{"cve":"CVE-2026-89978","nvd":{"published":"2026-09-16T11:17:08.667","modified":"2026-10-19T09:18:44.607","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\naccel/amdxdna: return early from a zero-length flush\n\nSYNC_BO does not constrain its size, so a request for zero bytes reaches\ndrm_clflush_virt_range(), which ends with an unconditional\nclflushopt(end - 1). For an empty range that is the byte before the\nmapping, and abo->mem.kva comes from vmap(), so the access lands in the\nguard page below the vmalloc area and faults:\n\n  BUG: unable to handle page fault for address: ffffd16fbbc70fff\n  #PF: supervisor read access in kernel mode\n  Oops: Oops: 0000 [#1] SMP NOPTI\n  CPU: 7 UID: 1000 Comm: sync_bo_probe\n  RIP: 0010:drm_clflush_virt_range+0x3c/0x70\n  Call Trace:\n   amdxdna_drm_sync_bo_ioctl+0x124/0x430 [amdxdna]\n   drm_ioctl+0x301/0x4c0\n   __x64_sys_ioctl+0x115/0x2f0\n   do_syscall_64+0xa6/0x3d0\n\nAny process that can open the render node can do this. Reproduced 3 of 3\ntimes on a Strix Point NPU (1022:17f0), by calling SYNC_BO with size 0 on\nan AMDXDNA_BO_SHARE object. The import arm takes the same request but\nflushes the whole scatterlist, so it survives it.\n\nNothing needs flushing for an empty range, so answer before choosing a\npath.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/45962da5821d0a691f638ccb13842889156d8969","https://git.kernel.org/stable/c/dc14753664240cedf669623b27ae9922b0618b25","https://git.kernel.org/stable/c/f00def884a831dc49eb659dac2dd09dbfd21e67f"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:54:41.405518556+00:00"},"epss":{"cve":"CVE-2026-89978","score":0.00206,"percentile":0.10617,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}