{"api_version":"1","generated_at":"2026-10-24T16:08:28+00:00","cve":"CVE-2026-98919","urls":{"html":"https://cve.report/CVE-2026-98919","api":"https://cve.report/api/cve/CVE-2026-98919.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98919","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98919"},"summary":{"title":"drm/xe: harden adjust_idledly() against divide-by-zero and overflow","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe: harden adjust_idledly() against divide-by-zero and overflow\n\nadjust_idledly() has several corner-case issues flagged during review:\n\n  1. If xe_gt_clock_init() failed to recognise the crystal clock,\n     gt->info.timestamp_base is 0, which makes idledly_units_ps also 0.\n     The subsequent DIV_ROUND_CLOSEST(..., idledly_units_ps) is then a\n     divide-by-zero and panics the kernel.\n\n  2. The tick-to-ns conversions are done in u32:\n        idledly * idledly_units_ps, (maxcnt - 1) * 1000\n     Both overflow u32 before DIV_ROUND_CLOSEST() sees them.\n\n  3. If IDLE_WAIT_TIME reads back as 0, maxcnt evaluates to 0 and\n     the maxcnt - 1 clamp wraps to 0xFFFFFFFF in u32.\n\n  4. The register only stores whole ticks, so the clamped ns value has\n     to be converted to ticks and back. DIV_ROUND_CLOSEST() can round\n     that conversion up past maxcnt:\n\n       maxcnt = 640 ns, one tick = 666664 ps\n\n       clamp:        maxcnt - 1        = 639 ns\n       ns -> ticks:  639000 / 666664   = 0.958 -> rounds to 1 tick\n       tick -> ns:    1 * 666664 / 1000 = 667 ns\n\n     667 ns is programmed into RING_IDLEDLY, but 667 >= maxcnt (640),\n     so xe_gt_WARN_ON() fires again on every subsequent init.\n\nReturn early if timestamp_base is 0 (the unknown-crystal path).\nDo the conversions in u64 via the *_ULL() helpers so they cannot wrap.\nClamp with a floor (DIV_ROUND_DOWN_ULL) so the programmed delay stays\nstrictly below maxcnt, and guard the maxcnt == 0 case with a zero delay\nwhile still writing RING_IDLEDLY so INHIBIT_SWITCH_UNTIL_PREEMPTED is\ncleared.\n\nv2: Drop the redundant warn on the timestamp_base == 0 path;\n    xe_gt_clock_init() already warns on an unrecognised crystal clock.\n    Keep the early return to avoid the divide-by-zero. - Vinay\n\nv3: Field-mask the RING_IDLEDLY write with REG_FIELD_PREP(IDLE_DELAY, ...)\n    instead of writing the raw tick count, which could clobber\n    INHIBIT_SWITCH_UNTIL_PREEMPTED and reserved bits. Split the\n    inhibit-switch clear from the maxcnt clamp so a set inhibit bit no\n    longer forces a needless delay overwrite when the delay itself is\n    already valid. Use gt_to_xe(gt) instead of gt_to_xe(hwe->gt).\n\n(cherry picked from commit d864065ea25e9d12897c175de9176ce46677e176)","state":"PUBLISHED","assigner":"Linux","published_at":"2026-10-23 13:17:12","updated_at":"2026-10-23 13:17:12"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/531d4cd03118224022dc21ae25af052ce2a9e267","name":"https://git.kernel.org/stable/c/531d4cd03118224022dc21ae25af052ce2a9e267","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/90f467577ebc28c5bc4ba2f0f1b83a4419fb0740","name":"https://git.kernel.org/stable/c/90f467577ebc28c5bc4ba2f0f1b83a4419fb0740","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/2bcbfc5e7bfa9cc76818c54db698da5bdc13d9ff","name":"https://git.kernel.org/stable/c/2bcbfc5e7bfa9cc76818c54db698da5bdc13d9ff","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98919","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98919","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d2de4410a88ffc6053300d03041cc73b8c85dbaf 2bcbfc5e7bfa9cc76818c54db698da5bdc13d9ff git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d2de4410a88ffc6053300d03041cc73b8c85dbaf 531d4cd03118224022dc21ae25af052ce2a9e267 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected d2de4410a88ffc6053300d03041cc73b8c85dbaf 90f467577ebc28c5bc4ba2f0f1b83a4419fb0740 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.15","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.15 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.55 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.9 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/gpu/drm/xe/xe_hw_engine.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"2bcbfc5e7bfa9cc76818c54db698da5bdc13d9ff","status":"affected","version":"d2de4410a88ffc6053300d03041cc73b8c85dbaf","versionType":"git"},{"lessThan":"531d4cd03118224022dc21ae25af052ce2a9e267","status":"affected","version":"d2de4410a88ffc6053300d03041cc73b8c85dbaf","versionType":"git"},{"lessThan":"90f467577ebc28c5bc4ba2f0f1b83a4419fb0740","status":"affected","version":"d2de4410a88ffc6053300d03041cc73b8c85dbaf","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/gpu/drm/xe/xe_hw_engine.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.15"},{"lessThan":"6.15","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.55","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.9","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.55","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.9","versionStartIncluding":"6.15","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3","versionStartIncluding":"6.15","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe: harden adjust_idledly() against divide-by-zero and overflow\n\nadjust_idledly() has several corner-case issues flagged during review:\n\n  1. If xe_gt_clock_init() failed to recognise the crystal clock,\n     gt->info.timestamp_base is 0, which makes idledly_units_ps also 0.\n     The subsequent DIV_ROUND_CLOSEST(..., idledly_units_ps) is then a\n     divide-by-zero and panics the kernel.\n\n  2. The tick-to-ns conversions are done in u32:\n        idledly * idledly_units_ps, (maxcnt - 1) * 1000\n     Both overflow u32 before DIV_ROUND_CLOSEST() sees them.\n\n  3. If IDLE_WAIT_TIME reads back as 0, maxcnt evaluates to 0 and\n     the maxcnt - 1 clamp wraps to 0xFFFFFFFF in u32.\n\n  4. The register only stores whole ticks, so the clamped ns value has\n     to be converted to ticks and back. DIV_ROUND_CLOSEST() can round\n     that conversion up past maxcnt:\n\n       maxcnt = 640 ns, one tick = 666664 ps\n\n       clamp:        maxcnt - 1        = 639 ns\n       ns -> ticks:  639000 / 666664   = 0.958 -> rounds to 1 tick\n       tick -> ns:    1 * 666664 / 1000 = 667 ns\n\n     667 ns is programmed into RING_IDLEDLY, but 667 >= maxcnt (640),\n     so xe_gt_WARN_ON() fires again on every subsequent init.\n\nReturn early if timestamp_base is 0 (the unknown-crystal path).\nDo the conversions in u64 via the *_ULL() helpers so they cannot wrap.\nClamp with a floor (DIV_ROUND_DOWN_ULL) so the programmed delay stays\nstrictly below maxcnt, and guard the maxcnt == 0 case with a zero delay\nwhile still writing RING_IDLEDLY so INHIBIT_SWITCH_UNTIL_PREEMPTED is\ncleared.\n\nv2: Drop the redundant warn on the timestamp_base == 0 path;\n    xe_gt_clock_init() already warns on an unrecognised crystal clock.\n    Keep the early return to avoid the divide-by-zero. - Vinay\n\nv3: Field-mask the RING_IDLEDLY write with REG_FIELD_PREP(IDLE_DELAY, ...)\n    instead of writing the raw tick count, which could clobber\n    INHIBIT_SWITCH_UNTIL_PREEMPTED and reserved bits. Split the\n    inhibit-switch clear from the maxcnt clamp so a set inhibit bit no\n    longer forces a needless delay overwrite when the delay itself is\n    already valid. Use gt_to_xe(gt) instead of gt_to_xe(hwe->gt).\n\n(cherry picked from commit d864065ea25e9d12897c175de9176ce46677e176)"}],"providerMetadata":{"dateUpdated":"2026-10-23T12:05:08.723Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/2bcbfc5e7bfa9cc76818c54db698da5bdc13d9ff"},{"url":"https://git.kernel.org/stable/c/531d4cd03118224022dc21ae25af052ce2a9e267"},{"url":"https://git.kernel.org/stable/c/90f467577ebc28c5bc4ba2f0f1b83a4419fb0740"}],"title":"drm/xe: harden adjust_idledly() against divide-by-zero and overflow","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98919","datePublished":"2026-10-23T12:01:55.092Z","dateReserved":"2026-09-25T10:25:14.380Z","dateUpdated":"2026-10-23T12:05:08.723Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-23 13:17:12","lastModifiedDate":"2026-10-23 13:17:12","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98919","Ordinal":"1","Title":"drm/xe: harden adjust_idledly() against divide-by-zero and overf","CVE":"CVE-2026-98919","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98919","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/xe: harden adjust_idledly() against divide-by-zero and overflow\n\nadjust_idledly() has several corner-case issues flagged during review:\n\n  1. If xe_gt_clock_init() failed to recognise the crystal clock,\n     gt->info.timestamp_base is 0, which makes idledly_units_ps also 0.\n     The subsequent DIV_ROUND_CLOSEST(..., idledly_units_ps) is then a\n     divide-by-zero and panics the kernel.\n\n  2. The tick-to-ns conversions are done in u32:\n        idledly * idledly_units_ps, (maxcnt - 1) * 1000\n     Both overflow u32 before DIV_ROUND_CLOSEST() sees them.\n\n  3. If IDLE_WAIT_TIME reads back as 0, maxcnt evaluates to 0 and\n     the maxcnt - 1 clamp wraps to 0xFFFFFFFF in u32.\n\n  4. The register only stores whole ticks, so the clamped ns value has\n     to be converted to ticks and back. DIV_ROUND_CLOSEST() can round\n     that conversion up past maxcnt:\n\n       maxcnt = 640 ns, one tick = 666664 ps\n\n       clamp:        maxcnt - 1        = 639 ns\n       ns -> ticks:  639000 / 666664   = 0.958 -> rounds to 1 tick\n       tick -> ns:    1 * 666664 / 1000 = 667 ns\n\n     667 ns is programmed into RING_IDLEDLY, but 667 >= maxcnt (640),\n     so xe_gt_WARN_ON() fires again on every subsequent init.\n\nReturn early if timestamp_base is 0 (the unknown-crystal path).\nDo the conversions in u64 via the *_ULL() helpers so they cannot wrap.\nClamp with a floor (DIV_ROUND_DOWN_ULL) so the programmed delay stays\nstrictly below maxcnt, and guard the maxcnt == 0 case with a zero delay\nwhile still writing RING_IDLEDLY so INHIBIT_SWITCH_UNTIL_PREEMPTED is\ncleared.\n\nv2: Drop the redundant warn on the timestamp_base == 0 path;\n    xe_gt_clock_init() already warns on an unrecognised crystal clock.\n    Keep the early return to avoid the divide-by-zero. - Vinay\n\nv3: Field-mask the RING_IDLEDLY write with REG_FIELD_PREP(IDLE_DELAY, ...)\n    instead of writing the raw tick count, which could clobber\n    INHIBIT_SWITCH_UNTIL_PREEMPTED and reserved bits. Split the\n    inhibit-switch clear from the maxcnt clamp so a set inhibit bit no\n    longer forces a needless delay overwrite when the delay itself is\n    already valid. Use gt_to_xe(gt) instead of gt_to_xe(hwe->gt).\n\n(cherry picked from commit d864065ea25e9d12897c175de9176ce46677e176)","Type":"Description","Title":"drm/xe: harden adjust_idledly() against divide-by-zero and overf"}]}}}