CVE-2026-45977

fbnic: close fw_log race between users and teardown

MEDIUM
5.5
CVSS Score
Published: May 27, 2026 at 12:18 PM UTC
Updated: June 17, 2026 at 10:52 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.17 ≤ v < 6.18.146.17 ≤ v < 6.19.46.17 ≤ v < 7.06.19 ≤ v < 6.19.46.17ecc53b1b46c892d2e3cf3cf4393b6d219dc4ae3f
Vendor states this is fixed in 223cfef4812bdfa5ac5c1aa761cdba03cfe2c9cd (fixed)
Vendor states this is fixed in 5f10ab3643c58a22fbaee92c4701b00fcb4a465d (fixed)
Vendor states this is fixed in ee5492fd88cfc079c19fbeac78e9e53b7f6c04f3 (fixed)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.18.14 (unaffected)
Vendor states this is fixed in 6.19.4 (unaffected)
Vendor states this is fixed in 7.0 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
NVD-CWE-noinfo

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