{"id":"CVE-2026-98616","title":"eth: fbnic: reset num_napi when the napi vectors are freed","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\neth: fbnic: reset num_napi when the napi vectors are freed\n\nfbn->num_napi is the count of live napi vectors, each of which owns an\nIRQ.  The PM path had freed them with…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= bc6107771bb4be3009168cfda24d22131c026fe8 < c5b5aee41b9f5ed0743344be1c7b544555fa3cb9","Linux >= bc6107771bb4be3009168cfda24d22131c026fe8 < 4f4b767ffea7653a00904383908536e754f8ef5b","Linux >= bc6107771bb4be3009168cfda24d22131c026fe8 < 4bcc4a92c603fe7f062cea22e20da2e0ad6b12c3","Linux 6.11"],"published":"2026-10-18","updated":"2026-10-18","sourceUpdated":"2026-10-18T15:19:36.165Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98616","references":[{"url":"https://git.kernel.org/stable/c/c5b5aee41b9f5ed0743344be1c7b544555fa3cb9"},{"url":"https://git.kernel.org/stable/c/4f4b767ffea7653a00904383908536e754f8ef5b"},{"url":"https://git.kernel.org/stable/c/4bcc4a92c603fe7f062cea22e20da2e0ad6b12c3"}],"tags":["cve.org"],"ingestedAt":"2026-10-18T15:45:12.239Z","slug":"CVE-2026-98616","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\neth: fbnic: reset num_napi when the napi vectors are freed\n\nfbn->num_napi is the count of live napi vectors, each of which owns an\nIRQ.  The PM path had freed them without clearing the count.\nfbnic_pm_suspend() tears the datapath down via ndo_stop() and frees the\nIRQs, but leaves netif_running() true so resume knows to re-open.  Resume\nrebuilds the datapath in __fbnic_pm_resume() and fbnic_reset_queues() sets\nnum_napi and __fbnic_open() re-allocates the vectors.\n\nWhen the datapath is torn down but never rebuilt, num_napi is left\npointing at freed vectors under 2 different scenarios:\n - a PCIe error recovery that fails (fbnic_err_slot_reset() ->\n   __fbnic_pm_resume() returns an error -> PCI_ERS_RESULT_DISCONNECT), so\n   .resume never runs; or\n - an __fbnic_open() that fails partway on resume and unwinds, freeing\n   the vectors after fbnic_reset_queues() has already set num_napi.\n\nThe netdev is then running with num_napi > 0 but napi[] freed, and the\neventual remove/unbind close re-enters fbnic_down() -> fbnic_dbg_down()\nand dereferences the freed vectors:\n  BUG: kernel NULL pointer dereference, address: 0000000000000210\n  RIP: fbnic_dbg_down+0x28\n\nClear num_napi when the vectors are freed: in the suspend teardown (a\ngood resume re-establishes it before __fbnic_open()) and on the resume\nopen failure.  A redundant ndo_stop() then walks an empty napi[].  The\nnormal ndo_stop() down/up cycle is untouched and keeps num_napi for the\nnext ndo_open().\n\n## Affected\n\n- `Linux >= bc6107771bb4be3009168cfda24d22131c026fe8 < c5b5aee41b9f5ed0743344be1c7b544555fa3cb9`\n- `Linux >= bc6107771bb4be3009168cfda24d22131c026fe8 < 4f4b767ffea7653a00904383908536e754f8ef5b`\n- `Linux >= bc6107771bb4be3009168cfda24d22131c026fe8 < 4bcc4a92c603fe7f062cea22e20da2e0ad6b12c3`\n- `Linux 6.11`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}