CyberRota Analysis
AI-GeneratedThe vulnerability in the Linux kernel affects the picolcd driver, where the function picolcd_debug_eeprom_read() improperly trusts a length byte from the device, leading to potential out-of-bounds memory reads. This flaw allows a malicious or spoofed picoLCD device to exploit the debugfs "eeprom" file, potentially exposing sensitive data from adjacent memory. System administrators and security teams managing Linux environments with picoLCD devices should prioritize this issue, particularly those with root access, to mitigate the risk of unauthorized data exposure.
Original NVD Description
In the Linux kernel, the following vulnerability has been resolved: HID: picolcd: clamp eeprom debugfs read to bytes actually received picolcd_debug_eeprom_read() trusts resp->raw_data[2] -- a length byte supplied by the device in its REPORT_EE_DATA reply -- clamped only to the caller's read() count: ret = resp->raw_data[2]; if (ret > s) ret = s; if (copy_to_user(u, resp->raw_data+3, ret)) It never checks resp->raw_size, the number of bytes picolcd_raw_event() actually copied into the 64-byte raw_data[] of the kmalloc'd struct picolcd_pending. A device (or a spoofed picoLCD) returning a length byte of 0xff, read with a count >= 255, makes copy_to_user() read past raw_data[] into adjacent slab memory and return it to userspace through the debugfs "eeprom" file: BUG: KASAN: slab-out-of-bounds in _copy_to_user Read of size 255 ... picolcd_debug_eeprom_read+0x214/0x2f0 [hid_picolcd] The debug-dump path in the same file already validates the device length byte against the received size before trusting it; this read does not. The file is created S_IRUSR (root-only) and a crafted device is needed, so it is neither unprivileged- nor remotely-triggerable. Clamp the copy length to resp->raw_size - 3 (the payload actually received, minus the 3-byte header), floored at 0 for short replies.