# CVE-2026-45977: linux: In the Linux kernel, the following vulnerability has been resolved:  fbnic: close fw_log race between users and teard...

CVE-2026-45977 is fixed in linux on 1 platform by DEBIAN-CVE-2026-45977 (version 6.18.14-1), released May 27, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-45977
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0012
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 27, 2026

## Description

In the Linux kernel, the following vulnerability has been resolved:  fbnic: close fw_log race between users and teardown  Fixes a theoretical race on fw_log between the teardown path and fw_log write functions.  fw_log is written inside fbnic_fw_log_write() and can be reached from the mailbox handler fbnic_fw_msix_intr(), but fw_log is freed before IRQ/MBX teardown during cleanup, resulting in a potential data race of dereferencing a freed/null variable.  Possible Interleaving Scenario:   CPU0: fbnic_fw_msix_intr() // Entry           fbnic_fw_log_write()             if (fbnic_fw_log_ready())   // true             ... preempt ...   CPU1: fbnic_remove() // Entry           fbnic_fw_log_free()             vfree(log->data_start);             log->data_start = NULL;   CPU0: continues, walks log->entries or writes to log->data_start  The initialization also has an incorrect order problem, as the fw_log is currently allocated after MBX setup during initialization. Fix the problems by adjusting the synchronization order to put initialization in place before the mailbox is enabled, and not cleared until after the mailbox has been disabled.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 14 | 6.18.14-1 | [DEBIAN-CVE-2026-45977](https://patchblox.com/security/data/fix/linux/debian-cve-2026-45977.md) | May 27, 2026 |

---

Data as of 2026-11-08T06:59:42Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.