{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64502", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.793Z", "datePublished": "2026-07-25T08:51:57.477Z", "dateUpdated": "2026-08-17T04:56:52.172Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T04:56:52.172Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices\n\nad_sigma_delta_clear_pending_event() falls through to the status register\nread path for devices with has_registers = false and no rdy_gpiod. For\nsuch devices, ad_sd_read_reg() skips the address byte entirely and clocks\nraw MISO bytes with no address phase — making it byte-for-byte identical\nto reading conversion data. If a pending conversion result is present,\nthis partially consumes it and corrupts the data stream for the subsequent\nad_sd_read_reg() call in ad_sigma_delta_single_conversion().\n\nFurthermore, with num_resetclks = 0 on these devices, data_read_len\nevaluates to 0. If the clocked byte has bit 7 clear, pending_event is set\nand the code attempts memset(data + 2, 0xff, 0 - 1), overflowing to\nSIZE_MAX and corrupting the heap.\n\nFix by returning 0 immediately when neither rdy_gpiod nor has_registers\nis set. This is safe for all current registerless devices: ad7191 and\nad7780 (with powerdown GPIO) are reset between conversions by CS\ndeassertion, so there is no stale result to drain; ad7780 (without\npowerdown GPIO) and max11205 are continuously-converting and cycle ~DRDY\nat the output data rate regardless of whether the previous result was\nread, so the next falling edge fires naturally.\n\nA future registerless device that holds ~DRDY asserted until data is read\nwould be broken by this early return and would require either\nnum_resetclks set or a rdy-gpio.\n\nThe same heap corruption is reachable on any device with rdy_gpiod set\nbut num_resetclks = 0: if the GPIO indicates a pending event, the drain\npath executes memset(data + 2, 0xff, 0 - 1) regardless of has_registers.\nAdd an explicit data_read_len == 0 guard after the pending event check;\nthe stale result is then consumed by the first ad_sd_read_reg() call in\nad_sigma_delta_single_conversion()." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - An attacker reaches the flaw locally by reading a world-readable IIO raw sysfs attribute, which invokes the vulnerable conversion path through read(2). No network or physical-device insertion path is required.\nAC:L - Continuously converting MAX11205 and AD7780 deployments naturally produce the pending result needed to trigger the size underflow. Repeated reads or attacker-controlled interruption of a conversion make the condition reproducible without an uncontrollable race.\nPR:L - IIO raw attributes are created with mode 0444, and the read path performs no capability, authentication, or namespace privilege check. A basic unprivileged local user is sufficient.\nUI:N - The attacker directly reads the sensor attribute and does not require another user to perform any action.\nS:U - The vulnerable driver and the affected kernel resources belong to the same operating-system security authority. Kernel privilege escalation does not itself constitute a scope change.\nC:H - The one-byte allocation is followed by an effectively unbounded heap overwrite, allowing adjacent kernel objects to be corrupted. Heap grooming and concurrent use of corrupted objects could yield control-flow or memory-disclosure primitives exposing arbitrary kernel and process data.\nI:H - The massive out-of-bounds write can corrupt arbitrary adjacent kernel objects and potentially enable control-flow hijacking or privilege escalation.\nA:H - A trigger can cause a fortification panic, kernel page fault or oops, or catastrophic heap corruption, and an unprivileged attacker can repeat it." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/iio/adc/ad_sigma_delta.c" ], "versions": [ { "version": "132d44dc6966c1cf841ffe0f6f048165687e870b", "lessThan": "3394e0b3328422431cadaf314fa58d3717ed4936", "status": "affected", "versionType": "git" }, { "version": "132d44dc6966c1cf841ffe0f6f048165687e870b", "lessThan": "3bceb26dfaf7ba805b459e41c1d0ba916862dade", "status": "affected", "versionType": "git" }, { "version": "132d44dc6966c1cf841ffe0f6f048165687e870b", "lessThan": "91bc6767a4f55dc470d8a56b55b9f2ea09094efe", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/iio/adc/ad_sigma_delta.c" ], "versions": [ { "version": "6.14", "status": "affected" }, { "version": "0", "lessThan": "6.14", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.14", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/3394e0b3328422431cadaf314fa58d3717ed4936" }, { "url": "https://git.kernel.org/stable/c/3bceb26dfaf7ba805b459e41c1d0ba916862dade" }, { "url": "https://git.kernel.org/stable/c/91bc6767a4f55dc470d8a56b55b9f2ea09094efe" } ], "title": "iio: adc: ad_sigma_delta: fix clear_pending_event for registerless devices", "x_generator": { "engine": "bippy-1.2.0" } } } }