Live › vulnerability › CVE-2026-98616
Go to dashboardThe fbnic network driver in the Linux kernel keeps a count of napi vectors after freeing them during suspend or a failed resume, so a later close dereferences freed memory. The sources describe a kernel NULL pointer dereference in fbnic_dbg_down, which crashes the machine rather than granting an attacker access.
Summary written from the sources below. Check the originals before acting.
First seen by InfraStack 2026-10-23 21:57 UTC. All times on this page are UTC.
Only hosts that use a Meta fbnic network adapter with this driver loaded, and only when a PCIe error recovery or a resume open fails. Systems without fbnic hardware can skip it. The sources do not name a version range.
No product ranges from the sources yet.
uname -r and check whether the kernel includes the fbnic num_napi fix in its stable release noteslspci -k | grep -A3 -i fbnic to see if the fbnic driver is bound to a deviceEach row is the first time that source carried this signal. The analyst’s rows are its own findings.
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:
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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