{"api_version":"1","generated_at":"2026-09-11T22:32:24+00:00","cve":"CVE-2026-89436","urls":{"html":"https://cve.report/CVE-2026-89436","api":"https://cve.report/api/cve/CVE-2026-89436.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-89436","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-89436"},"summary":{"title":"platform/x86: panasonic-laptop: Fix sentinel write past pcc->sinf[]","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nplatform/x86: panasonic-laptop: Fix sentinel write past pcc->sinf[]\n\nacpi_pcc_retrieve_biosdata() rejects SINF packages only when\npcc->num_sifr is strictly less than hkey->package.count, then\nunconditionally writes a trailing sentinel at\npcc->sinf[hkey->package.count]. But pcc->sinf[] is allocated with\nexactly pcc->num_sifr elements (valid indices 0..num_sifr-1), so that\nwrite needs num_sifr strictly greater than package.count to stay in\nbounds -- num_sifr == package.count passes the existing check but\nstill overflows by one element.\n\nThis is exactly the case probe()'s existing num_sifr++ workaround\n(\"Some DSDT-s have an off-by-one bug where the SINF package count is\none higher than the SQTY reported value\") is written to accommodate:\nwhen a DSDT's SINF package count equals SQTY+1, the workaround makes\nnum_sifr equal to package.count, which is precisely the boundary that\noverflows here. Found via UBSan (array-index-out-of-bounds) on\nhardware where HKEY.SQTY returns 37 and HKEY.SINF()'s package has 38\nelements: num_sifr becomes 38 after the += 1 workaround, the loop\ncorrectly fills indices 0..37, and the sentinel write then targets\nindex 38, one past the end -- a silent 4-byte heap overflow on kernels\nwithout CONFIG_UBSAN.\n\nTightening the rejection check to num_sifr <= package.count would\navoid the overflow but breaks probe() entirely on exactly this\nhardware, since num_sifr == package.count is the case the off-by-one\nworkaround exists to support. Nothing else in the driver reads this\nsentinel value back, so simply skip the write when there is no room\nfor it instead.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-11 20:19:23","updated_at":"2026-09-11 20:19:23"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/a93df956ee4d903735b6d395362c839cb1dc07e3","name":"https://git.kernel.org/stable/c/a93df956ee4d903735b6d395362c839cb1dc07e3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/329f10d8be193bf36af124e00b9dd6644cd71724","name":"https://git.kernel.org/stable/c/329f10d8be193bf36af124e00b9dd6644cd71724","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-89436","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89436","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3d0dbd18ce908292607bb6cf37c978ece8a33d4 a93df956ee4d903735b6d395362c839cb1dc07e3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a3d0dbd18ce908292607bb6cf37c978ece8a33d4 329f10d8be193bf36af124e00b9dd6644cd71724 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.2","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2.4 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/platform/x86/panasonic-laptop.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"a93df956ee4d903735b6d395362c839cb1dc07e3","status":"affected","version":"a3d0dbd18ce908292607bb6cf37c978ece8a33d4","versionType":"git"},{"lessThan":"329f10d8be193bf36af124e00b9dd6644cd71724","status":"affected","version":"a3d0dbd18ce908292607bb6cf37c978ece8a33d4","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/platform/x86/panasonic-laptop.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"7.2"},{"lessThan":"7.2","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"7.2.*","status":"unaffected","version":"7.2.4","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":"7.2.4","versionStartIncluding":"7.2","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.3-rc1","versionStartIncluding":"7.2","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nplatform/x86: panasonic-laptop: Fix sentinel write past pcc->sinf[]\n\nacpi_pcc_retrieve_biosdata() rejects SINF packages only when\npcc->num_sifr is strictly less than hkey->package.count, then\nunconditionally writes a trailing sentinel at\npcc->sinf[hkey->package.count]. But pcc->sinf[] is allocated with\nexactly pcc->num_sifr elements (valid indices 0..num_sifr-1), so that\nwrite needs num_sifr strictly greater than package.count to stay in\nbounds -- num_sifr == package.count passes the existing check but\nstill overflows by one element.\n\nThis is exactly the case probe()'s existing num_sifr++ workaround\n(\"Some DSDT-s have an off-by-one bug where the SINF package count is\none higher than the SQTY reported value\") is written to accommodate:\nwhen a DSDT's SINF package count equals SQTY+1, the workaround makes\nnum_sifr equal to package.count, which is precisely the boundary that\noverflows here. Found via UBSan (array-index-out-of-bounds) on\nhardware where HKEY.SQTY returns 37 and HKEY.SINF()'s package has 38\nelements: num_sifr becomes 38 after the += 1 workaround, the loop\ncorrectly fills indices 0..37, and the sentinel write then targets\nindex 38, one past the end -- a silent 4-byte heap overflow on kernels\nwithout CONFIG_UBSAN.\n\nTightening the rejection check to num_sifr <= package.count would\navoid the overflow but breaks probe() entirely on exactly this\nhardware, since num_sifr == package.count is the case the off-by-one\nworkaround exists to support. Nothing else in the driver reads this\nsentinel value back, so simply skip the write when there is no room\nfor it instead."}],"providerMetadata":{"dateUpdated":"2026-09-11T19:43:06.732Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/a93df956ee4d903735b6d395362c839cb1dc07e3"},{"url":"https://git.kernel.org/stable/c/329f10d8be193bf36af124e00b9dd6644cd71724"}],"title":"platform/x86: panasonic-laptop: Fix sentinel write past pcc->sinf[]","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-89436","datePublished":"2026-09-11T19:43:06.732Z","dateReserved":"2026-09-11T19:38:34.702Z","dateUpdated":"2026-09-11T19:43:06.732Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-09-11 20:19:23","lastModifiedDate":"2026-09-11 20:19:23","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"89436","Ordinal":"1","Title":"platform/x86: panasonic-laptop: Fix sentinel write past pcc->sin","CVE":"CVE-2026-89436","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"89436","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nplatform/x86: panasonic-laptop: Fix sentinel write past pcc->sinf[]\n\nacpi_pcc_retrieve_biosdata() rejects SINF packages only when\npcc->num_sifr is strictly less than hkey->package.count, then\nunconditionally writes a trailing sentinel at\npcc->sinf[hkey->package.count]. But pcc->sinf[] is allocated with\nexactly pcc->num_sifr elements (valid indices 0..num_sifr-1), so that\nwrite needs num_sifr strictly greater than package.count to stay in\nbounds -- num_sifr == package.count passes the existing check but\nstill overflows by one element.\n\nThis is exactly the case probe()'s existing num_sifr++ workaround\n(\"Some DSDT-s have an off-by-one bug where the SINF package count is\none higher than the SQTY reported value\") is written to accommodate:\nwhen a DSDT's SINF package count equals SQTY+1, the workaround makes\nnum_sifr equal to package.count, which is precisely the boundary that\noverflows here. Found via UBSan (array-index-out-of-bounds) on\nhardware where HKEY.SQTY returns 37 and HKEY.SINF()'s package has 38\nelements: num_sifr becomes 38 after the += 1 workaround, the loop\ncorrectly fills indices 0..37, and the sentinel write then targets\nindex 38, one past the end -- a silent 4-byte heap overflow on kernels\nwithout CONFIG_UBSAN.\n\nTightening the rejection check to num_sifr <= package.count would\navoid the overflow but breaks probe() entirely on exactly this\nhardware, since num_sifr == package.count is the case the off-by-one\nworkaround exists to support. Nothing else in the driver reads this\nsentinel value back, so simply skip the write when there is no room\nfor it instead.","Type":"Description","Title":"platform/x86: panasonic-laptop: Fix sentinel write past pcc->sin"}]}}}