CVE-2023-53188
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2023-53188
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2023-53188.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2023-53188
- Downstream
- Published
- 2025-09-15T14:04:52.248Z
- Modified
- 2025-11-30T06:34:53.235023Z
- Summary
- net: openvswitch: fix race on port output
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
net: openvswitch: fix race on port output
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_notifysomewhere in the process 2. this sets firstNETREG_UNREGISTERINGon both ends of the veth and then runssynchronize_net3. it then callscall_netdevice_notifierswithNETDEV_UNREGISTER4. this is then handled bydp_device_eventwhich callsovs_netdev_detach_dev(if a vport is found, which is the case for the veth interface attached to ovs) 5. this removes the rxhandlers of the device but does not prevent packages to be sent to the device 6.dp_device_eventthen queues the vport deletion to work in background as a ovslock is needed that we do not hold in the unregistration path 7.unregister_netdevice_many_notifycontinues to callnetdev_unregister_kobjectwhich setsreal_num_tx_queuesto 0 8. port deletion continues (but details are not relevant for this issue) 9. at some future point the background task deletes the vportIf 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_xmitflow even though the device is unregistering. Inskb_tx_hash(which is called in thedev_queue_xmit) path there is a while loop (if the packet has a rx_queue recorded) that is infinite ifdev->real_num_tx_queuesis zero.To prevent this from happening we update
do_outputto 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_hashif we will hit the infinite loop.bpftrace (first word is function name):
_devqueuexmit server: realnumtxqueues: 1, cpu: 2, pid: 28024, tid: 28024, skbaddr: 0xffff9edb6f207000, regstate: 1 netdevcorepicktx server: addr: 0xffff9f0a46d4a000 realnumtxqueues: 1, cpu: 2, pid: 28024, tid: 28024, skbaddr: 0xffff9edb6f207000, regstate: 1 dpdeviceevent server: realnumtxqueues: 1 cpu 9, pid: 21024, tid: 21024, event 2, regstate: 1 synchronizercuexpedited: cpu 9, pid: 21024, tid: 21024 synchronizercuexpedited: cpu 9, pid: 21024, tid: 21024 synchronizercuexpedited: cpu 9, pid: 21024, tid: 21024 synchronizercuexpedited: cpu 9, pid: 21024, tid: 21024 dpdeviceevent server: realnumtxqueues: 1 cpu 9, pid: 21024, tid: 21024, event 6, regstate: 2 ovsnetdevdetachdev server: realnumtxqueues: 1 cpu 9, pid: 21024, tid: 21024, regstate: 2 netdevrxhandlerunregister server: realnumtxqueues: 1, cpu: 9, pid: 21024, tid: 21024, regstate: 2 synchronizercuexpedited: cpu 9, pid: 21024, tid: 21024 netdevrxhandlerunregister ret server: realnumtxqueues: 1, cpu: 9, pid: 21024, tid: 21024, regstate: 2 dp ---truncated---
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53188.json" }- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/066b86787fa3d97b7aefb5ac0a99a22dad2d15f8
- https://git.kernel.org/stable/c/284be5db6c8d06d247ed056cfc448c4f79bbb16c
- https://git.kernel.org/stable/c/56252da41426f3d01957456f13caf46ce670ea29
- https://git.kernel.org/stable/c/5efcb301523baacd98a47553d4996e924923114d
- https://git.kernel.org/stable/c/644b3051b06ba465bc7401bfae9b14963cbc8c1c
- https://git.kernel.org/stable/c/9b0dd09c1ceb35950d2884848099fccc9ec9a123
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/53xxx/CVE-2023-53188.json
- https://nvd.nist.gov/vuln/detail/CVE-2023-53188
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced7f8a436eaa2c3ddd8e1ff2fbca267e6275085536Fixed9b0dd09c1ceb35950d2884848099fccc9ec9a123Fixed284be5db6c8d06d247ed056cfc448c4f79bbb16cFixed5efcb301523baacd98a47553d4996e924923114dFixed644b3051b06ba465bc7401bfae9b14963cbc8c1cFixed56252da41426f3d01957456f13caf46ce670ea29Fixed066b86787fa3d97b7aefb5ac0a99a22dad2d15f8