# CVE-2025-71091: team: fix check for port enabled in team_queue_override_port_prio_changed()

> A use-after-free vulnerability in the Linux kernel team driver allows local attackers to cause a system crash via list corruption.

- **Severity:** High 7.8 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Any signed-in user
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 13 Jan 2026
- **Updated:** 19 Oct 2026
- **Also known as:** BELL-CVE-2025-71091, DEBIAN-CVE-2025-71091, GHSA-34rx-7455-xg2h, ROOT-OS-DEBIAN-11-CVE-2025-71091, ROOT-OS-DEBIAN-12-CVE-2025-71091, ROOT-OS-DEBIAN-13-CVE-2025-71091, ROOT-OS-UBUNTU-2204-CVE-2025-71091, ROOT-OS-UBUNTU-2404-CVE-2025-71091, UBUNTU-CVE-2025-71091

## What is CVE-2025-71091?

CVE-2025-71091 is a high-severity use after free vulnerability in Linux kernel, published on 13 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

In the Linux kernel, the following vulnerability has been resolved:

team: fix check for port enabled in team_queue_override_port_prio_changed()

There has been a syzkaller bug reported recently with the following
trace:

list_del corruption, ffff888058bea080->prev is LIST_POISON2 (dead000000000122)
------------[ cut here ]------------
kernel BUG at lib/list_debug.c:59!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
CPU: 3 UID: 0 PID: 21246 Comm: syz.0.2928 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:__list_del_entry_valid_or_report+0x13e/0x200 lib/list_debug.c:59
Code: 48 c7 c7 e0 71 f0 8b e8 30 08 ef fc 90 0f 0b 48 89 ef e8 a5 02 55 fd 48 89 ea 48 89 de 48 c7 c7 40 72 f0 8b e8 13 08 ef fc 90 <0f> 0b 48 89 ef e8 88 02 55 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff
RSP: 0018:ffffc9000d49f370 EFLAGS: 00010286
RAX: 000000000000004e RBX: ffff888058bea080 RCX: ffffc9002817d000
RDX: 0000000000000000 RSI: ffffffff819becc6 RDI: 0000000000000005
RBP: dead000000000122 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffff888039e9c230
R13: ffff888058bea088 R14: ffff888058bea080 R15: ffff888055461480
FS:  00007fbbcfe6f6c0(0000) GS:ffff8880d6d0a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3afcb0 CR3: 00000000382c7000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __list_del_entry_valid include/linux/list.h:132 [inline]
 __list_del_entry include/linux/list.h:223 [inline]
 list_del_rcu include/linux/rculist.h:178 [inline]
 __team_queue_override_port_del drivers/net/team/team_core.c:826 [inline]
 __team_queue_override_port_del drivers/net/team/team_core.c:821 [inline]
 team_queue_override_port_prio_changed drivers/net/team/team_core.c:883 [inline]
 team_priority_option_set+0x171/0x2f0 drivers/net/team/team_core.c:1534
 team_option_set drivers/net/team/team_core.c:376 [inline]
 team_nl_options_set_doit+0x8ae/0xe60 drivers/net/team/team_core.c:2653
 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115
 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
 genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210
 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630
 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684
 __sys_sendmsg+0x16d/0x220 net/socket.c:2716
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The problem is in this flow:
1) Port is enabled, queue_id != 0, in qom_list
2) Port gets disabled
        -> team_port_disable()
        -> team_queue_override_port_del()
        -> del (removed from list)
3) Port is disabled, queue_id != 0, not in any list
4) Priority changes
        -> team_queue_override_port_prio_changed()
        -> checks: port disabled && queue_id != 0
        -> calls del - hits the BUG as it is removed already

To fix this, change the check in team_queue_override_port_prio_changed()
so it returns early if port is not enabled.

Weakness: CWE-416 (Use After Free)

## Which versions are affected by CVE-2025-71091?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2025-71091?

Apply the vendor's patch.

## Is CVE-2025-71091 being exploited?

There is no known exploitation of CVE-2025-71091 in the wild and no public exploit code.

## Other vulnerabilities in Linux kernel

- [CVE-2026-53266](https://insights.sbomify.com/CVE-2026-53266/): Linux Kernel Out-of-Bounds Write (high 8.8, exploited in the wild)
- [CVE-2013-6282](https://insights.sbomify.com/CVE-2013-6282/): Linux Kernel Improper Input Validation (high 8.8, exploited in the wild)
- [CVE-2022-0185](https://insights.sbomify.com/CVE-2022-0185/): Linux Kernel Heap-Based Buffer Overflow (high 8.4, exploited in the wild)
- [CVE-2013-2094](https://insights.sbomify.com/CVE-2013-2094/): Linux Kernel Privilege Escalation (high 8.4, exploited in the wild)
- [CVE-2026-53362](https://insights.sbomify.com/CVE-2026-53362/): Linux Kernel Unspecified (high 7.8, exploited in the wild)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2025-71091 and fix it if it is affected.

What it is: CVE-2025-71091 is a high-severity use after free vulnerability in Linux kernel, published on 13 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2025-71091 in the wild and no public exploit code.

Affected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2025-71091/ (Markdown: https://insights.sbomify.com/CVE-2025-71091/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2025-71091
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2025-71091
- OSV: https://osv.dev/vulnerability/CVE-2025-71091

---
From sbomify Insights: https://insights.sbomify.com/CVE-2025-71091/
Summaries are generated and may contain mistakes; the official description above is the record.