{"id":"CVE-2026-64083","state":"PUBLISHED","title":"hwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors\n\nadm1266_gpio_get() and adm1266_gpio_get_multiple() both compose the\npin-status word as\n\n\tpins_status = read_buf[0] + (read_buf[1] << 8);\n\nright after i2c_smbus_read_block_data(), guarding only against an\nerror return.  A well-behaved device returns 2 bytes for\nGPIO_STATUS/PDIO_STATUS, but the helper happily reports a 0- or\n1-byte response too.  If the device returns 0 bytes, both read_buf\nslots are uninitialized stack memory; if it returns 1 byte, read_buf[1]\nis.\n\nThe composed value then flows through set_bit() into the caller's\n*bits in adm1266_gpio_get_multiple(), or into the return value of\nadm1266_gpio_get(), and ends up in userspace via gpiolib (sysfs and\nthe char-dev ioctls).  That leaks a few bits of kernel stack per\nrequest on any device whose firmware glitch, bus error, or hostile\nslave produces a short block-read response.\n\nAdd the missing length check to both call sites and surface a short\nresponse as -EIO.","publishedAt":"2026-07-19T15:39:54.756Z","updatedAt":"2026-07-19T15:39:54.756Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"fd9196aad9e5a3845cea17de3405ebc700382142","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"ee4799becf7d2af3778007e22c2e55c4009a49c7","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"c603b6c6840ac0c6285f5eefea0de6242710af21","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"a2d1c819348b36fccbbfcf37c5fa7a50a9b4528f","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"ae25cf2ea9ebd06d7ad416647dbdc7b5d0172946","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"eb3cd9bb590460c6127145cb245be925d23f5232","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"64fa9328948ddcc0f7f3c23ea1756c126d9dffac","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"a7232f68c43ca62f545049b7f5fbfc75137b843b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hwmon/pmbus/adm1266.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hwmon/pmbus/adm1266.c"]}],"references":["https://git.kernel.org/stable/c/fd9196aad9e5a3845cea17de3405ebc700382142","https://git.kernel.org/stable/c/ee4799becf7d2af3778007e22c2e55c4009a49c7","https://git.kernel.org/stable/c/c603b6c6840ac0c6285f5eefea0de6242710af21","https://git.kernel.org/stable/c/a2d1c819348b36fccbbfcf37c5fa7a50a9b4528f","https://git.kernel.org/stable/c/ae25cf2ea9ebd06d7ad416647dbdc7b5d0172946","https://git.kernel.org/stable/c/eb3cd9bb590460c6127145cb245be925d23f5232","https://git.kernel.org/stable/c/64fa9328948ddcc0f7f3c23ea1756c126d9dffac","https://git.kernel.org/stable/c/a7232f68c43ca62f545049b7f5fbfc75137b843b"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64083.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64083","state":"PUBLISHED","datePublished":"2026-07-19T15:39:54.756Z","dateUpdated":"2026-07-19T15:39:54.756Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.031Z"},"containers":{"cna":{"title":"hwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nhwmon: (pmbus/adm1266) reject short block-read responses in the GPIO accessors\n\nadm1266_gpio_get() and adm1266_gpio_get_multiple() both compose the\npin-status word as\n\n\tpins_status = read_buf[0] + (read_buf[1] << 8);\n\nright after i2c_smbus_read_block_data(), guarding only against an\nerror return.  A well-behaved device returns 2 bytes for\nGPIO_STATUS/PDIO_STATUS, but the helper happily reports a 0- or\n1-byte response too.  If the device returns 0 bytes, both read_buf\nslots are uninitialized stack memory; if it returns 1 byte, read_buf[1]\nis.\n\nThe composed value then flows through set_bit() into the caller's\n*bits in adm1266_gpio_get_multiple(), or into the return value of\nadm1266_gpio_get(), and ends up in userspace via gpiolib (sysfs and\nthe char-dev ioctls).  That leaks a few bits of kernel stack per\nrequest on any device whose firmware glitch, bus error, or hostile\nslave produces a short block-read response.\n\nAdd the missing length check to both call sites and surface a short\nresponse as -EIO."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"fd9196aad9e5a3845cea17de3405ebc700382142","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"ee4799becf7d2af3778007e22c2e55c4009a49c7","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"c603b6c6840ac0c6285f5eefea0de6242710af21","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"a2d1c819348b36fccbbfcf37c5fa7a50a9b4528f","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"ae25cf2ea9ebd06d7ad416647dbdc7b5d0172946","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"eb3cd9bb590460c6127145cb245be925d23f5232","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"64fa9328948ddcc0f7f3c23ea1756c126d9dffac","versionType":"git"},{"version":"d98dfad35c38c037b37c4adc99df01da571031a5","status":"affected","lessThan":"a7232f68c43ca62f545049b7f5fbfc75137b843b","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hwmon/pmbus/adm1266.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.10","versionType":"semver"},{"version":"5.10.258","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.209","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.175","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.142","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.92","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.34","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/hwmon/pmbus/adm1266.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/fd9196aad9e5a3845cea17de3405ebc700382142"},{"url":"https://git.kernel.org/stable/c/ee4799becf7d2af3778007e22c2e55c4009a49c7"},{"url":"https://git.kernel.org/stable/c/c603b6c6840ac0c6285f5eefea0de6242710af21"},{"url":"https://git.kernel.org/stable/c/a2d1c819348b36fccbbfcf37c5fa7a50a9b4528f"},{"url":"https://git.kernel.org/stable/c/ae25cf2ea9ebd06d7ad416647dbdc7b5d0172946"},{"url":"https://git.kernel.org/stable/c/eb3cd9bb590460c6127145cb245be925d23f5232"},{"url":"https://git.kernel.org/stable/c/64fa9328948ddcc0f7f3c23ea1756c126d9dffac"},{"url":"https://git.kernel.org/stable/c/a7232f68c43ca62f545049b7f5fbfc75137b843b"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-07-19T15:39:54.756Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.10.258"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.6.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.12.92"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"6.18.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}