{"id":"CVE-2026-89978","state":"PUBLISHED","title":"accel/amdxdna: return early from a zero-length flush","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.","publishedAt":"2026-09-16T10:32:55.928Z","updatedAt":"2026-10-19T08:55:52.997Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e252e3f3488a49267e08ea7d972ac5ba3f2f1763","status":"affected","lessThan":"45962da5821d0a691f638ccb13842889156d8969","versionType":"git"},{"version":"e252e3f3488a49267e08ea7d972ac5ba3f2f1763","status":"affected","lessThan":"f00def884a831dc49eb659dac2dd09dbfd21e67f","versionType":"git"},{"version":"e252e3f3488a49267e08ea7d972ac5ba3f2f1763","status":"affected","lessThan":"dc14753664240cedf669623b27ae9922b0618b25","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/accel/amdxdna/amdxdna_gem.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/accel/amdxdna/amdxdna_gem.c"]}],"references":["https://git.kernel.org/stable/c/45962da5821d0a691f638ccb13842889156d8969","https://git.kernel.org/stable/c/f00def884a831dc49eb659dac2dd09dbfd21e67f","https://git.kernel.org/stable/c/dc14753664240cedf669623b27ae9922b0618b25"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:26.108Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/89xxx/CVE-2026-89978.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89978","state":"PUBLISHED","datePublished":"2026-09-16T10:32:55.928Z","dateUpdated":"2026-10-19T08:55:52.997Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-11T19:38:34.779Z"},"containers":{"cna":{"title":"accel/amdxdna: return early from a zero-length flush","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e252e3f3488a49267e08ea7d972ac5ba3f2f1763","status":"affected","lessThan":"45962da5821d0a691f638ccb13842889156d8969","versionType":"git"},{"version":"e252e3f3488a49267e08ea7d972ac5ba3f2f1763","status":"affected","lessThan":"f00def884a831dc49eb659dac2dd09dbfd21e67f","versionType":"git"},{"version":"e252e3f3488a49267e08ea7d972ac5ba3f2f1763","status":"affected","lessThan":"dc14753664240cedf669623b27ae9922b0618b25","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/accel/amdxdna/amdxdna_gem.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.17","versionType":"semver"},{"version":"6.18.52","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.5","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/accel/amdxdna/amdxdna_gem.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/45962da5821d0a691f638ccb13842889156d8969"},{"url":"https://git.kernel.org/stable/c/f00def884a831dc49eb659dac2dd09dbfd21e67f"},{"url":"https://git.kernel.org/stable/c/dc14753664240cedf669623b27ae9922b0618b25"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-19T08:55:52.997Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"6.18.52"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.2.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}