP_REASON + 1,
which means that ovs_drop_reasons[1] should be "OVS_DROP_LAST_ACTION".
And as Adrian tested, without the patch, adding flow to drop packets
results in:
drop at: do_execute_actions+0x197/0xb20 [openvsw (0xffffffffc0db6f97)
origin: software
input port ifindex: 8
timestamp: Tue Aug 20 10:19:17 2024 859853461 nsec
protocol: 0x800
length: 98
original length: 98
drop reason: OVS_DROP_ACTION_ERROR
With the patch, the same results in:
drop at: do_execute_actions+0x197/0xb20 [openvsw (0xffffffffc0db6f97)
origin: software
input port ifindex: 8
timestamp: Tue Aug 20 10:16:13 2024 475856608 nsec
protocol: 0x800
length: 98
original length: 98
drop reason: OVS_DROP_LAST_ACTION
Fix this by initializing ovs_drop_reasons with index.
Fixes: 9d802da40b ("net: openvswitch: add last-action drop reason")
Signed-off-by: Menglong Dong <dongml2@chinatelecom.cn>
Tested-by: Adrian Moreno <amorenoz@redhat.com>
Reviewed-by: Adrian Moreno <amorenoz@redhat.com>
Link: https://patch.msgid.link/20240821123252.186305-1-dongml2@chinatelecom.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
genetlink.h is a shell of what used to be a combined uAPI
and kernel header over a decade ago. It has fewer than
10 lines of code. Merge it into net/genetlink.h.
In some ways it'd be better to keep the combined header
under linux/ but it would make looking through git history
harder.
Acked-by: Sven Eckelmann <sven@narfation.org>
Link: https://lore.kernel.org/r/20240329175710.291749-4-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Recent changes in net-next (commit 759ab1edb5 ("net: store netdevs
in an xarray")) refactored the handling of pre-assigned ifindexes
and let syzbot surface a latent problem in ovs. ovs does not validate
ifindex, making it possible to create netdev ports with negative
ifindex values. It's easy to repro with YNL:
$ ./cli.py --spec netlink/specs/ovs_datapath.yaml \
--do new \
--json '{"upcall-pid": 1, "name":"my-dp"}'
$ ./cli.py --spec netlink/specs/ovs_vport.yaml \
--do new \
--json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}'
$ ip link show
-65536: some-port0: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff
...
Validate the inputs. Now the second command correctly returns:
$ ./cli.py --spec netlink/specs/ovs_vport.yaml \
--do new \
--json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}'
lib.ynl.NlError: Netlink error: Numerical result out of range
nl_len = 108 (92) nl_flags = 0x300 nl_type = 2
error: -34 extack: {'msg': 'integer out of range', 'unknown': [[type:4 len:36] b'\x0c\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x03\x00\xff\xff\xff\x7f\x00\x00\x00\x00\x08\x00\x01\x00\x08\x00\x00\x00'], 'bad-attr': '.ifindex'}
Accept 0 since it used to be silently ignored.
Fixes: 54c4ef34c4 ("openvswitch: allow specifying ifindex of new interfaces")
Reported-by: syzbot+7456b5dcf65111553320@syzkaller.appspotmail.com
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://lore.kernel.org/r/20230814203840.2908710-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Create a new drop reason subsystem for openvswitch and add the first
drop reason to represent last-action drops.
Last-action drops happen when a flow has an empty action list or there
is no action that consumes the packet (output, userspace, recirc, etc).
It is the most common way in which OVS drops packets.
Implementation-wise, most of these skb-consuming actions already call
"consume_skb" internally and return directly from within the
do_execute_actions() loop so with minimal changes we can assume that
any skb that exits the loop normally is a packet drop.
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.
Here is an example:
PID: 59693 TASK: ffff0005f4f51500 CPU: 0 COMMAND: "ovs-vswitchd"
#0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
#1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
#2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
#3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
#4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
#5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
#6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
#7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
...
PID: 58682 TASK: ffff0005b2f0bf00 CPU: 0 COMMAND: "kworker/0:3"
#0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
#1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
#2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
#3 [ffff80000a5d3120] die at ffffb70f0628234c
#4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
#5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
#6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
#7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
#8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
#9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
#10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
#11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
#12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
#13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
#14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
#15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
#16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
#17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90
We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.
Fixes: 95637d91fe ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea365a ("net: openvswitch: Add support to count upcall packets")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit mentioned below causes the ovs_flow_tbl_lookup() function
to be called with the masked key. However, it's supposed to be called
with the unmasked key. This due to the fact that the datapath supports
installing wider flows, and OVS relies on this behavior. For example
if ipv4(src=1.1.1.1/192.0.0.0, dst=1.1.1.2/192.0.0.0) exists, a wider
flow (smaller mask) of ipv4(src=192.1.1.1/128.0.0.0,dst=192.1.1.2/
128.0.0.0) is allowed to be added.
However, if we try to add a wildcard rule, the installation fails:
$ ovs-appctl dpctl/add-flow system@myDP "in_port(1),eth_type(0x0800), \
ipv4(src=1.1.1.1/192.0.0.0,dst=1.1.1.2/192.0.0.0,frag=no)" 2
$ ovs-appctl dpctl/add-flow system@myDP "in_port(1),eth_type(0x0800), \
ipv4(src=192.1.1.1/0.0.0.0,dst=49.1.1.2/0.0.0.0,frag=no)" 2
ovs-vswitchd: updating flow table (File exists)
The reason is that the key used to determine if the flow is already
present in the system uses the original key ANDed with the mask.
This results in the IP address not being part of the (miniflow) key,
i.e., being substituted with an all-zero value. When doing the actual
lookup, this results in the key wrongfully matching the first flow,
and therefore the flow does not get installed.
This change reverses the commit below, but rather than having the key
on the stack, it's allocated.
Fixes: 190aa3e778 ("openvswitch: Fix Frame-size larger than 1024 bytes warning.")
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Add support to count upall packets, when kmod of openvswitch
upcall to count the number of packets for upcall succeed and
failed, which is a better way to see how many packets upcalled
on every interfaces.
Signed-off-by: wangchuanlei <wangchuanlei@inspur.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
