In the Linux kernel, the following vulnerability has been resolved:

eth: fbnic: reset num_napi when the napi vectors are freed

fbn->num_napi is the count of live napi vectors, each of which owns an
IRQ. The PM path had freed them without clearing the count.
fbnic_pm_suspend() tears the datapath down via ndo_stop() and frees the
IRQs, but leaves netif_running() true so resume knows to re-open. Resume
rebuilds the datapath in __fbnic_pm_resume() and fbnic_reset_queues() sets
num_napi and __fbnic_open() re-allocates the vectors.

When the datapath is torn down but never rebuilt, num_napi is left
pointing at freed vectors under 2 different scenarios:
- a PCIe error recovery that fails (fbnic_err_slot_reset() ->
__fbnic_pm_resume() returns an error -> PCI_ERS_RESULT_DISCONNECT), so
.resume never runs; or
- an __fbnic_open() that fails partway on resume and unwinds, freeing
the vectors after fbnic_reset_queues() has already set num_napi.

The netdev is then running with num_napi > 0 but napi[] freed, and the
eventual remove/unbind close re-enters fbnic_down() -> fbnic_dbg_down()
and dereferences the freed vectors:
BUG: kernel NULL pointer dereference, address: 0000000000000210
RIP: fbnic_dbg_down+0x28

Clear num_napi when the vectors are freed: in the suspend teardown (a
good resume re-establishes it before __fbnic_open()) and on the resume
open failure. A redundant ndo_stop() then walks an empty napi[]. The
normal ndo_stop() down/up cycle is untouched and keeps num_napi for the
next ndo_open().
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History

Sun, 18 Oct 2026 15:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: eth: fbnic: reset num_napi when the napi vectors are freed fbn->num_napi is the count of live napi vectors, each of which owns an IRQ. The PM path had freed them without clearing the count. fbnic_pm_suspend() tears the datapath down via ndo_stop() and frees the IRQs, but leaves netif_running() true so resume knows to re-open. Resume rebuilds the datapath in __fbnic_pm_resume() and fbnic_reset_queues() sets num_napi and __fbnic_open() re-allocates the vectors. When the datapath is torn down but never rebuilt, num_napi is left pointing at freed vectors under 2 different scenarios: - a PCIe error recovery that fails (fbnic_err_slot_reset() -> __fbnic_pm_resume() returns an error -> PCI_ERS_RESULT_DISCONNECT), so .resume never runs; or - an __fbnic_open() that fails partway on resume and unwinds, freeing the vectors after fbnic_reset_queues() has already set num_napi. The netdev is then running with num_napi > 0 but napi[] freed, and the eventual remove/unbind close re-enters fbnic_down() -> fbnic_dbg_down() and dereferences the freed vectors: BUG: kernel NULL pointer dereference, address: 0000000000000210 RIP: fbnic_dbg_down+0x28 Clear num_napi when the vectors are freed: in the suspend teardown (a good resume re-establishes it before __fbnic_open()) and on the resume open failure. A redundant ndo_stop() then walks an empty napi[]. The normal ndo_stop() down/up cycle is untouched and keeps num_napi for the next ndo_open().
Title eth: fbnic: reset num_napi when the napi vectors are freed
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-10-18T15:19:36.165Z

Reserved: 2026-09-25T10:25:14.360Z

Link: CVE-2026-98616

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-10-18T16:17:14.497

Modified: 2026-10-18T16:17:14.497

Link: CVE-2026-98616

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses

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