{"api_version":"1","generated_at":"2026-08-25T21:07:01+00:00","cve":"CVE-2026-72141","urls":{"html":"https://cve.report/CVE-2026-72141","api":"https://cve.report/api/cve/CVE-2026-72141.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-72141","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-72141"},"summary":{"title":"i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)\n\nSMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the\ninterrupt-driven block-read state machine rejects it as -EPROTO. Worse,\nit returns without a NACK+STOP: the next receive cycle has already\nstarted, so the target keeps holding SDA and the bus stays stuck until a\npower cycle of this i2c controller.\n\nAccept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to\n2 so i2c_imx_isr_read_continue() emits STOP via its normal last-byte\npath. The dummy byte is discarded; block-read callers only consume\nbuf[0..count-1].\n\nReading I2DR has likewise already armed the next byte on the\ncount > I2C_SMBUS_BLOCK_MAX error path, so NACK it (TXAK) before aborting\nwith -EPROTO; otherwise the failing transfer's STOP cannot complete and\nthe bus stays held.\n\nThe atomic path regressed earlier (v3.16) and is fixed separately; this\npatch covers only the v6.13 state-machine rework.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 06:21:31","updated_at":"2026-08-17 06:18:14"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/56ddfc18ea8f7d77747658892873eb632b2ed530","name":"https://git.kernel.org/stable/c/56ddfc18ea8f7d77747658892873eb632b2ed530","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/07fd9385f0d87dff4b34f355f68adf701080cb24","name":"https://git.kernel.org/stable/c/07fd9385f0d87dff4b34f355f68adf701080cb24","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/5d3240f42a667e29262aff76fdebfcdac4980626","name":"https://git.kernel.org/stable/c/5d3240f42a667e29262aff76fdebfcdac4980626","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-72141","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-72141","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f5c2d4579ca6836f5604cca979debd68ecfe23f 5d3240f42a667e29262aff76fdebfcdac4980626 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f5c2d4579ca6836f5604cca979debd68ecfe23f 56ddfc18ea8f7d77747658892873eb632b2ed530 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5f5c2d4579ca6836f5604cca979debd68ecfe23f 07fd9385f0d87dff4b34f355f68adf701080cb24 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.13","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.13 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.40 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.5 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"72141","cve":"CVE-2026-72141","epss":"0.005830000","percentile":"0.450910000","score_date":"2026-08-17","updated_at":"2026-08-18 00:11:47"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["drivers/i2c/busses/i2c-imx.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"5d3240f42a667e29262aff76fdebfcdac4980626","status":"affected","version":"5f5c2d4579ca6836f5604cca979debd68ecfe23f","versionType":"git"},{"lessThan":"56ddfc18ea8f7d77747658892873eb632b2ed530","status":"affected","version":"5f5c2d4579ca6836f5604cca979debd68ecfe23f","versionType":"git"},{"lessThan":"07fd9385f0d87dff4b34f355f68adf701080cb24","status":"affected","version":"5f5c2d4579ca6836f5604cca979debd68ecfe23f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["drivers/i2c/busses/i2c-imx.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.13"},{"lessThan":"6.13","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.40","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.40","versionStartIncluding":"6.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.5","versionStartIncluding":"6.13","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"6.13","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)\n\nSMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the\ninterrupt-driven block-read state machine rejects it as -EPROTO. Worse,\nit returns without a NACK+STOP: the next receive cycle has already\nstarted, so the target keeps holding SDA and the bus stays stuck until a\npower cycle of this i2c controller.\n\nAccept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to\n2 so i2c_imx_isr_read_continue() emits STOP via its normal last-byte\npath. The dummy byte is discarded; block-read callers only consume\nbuf[0..count-1].\n\nReading I2DR has likewise already armed the next byte on the\ncount > I2C_SMBUS_BLOCK_MAX error path, so NACK it (TXAK) before aborting\nwith -EPROTO; otherwise the failing transfer's STOP cannot complete and\nthe bus stays held.\n\nThe atomic path regressed earlier (v3.16) and is fixed separately; this\npatch covers only the v6.13 state-machine rework."}],"metrics":[{"cvssV3_1":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - On NXP Layerscape/i.MX appliances, remotely reachable IPMI-over-LAN or management-plane requests invoke ipmi_ssif/pmbus i2c_smbus_read_block_data() on imx-i2c; a malicious or compromised bus peripheral returning SMBus block-read count 0 reaches the vulnerable IRQ handler without local login.\nAC:L - Once an SMBus block-read transaction is initiated and the target returns count byte 0 (a valid SMBus 3.1 response), the IRQ path deterministically omits NACK/STOP and locks the bus; the attacker controls both transaction initiation and slave response via compromised BMC/PMBus device or planted peripheral.\nPR:N - No Linux credentials are required when a malicious or compromised I2C slave returns count 0 during kernel-initiated SMBus block reads from IPMI SSIF, PMBus hwmon polling, or other automated drivers; OS privilege is not needed beyond influencing the bus response.\nUI:N - Exploitation requires no victim interaction because kernel subsystems (IPMI SSIF, PMBus hwmon, sensor drivers) automatically perform SMBus block reads during normal remote-management or background monitoring operations once the bus device responds.\nS:U - Impact is confined to locking the imx-i2c controller and attached I2C bus within the same kernel/host security boundary; it does not cross VM, container, or IOMMU isolation boundaries.\nC:N - The flaw is a missing NACK/STOP during SMBus block-read length handling; it causes a stuck I2C bus but does not corrupt kernel memory, leak data, or provide read primitives.\nI:N - No kernel or user data is modified; the bug only leaves the I2C controller in a hung bus state without write primitives, code execution, or integrity violations beyond loss of bus function.\nA:H - A successful trigger permanently locks the imx-i2c bus until controller power-cycle, denying all further I2C/SMBus communication to PMICs, sensors, EEPROMs, and BMC SSIF on safety-critical embedded, automotive, and datacenter systems."}]}],"providerMetadata":{"dateUpdated":"2026-08-17T05:40:49.962Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/5d3240f42a667e29262aff76fdebfcdac4980626"},{"url":"https://git.kernel.org/stable/c/56ddfc18ea8f7d77747658892873eb632b2ed530"},{"url":"https://git.kernel.org/stable/c/07fd9385f0d87dff4b34f355f68adf701080cb24"}],"title":"i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-72141","datePublished":"2026-08-15T05:53:14.754Z","dateReserved":"2026-08-09T03:40:39.908Z","dateUpdated":"2026-08-17T05:40:49.962Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 06:21:31","lastModifiedDate":"2026-08-17 06:18:14","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"72141","Ordinal":"1","Title":"i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)","CVE":"CVE-2026-72141","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"72141","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\ni2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)\n\nSMBus 3.1 6.5.7 allows a Block Read byte count of 0, but the\ninterrupt-driven block-read state machine rejects it as -EPROTO. Worse,\nit returns without a NACK+STOP: the next receive cycle has already\nstarted, so the target keeps holding SDA and the bus stays stuck until a\npower cycle of this i2c controller.\n\nAccept count=0: NACK the in-flight dummy byte (TXAK) and set msg->len to\n2 so i2c_imx_isr_read_continue() emits STOP via its normal last-byte\npath. The dummy byte is discarded; block-read callers only consume\nbuf[0..count-1].\n\nReading I2DR has likewise already armed the next byte on the\ncount > I2C_SMBUS_BLOCK_MAX error path, so NACK it (TXAK) before aborting\nwith -EPROTO; otherwise the failing transfer's STOP cannot complete and\nthe bus stays held.\n\nThe atomic path regressed earlier (v3.16) and is fixed separately; this\npatch covers only the v6.13 state-machine rework.","Type":"Description","Title":"i2c: imx: fix locked bus on SMBus block-read of 0 (IRQ)"}]}}}