CVE-2026-45977

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.

Package Linux Kernel
Published 2026-05-27
Last modified 2026-05-27
Patch available
Yes

Affected versions

Linux kernel versions 6.17 and later are affected. Fixed in 6.18.14, 6.19.4, 7.0 and their respective stable series.

Affected from
≥ 6.17
Fixed in
✓ 6.18.14 6.18.x ✓ 6.19.4 6.19.x ✓ 7.0

References

The following references provide additional information about CVE-2026-45977 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.

Frequently asked questions

  • What is CVE-2026-45977?

    CVE-2026-45977 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 6.17 onward and has been patched in 6.18.14, 6.19.4 and 7.0. CVE-2026-45977 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.

  • Is there a patch available for CVE-2026-45977?

    Yes — CVE-2026-45977 has been patched. Fixed versions include 6.18.14, 6.19.4 and 7.0. If you are running Linux kernel 6.17 or later up to the fix versions, apply the relevant patch for your kernel branch.

  • Is CVE-2026-45977 actively exploited?

    No — CVE-2026-45977 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.