# CVE-2024-49980: vrf: revert "vrf: Remove unnecessary RCU-bh critical section"

> A race condition in the Linux kernel VRF module can cause a deadlock, leading to a denial of service.

- **Severity:** Medium 5.5 (`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/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:** 21 Oct 2024
- **Updated:** 11 May 2026
- **Also known as:** BELL-CVE-2024-49980, DEBIAN-CVE-2024-49980, GHSA-h72j-469c-c787, UBUNTU-CVE-2024-49980

## What is CVE-2024-49980?

CVE-2024-49980 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 2024. 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:

vrf: revert "vrf: Remove unnecessary RCU-bh critical section"

This reverts commit 504fc6f4f7f681d2a03aa5f68aad549d90eab853.

dev_queue_xmit_nit is expected to be called with BH disabled.
__dev_queue_xmit has the following:

        /* Disable soft irqs for various locks below. Also
         * stops preemption for RCU.
         */
        rcu_read_lock_bh();

VRF must follow this invariant. The referenced commit removed this
protection. Which triggered a lockdep warning:

	================================
	WARNING: inconsistent lock state
	6.11.0 #1 Tainted: G        W
	--------------------------------
	inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
	btserver/134819 [HC0[0]:SC0[0]:HE1:SE1] takes:
	ffff8882da30c118 (rlock-AF_PACKET){+.?.}-{2:2}, at: tpacket_rcv+0x863/0x3b30
	{IN-SOFTIRQ-W} state was registered at:
	  lock_acquire+0x19a/0x4f0
	  _raw_spin_lock+0x27/0x40
	  packet_rcv+0xa33/0x1320
	  __netif_receive_skb_core.constprop.0+0xcb0/0x3a90
	  __netif_receive_skb_list_core+0x2c9/0x890
	  netif_receive_skb_list_internal+0x610/0xcc0
          [...]

	other info that might help us debug this:
	 Possible unsafe locking scenario:

	       CPU0
	       ----
	  lock(rlock-AF_PACKET);
	  <Interrupt>
	    lock(rlock-AF_PACKET);

	 *** DEADLOCK ***

	Call Trace:
	 <TASK>
	 dump_stack_lvl+0x73/0xa0
	 mark_lock+0x102e/0x16b0
	 __lock_acquire+0x9ae/0x6170
	 lock_acquire+0x19a/0x4f0
	 _raw_spin_lock+0x27/0x40
	 tpacket_rcv+0x863/0x3b30
	 dev_queue_xmit_nit+0x709/0xa40
	 vrf_finish_direct+0x26e/0x340 [vrf]
	 vrf_l3_out+0x5f4/0xe80 [vrf]
	 __ip_local_out+0x51e/0x7a0
          [...]

Weakness: CWE-667 (Improper Locking)

## Which versions are affected by CVE-2024-49980?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-49980?

Apply the vendor's patch.

## Is CVE-2024-49980 being exploited?

There is no known exploitation of CVE-2024-49980 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-2024-49980 and fix it if it is affected.

What it is: CVE-2024-49980 is a medium-severity vulnerability in Linux kernel, published on 21 Oct 2024. 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-2024-49980 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-2024-49980/ (Markdown: https://insights.sbomify.com/CVE-2024-49980/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-49980
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-49980
- OSV: https://osv.dev/vulnerability/CVE-2024-49980

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-49980/
Summaries are generated and may contain mistakes; the official description above is the record.