# CVE-2024-43817: net: missing check virtio

> Missing checks in the Linux kernel's virtio_net_hdr_to_skb function allow attackers to trigger kernel crashes via crafted network packets.

- **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:** 17 Aug 2024
- **Updated:** 23 May 2026
- **Also known as:** AZL-48489, BELL-CVE-2024-43817, DEBIAN-CVE-2024-43817, GHSA-6xh6-65h6-5hr6, ROOT-OS-DEBIAN-11-CVE-2024-43817, UBUNTU-CVE-2024-43817

## What is CVE-2024-43817?

CVE-2024-43817 is a medium-severity denial of service vulnerability in Linux kernel, published on 17 Aug 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:

net: missing check virtio

Two missing check in virtio_net_hdr_to_skb() allowed syzbot
to crash kernels again

1. After the skb_segment function the buffer may become non-linear
(nr_frags != 0), but since the SKBTX_SHARED_FRAG flag is not set anywhere
the __skb_linearize function will not be executed, then the buffer will
remain non-linear. Then the condition (offset >= skb_headlen(skb))
becomes true, which causes WARN_ON_ONCE in skb_checksum_help.

2. The struct sk_buff and struct virtio_net_hdr members must be
mathematically related.
(gso_size) must be greater than (needed) otherwise WARN_ON_ONCE.
(remainder) must be greater than (needed) otherwise WARN_ON_ONCE.
(remainder) may be 0 if division is without remainder.

offset+2 (4191) > skb_headlen() (1116)
WARNING: CPU: 1 PID: 5084 at net/core/dev.c:3303 skb_checksum_help+0x5e2/0x740 net/core/dev.c:3303
Modules linked in:
CPU: 1 PID: 5084 Comm: syz-executor336 Not tainted 6.7.0-rc3-syzkaller-00014-gdf60cee26a2e #0
Hardware name: Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
RIP: 0010:skb_checksum_help+0x5e2/0x740 net/core/dev.c:3303
Code: 89 e8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 52 01 00 00 44 89 e2 2b 53 74 4c 89 ee 48 c7 c7 40 57 e9 8b e8 af 8f dd f8 90 <0f> 0b 90 90 e9 87 fe ff ff e8 40 0f 6e f9 e9 4b fa ff ff 48 89 ef
RSP: 0018:ffffc90003a9f338 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff888025125780 RCX: ffffffff814db209
RDX: ffff888015393b80 RSI: ffffffff814db216 RDI: 0000000000000001
RBP: ffff8880251257f4 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000001 R12: 000000000000045c
R13: 000000000000105f R14: ffff8880251257f0 R15: 000000000000105d
FS:  0000555555c24380(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002000f000 CR3: 0000000023151000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 ip_do_fragment+0xa1b/0x18b0 net/ipv4/ip_output.c:777
 ip_fragment.constprop.0+0x161/0x230 net/ipv4/ip_output.c:584
 ip_finish_output_gso net/ipv4/ip_output.c:286 [inline]
 __ip_finish_output net/ipv4/ip_output.c:308 [inline]
 __ip_finish_output+0x49c/0x650 net/ipv4/ip_output.c:295
 ip_finish_output+0x31/0x310 net/ipv4/ip_output.c:323
 NF_HOOK_COND include/linux/netfilter.h:303 [inline]
 ip_output+0x13b/0x2a0 net/ipv4/ip_output.c:433
 dst_output include/net/dst.h:451 [inline]
 ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:129
 iptunnel_xmit+0x5b4/0x9b0 net/ipv4/ip_tunnel_core.c:82
 ipip6_tunnel_xmit net/ipv6/sit.c:1034 [inline]
 sit_tunnel_xmit+0xed2/0x28f0 net/ipv6/sit.c:1076
 __netdev_start_xmit include/linux/netdevice.h:4940 [inline]
 netdev_start_xmit include/linux/netdevice.h:4954 [inline]
 xmit_one net/core/dev.c:3545 [inline]
 dev_hard_start_xmit+0x13d/0x6d0 net/core/dev.c:3561
 __dev_queue_xmit+0x7c1/0x3d60 net/core/dev.c:4346
 dev_queue_xmit include/linux/netdevice.h:3134 [inline]
 packet_xmit+0x257/0x380 net/packet/af_packet.c:276
 packet_snd net/packet/af_packet.c:3087 [inline]
 packet_sendmsg+0x24ca/0x5240 net/packet/af_packet.c:3119
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg+0xd5/0x180 net/socket.c:745
 __sys_sendto+0x255/0x340 net/socket.c:2190
 __do_sys_sendto net/socket.c:2202 [inline]
 __se_sys_sendto net/socket.c:2198 [inline]
 __x64_sys_sendto+0xe0/0x1b0 net/socket.c:2198
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x40/0x110 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x63/0x6b

Found by Linux Verification Center (linuxtesting.org) with Syzkaller

## Which versions are affected by CVE-2024-43817?

It affects 1 product.


Products: Linux kernel.

## How do I fix CVE-2024-43817?

Apply the vendor's patch.

## Is CVE-2024-43817 being exploited?

There is no known exploitation of CVE-2024-43817 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-2024-43817 and fix it if it is affected.

What it is: CVE-2024-43817 is a medium-severity denial of service vulnerability in Linux kernel, published on 17 Aug 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-2024-43817 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-2024-43817/ (Markdown: https://insights.sbomify.com/CVE-2024-43817/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2024-43817
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2024-43817
- OSV: https://osv.dev/vulnerability/CVE-2024-43817

---
From sbomify Insights: https://insights.sbomify.com/CVE-2024-43817/
Summaries are generated and may contain mistakes; the official description above is the record.