{"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"}}}}