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7.8
CVE-2025-38146: Linux OpenVSwitch: Unexpected MPLS Packets Can Cause System Freeze
CVE-2025-38146
Summary
A fix has been applied to the Linux OpenVSwitch to prevent a system freeze when it encounters an unexpected Multi-Protocol Label Switching (MPLS) packet. This issue could cause a system to become unresponsive, but the fix addresses the problem. System administrators should update their OpenVSwitch to the latest version to ensure they have the latest security patches.
What to do
No fix is available yet. Check with your software vendor for updates.
Affected software
| Vendor | Product | Affected versions |
|---|---|---|
| linux | linux_kernel |
>= 5.5, < 5.10.239 >= 5.11, < 5.15.186 >= 5.16, < 6.1.142 >= 6.2, < 6.6.94 >= 6.7, < 6.12.34 >= 6.13, < 6.15.3 cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| debian | debian_linux |
11.0 cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* |
Original title
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 ther...
Original 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>
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>
nvd CVSS3.1
7.8
Vulnerability type
CWE-129
- https://git.kernel.org/stable/c/0bdc924bfb319fb10d1113cbf091fc26fb7b1f99 Patch
- https://git.kernel.org/stable/c/3c1906a3d50cb94fd0a10e97a1c0a40c0f033cb7 Patch
- https://git.kernel.org/stable/c/4b9a086eedc1fddae632310386098c12155e3d0a Patch
- https://git.kernel.org/stable/c/69541e58323ec3e3904e1fa87a6213961b1f52f4 Patch
- https://git.kernel.org/stable/c/8ebcd311b4866ab911d1445ead08690e67f0c488 Patch
- https://git.kernel.org/stable/c/ad17eb86d042d72a59fd184ad1adf34f5eb36843 Patch
- https://git.kernel.org/stable/c/f26fe7c3002516dd3c288f1012786df31f4d89e0 Patch
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html Third Party Advisory
Published: 3 Jul 2025 · Updated: 20 Jul 2026 · First seen: 7 Mar 2026