{"id":"CVE-2026-89628","summary":"HID: picolcd: clamp eeprom debugfs read to bytes actually received","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nHID: picolcd: clamp eeprom debugfs read to bytes actually received\n\npicolcd_debug_eeprom_read() trusts resp-\u003eraw_data[2] -- a length byte\nsupplied by the device in its REPORT_EE_DATA reply -- clamped only to\nthe caller's read() count:\n\n\tret = resp-\u003eraw_data[2];\n\tif (ret \u003e s)\n\t\tret = s;\n\tif (copy_to_user(u, resp-\u003eraw_data+3, ret))\n\nIt never checks resp-\u003eraw_size, the number of bytes picolcd_raw_event()\nactually copied into the 64-byte raw_data[] of the kmalloc'd struct\npicolcd_pending. A device (or a spoofed picoLCD) returning a length byte\nof 0xff, read with a count \u003e= 255, makes copy_to_user() read past\nraw_data[] into adjacent slab memory and return it to userspace through\nthe debugfs \"eeprom\" file:\n\n\tBUG: KASAN: slab-out-of-bounds in _copy_to_user\n\tRead of size 255 ... picolcd_debug_eeprom_read+0x214/0x2f0 [hid_picolcd]\n\nThe debug-dump path in the same file already validates the device length\nbyte against the received size before trusting it; this read does not.\nThe file is created S_IRUSR (root-only) and a crafted device is needed,\nso it is neither unprivileged- nor remotely-triggerable.\n\nClamp the copy length to resp-\u003eraw_size - 3 (the payload actually\nreceived, minus the 3-byte header), floored at 0 for short replies.","modified":"2026-09-13T03:47:20.130321989Z","published":"2026-09-11T19:45:24.203Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89628.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/471f4a939c66d1d44aece2321807abf609fc9098"},{"type":"WEB","url":"https://git.kernel.org/stable/c/699a3c8b56e168ca19d12722f3f5ef1d6f4b1d84"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a3e6e8d7198a9f3861861520a38b673684a1062b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e9c667395ac1f8024f623250b32bae4c7af9caa0"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89628.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-89628"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba"},{"fixed":"a3e6e8d7198a9f3861861520a38b673684a1062b"},{"fixed":"471f4a939c66d1d44aece2321807abf609fc9098"},{"fixed":"699a3c8b56e168ca19d12722f3f5ef1d6f4b1d84"},{"fixed":"e9c667395ac1f8024f623250b32bae4c7af9caa0"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89628.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"2.6.35"},{"fixed":"6.12.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.2.4"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89628.json"}}],"schema_version":"1.9.0"}