{"api_version":"1","generated_at":"2026-09-21T18:31:57+00:00","cve":"CVE-2026-90100","urls":{"html":"https://cve.report/CVE-2026-90100","api":"https://cve.report/api/cve/CVE-2026-90100.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-90100","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-90100"},"summary":{"title":"ptp: netc: fix period truncation and potential divide-by-zero in PEROUT","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nptp: netc: fix period truncation and potential divide-by-zero in PEROUT\n\nThe max_period bound in net_timer_enable_perout() was computed as:\n\n  max_period = (u64)NETC_TMR_DEFAULT_FIPER + integral_period;\n\nwhich exceeds U32_MAX when integral_period > 0 (e.g. 0x100000002 for\nthe default 333333333 Hz clock). A period_ns that passes this check but\nexceeds U32_MAX is then silently truncated when stored into the u32\nstruct netc_pp::period field.\n\nA truncated value of zero can reach netc_timer_set_perout_alarm(), where\nthe local u32 period variable would also be 0, causing a divide-by-zero\nin roundup_u64(delta, period) whenever the stime < min_time branch is\ntaken (which always happens for a start time of {0, 0}).\n\nAdditionally, netc_timer_enable_periodic_pulse() and\nnetc_timer_enable_fiper() both compute:\n\n  fiper = pp->period - integral_period;\n\nA zero pp->period results in an unsigned wraparound to 0xFFFFFFFD,\nmis-programming the FIPER hardware register.\n\nFix all three issues by capping max_period at NETC_TMR_DEFAULT_FIPER\n(0xFFFFFFFF). This ensures that any period_ns passing the range check\nfits in a u32 without truncation, so the stored value is always valid\nand non-zero. The accepted range is reduced by integral_period ns\n(typically only a few nanoseconds), which is negligible in practice.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-17 17:17:01","updated_at":"2026-09-17 17:17:01"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/777dbc9914b2f003f1d44af80c7a4a395c5961b2","name":"https://git.kernel.org/stable/c/777dbc9914b2f003f1d44af80c7a4a395c5961b2","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/08988d1941e180f0ad30d91233cb64f3418ba23c","name":"https://git.kernel.org/stable/c/08988d1941e180f0ad30d91233cb64f3418ba23c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/51fe3fe0ffec033bd831c71d9bee3dee827e491c","name":"https://git.kernel.org/stable/c/51fe3fe0ffec033bd831c71d9bee3dee827e491c","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-90100","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90100","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 671e266835b8a87d6cc2c6db962de23783405dd8 51fe3fe0ffec033bd831c71d9bee3dee827e491c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 671e266835b8a87d6cc2c6db962de23783405dd8 08988d1941e180f0ad30d91233cb64f3418ba23c git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 671e266835b8a87d6cc2c6db962de23783405dd8 777dbc9914b2f003f1d44af80c7a4a395c5961b2 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.52 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.6 7.2.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.3-rc1 * 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/ptp/ptp_netc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"51fe3fe0ffec033bd831c71d9bee3dee827e491c","status":"affected","version":"671e266835b8a87d6cc2c6db962de23783405dd8","versionType":"git"},{"lessThan":"08988d1941e180f0ad30d91233cb64f3418ba23c","status":"affected","version":"671e266835b8a87d6cc2c6db962de23783405dd8","versionType":"git"},{"lessThan":"777dbc9914b2f003f1d44af80c7a4a395c5961b2","status":"affected","version":"671e266835b8a87d6cc2c6db962de23783405dd8","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/ptp/ptp_netc.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.18"},{"lessThan":"6.18","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.52","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.6","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.3-rc1","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.52","versionStartIncluding":"6.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.6","versionStartIncluding":"6.18","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"6.18","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nptp: netc: fix period truncation and potential divide-by-zero in PEROUT\n\nThe max_period bound in net_timer_enable_perout() was computed as:\n\n  max_period = (u64)NETC_TMR_DEFAULT_FIPER + integral_period;\n\nwhich exceeds U32_MAX when integral_period > 0 (e.g. 0x100000002 for\nthe default 333333333 Hz clock). A period_ns that passes this check but\nexceeds U32_MAX is then silently truncated when stored into the u32\nstruct netc_pp::period field.\n\nA truncated value of zero can reach netc_timer_set_perout_alarm(), where\nthe local u32 period variable would also be 0, causing a divide-by-zero\nin roundup_u64(delta, period) whenever the stime < min_time branch is\ntaken (which always happens for a start time of {0, 0}).\n\nAdditionally, netc_timer_enable_periodic_pulse() and\nnetc_timer_enable_fiper() both compute:\n\n  fiper = pp->period - integral_period;\n\nA zero pp->period results in an unsigned wraparound to 0xFFFFFFFD,\nmis-programming the FIPER hardware register.\n\nFix all three issues by capping max_period at NETC_TMR_DEFAULT_FIPER\n(0xFFFFFFFF). This ensures that any period_ns passing the range check\nfits in a u32 without truncation, so the stored value is always valid\nand non-zero. The accepted range is reduced by integral_period ns\n(typically only a few nanoseconds), which is negligible in practice."}],"providerMetadata":{"dateUpdated":"2026-09-17T16:06:11.515Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/51fe3fe0ffec033bd831c71d9bee3dee827e491c"},{"url":"https://git.kernel.org/stable/c/08988d1941e180f0ad30d91233cb64f3418ba23c"},{"url":"https://git.kernel.org/stable/c/777dbc9914b2f003f1d44af80c7a4a395c5961b2"}],"title":"ptp: netc: fix period truncation and potential divide-by-zero in PEROUT","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-90100","datePublished":"2026-09-17T16:06:11.515Z","dateReserved":"2026-09-11T19:38:34.786Z","dateUpdated":"2026-09-17T16:06:11.515Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-17 17:17:01","lastModifiedDate":"2026-09-17 17:17:01","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"90100","Ordinal":"1","Title":"ptp: netc: fix period truncation and potential divide-by-zero in","CVE":"CVE-2026-90100","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"90100","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nptp: netc: fix period truncation and potential divide-by-zero in PEROUT\n\nThe max_period bound in net_timer_enable_perout() was computed as:\n\n  max_period = (u64)NETC_TMR_DEFAULT_FIPER + integral_period;\n\nwhich exceeds U32_MAX when integral_period > 0 (e.g. 0x100000002 for\nthe default 333333333 Hz clock). A period_ns that passes this check but\nexceeds U32_MAX is then silently truncated when stored into the u32\nstruct netc_pp::period field.\n\nA truncated value of zero can reach netc_timer_set_perout_alarm(), where\nthe local u32 period variable would also be 0, causing a divide-by-zero\nin roundup_u64(delta, period) whenever the stime < min_time branch is\ntaken (which always happens for a start time of {0, 0}).\n\nAdditionally, netc_timer_enable_periodic_pulse() and\nnetc_timer_enable_fiper() both compute:\n\n  fiper = pp->period - integral_period;\n\nA zero pp->period results in an unsigned wraparound to 0xFFFFFFFD,\nmis-programming the FIPER hardware register.\n\nFix all three issues by capping max_period at NETC_TMR_DEFAULT_FIPER\n(0xFFFFFFFF). This ensures that any period_ns passing the range check\nfits in a u32 without truncation, so the stored value is always valid\nand non-zero. The accepted range is reduced by integral_period ns\n(typically only a few nanoseconds), which is negligible in practice.","Type":"Description","Title":"ptp: netc: fix period truncation and potential divide-by-zero in"}]}}}