CVE-2026-98615
eth: fbnic: Set AW_FLUSH_MODE alongside AW_FLUSH when flushing the mailbox
Published Oct 18, 2026
CVSS 3.1 · 4.4 Medium
EPSS < 1%
KEV · Not listed
Description
In the Linux kernel, the following vulnerability has been resolved:
eth: fbnic: Set AW_FLUSH_MODE alongside AW_FLUSH when flushing the mailbox
When tearing down the FW mailbox Rx ring, fbnic_mbx_reset_desc_ring()
writes AW_CFG with FLUSH set and everything else, BME included, cleared.
Clearing BME halts the device's writes to the host but leaves the staged
requests parked in the PUL write pipeline rather than draining them, so
on the write path FLUSH alone never terminates the outstanding requests
and the flush the firmware waits on never completes.
Add the FLUSH_MODE definition and set both bits so the staged writes
drain out of the pipeline on their own. BME stays cleared, so nothing
lands on the host; it is restored later in fbnic_mbx_init_desc_ring()
when the ring is rebuilt, once the outstanding writes are gone.
The read path is unaffected. AR_CFG has no equivalent mode bit and
AR_FLUSH terminates the outstanding reads by itself, so it is left as
is.
Both writes remain plain stores rather than read-modify-writes. That is
deliberate: the matching write in fbnic_mbx_init_desc_ring() restores
BME and the TLP attributes, and clears both flush bits as a side effect.
eth: fbnic: Set AW_FLUSH_MODE alongside AW_FLUSH when flushing the mailbox
When tearing down the FW mailbox Rx ring, fbnic_mbx_reset_desc_ring()
writes AW_CFG with FLUSH set and everything else, BME included, cleared.
Clearing BME halts the device's writes to the host but leaves the staged
requests parked in the PUL write pipeline rather than draining them, so
on the write path FLUSH alone never terminates the outstanding requests
and the flush the firmware waits on never completes.
Add the FLUSH_MODE definition and set both bits so the staged writes
drain out of the pipeline on their own. BME stays cleared, so nothing
lands on the host; it is restored later in fbnic_mbx_init_desc_ring()
when the ring is rebuilt, once the outstanding writes are gone.
The read path is unaffected. AR_CFG has no equivalent mode bit and
AR_FLUSH terminates the outstanding reads by itself, so it is left as
is.
Both writes remain plain stores rather than read-modify-writes. That is
deliberate: the matching write in fbnic_mbx_init_desc_ring() restores
BME and the TLP attributes, and clears both flush bits as a side effect.
Affected Products
-
CVE record
-
NVD configurations
No data
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Red Hat packages
No data
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OpenCVE enrichment
Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).
| Vendor | Product | Default status | Versions | ||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux | unaffected |
|
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| Linux | Linux | affected |
|
No data.
No data.
| Vendor | Product | Versions | ||||||||||||||||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Linux | Linux Kernel |
|
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| Linux | Linux Kernel |
|
Remediation
Tracking
Advisories
| Source | ID | Title |
|---|---|---|
 Debian DLA |
DLA-4850-1 | linux-6.12 security update |
 Ubuntu USN |
USN-9019-1 | Linux kernel (Azure) vulnerabilities |
| Ubuntu USN |
USN-9020-1 | Linux kernel vulnerabilities |
Metrics
No CVSS v4.0
Attack Vector Local
Attack Complexity Low
Privileges Required High
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
User Interaction None
No CVSS v3.0
No CVSS v2
This CVE is not in the KEV list.
Exploit prediction score: < 1% (0.168% probability within 30 days)
Key SSVC decision points have not yet been added.
References
History
Oct 23, 2026 12:45 AM
Weaknesses updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-362 CWE-409 |
Oct 21, 2026 12:30 PM
Weaknesses updated. Added references. Scoring metrics updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-459 | |
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Oct 18, 2026 11:00 PM
Weaknesses updated
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-362 CWE-409 |
Oct 18, 2026 3:30 PM
Description updated. Title updated. First appearance in the feed. Affected versions updated. Affected vendors updated. Added references
View changes
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: Set AW_FLUSH_MODE alongside AW_FLUSH when flushing the mailbox When tearing down the FW mailbox Rx ring, fbnic_mbx_reset_desc_ring() writes AW_CFG with FLUSH set and everything else, BME included, cleared. Clearing BME halts the device's writes to the host but leaves the staged requests parked in the PUL write pipeline rather than draining them, so on the write path FLUSH alone never terminates the outstanding requests and the flush the firmware waits on never completes. Add the FLUSH_MODE definition and set both bits so the staged writes drain out of the pipeline on their own. BME stays cleared, so nothing lands on the host; it is restored later in fbnic_mbx_init_desc_ring() when the ring is rebuilt, once the outstanding writes are gone. The read path is unaffected. AR_CFG has no equivalent mode bit and AR_FLUSH terminates the outstanding reads by itself, so it is left as is. Both writes remain plain stores rather than read-modify-writes. That is deliberate: the matching write in fbnic_mbx_init_desc_ring() restores BME and the TLP attributes, and clears both flush bits as a side effect. | |
| Title | eth: fbnic: Set AW_FLUSH_MODE alongside AW_FLUSH when flushing the mailbox | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Subscriptions
Weaknesses
