{"id":"CVE-2026-99184","title":"accel/rocket: search every core slot when a core is removed","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\naccel/rocket: search every core slot when a core is removed\n\nrocket_remove() decrements rdev->num_cores for each core it removes,\nwhile find_core_for_dev() searches slo…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ed98261b41687323ffa02ca20fef1e60b38fd1aa < 5078c91f5c84bb383d0a10ed39856f98575e39cf","Linux >= ed98261b41687323ffa02ca20fef1e60b38fd1aa < 134451cf95cb6aa04b725fbfa04e878d072756f5","Linux >= ed98261b41687323ffa02ca20fef1e60b38fd1aa < 6eff1d69dae808a1518aee5a58d0853a8db3f1be","Linux 6.18"],"published":"2026-10-28","updated":"2026-10-28","sourceUpdated":"2026-10-28T10:35:42.469Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-99184","references":[{"url":"https://git.kernel.org/stable/c/5078c91f5c84bb383d0a10ed39856f98575e39cf"},{"url":"https://git.kernel.org/stable/c/134451cf95cb6aa04b725fbfa04e878d072756f5"},{"url":"https://git.kernel.org/stable/c/6eff1d69dae808a1518aee5a58d0853a8db3f1be"}],"tags":["cve.org"],"ingestedAt":"2026-10-28T11:09:40.378Z","slug":"CVE-2026-99184","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\naccel/rocket: search every core slot when a core is removed\n\nrocket_remove() decrements rdev->num_cores for each core it removes,\nwhile find_core_for_dev() searches slots 0 to num_cores - 1. Unbinding\nthe cores in the order they were bound therefore loses the last one: by\nthe time it is removed the search range has already shrunk past its\nslot, so find_core_for_dev() returns -1 and rocket_remove() gives up\nwithout doing anything.\n\nnum_cores never reaches zero, rocket_device_fini() never runs, and the\nfile-scoped rdev keeps pointing at a device that is going away. Binding\nthe cores again starts from that stale count, because rocket_probe()\ntakes rdev->num_cores as the slot to fill. On an RK3588, which describes\nthree cores, the second round lands on slots 1, 2 and 3 while rdev->cores\nwas allocated with room for three:\n\n  rocket fdab0000.npu: Rockchip NPU core 1 version: 1179210309\n  rocket fdac0000.npu: Rockchip NPU core 2 version: 1179210309\n  rocket fdad0000.npu: Rockchip NPU core 3 version: 1179210309\n\nThe write to rdev->cores[3] is past the end of the array.\n\nNothing in tree reads the core array often enough to notice, so the\noverrun is silent today. It turned up while testing a devfreq series on\ntop of this, where a worker walks every core a few times a second, and\nUBSAN caught the first bool it read out of the overrun entry:\n\n  UBSAN: invalid-load in drivers/accel/rocket/rocket_devfreq.c:47:10\n  load of value 5 is not a valid value for type '_Bool'\n  Workqueue: devfreq_wq devfreq_monitor\n\nRecord how many slots were allocated and search all of them. Every core\nis then found on removal, num_cores reaches zero, the device is torn down\nand a later bind starts from a clean rdev.\n\nThis does not make unbinding a single core out of several work. probe\nstill takes num_cores as the slot to fill, so rebinding one core while\nits siblings stay bound would write over a slot that is already in use,\nand rocket_open() still reaches for cores[0] whether or not anything is\nthere. Both of those want more thought than a fix should carry.\n\nFound by unbinding and rebinding all three cores on an Orange Pi 5 Plus.\nWith this applied, 25 unbind/rebind rounds and 5 module unload/reload\nrounds run clean there: the cores land in slots 0, 1 and 2 every time,\nwhichever order they are bound in, and the shared supply goes back to a\nsingle user after each round.\n\n## Affected\n\n- `Linux >= ed98261b41687323ffa02ca20fef1e60b38fd1aa < 5078c91f5c84bb383d0a10ed39856f98575e39cf`\n- `Linux >= ed98261b41687323ffa02ca20fef1e60b38fd1aa < 134451cf95cb6aa04b725fbfa04e878d072756f5`\n- `Linux >= ed98261b41687323ffa02ca20fef1e60b38fd1aa < 6eff1d69dae808a1518aee5a58d0853a8db3f1be`\n- `Linux 6.18`\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":[]}