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CVE-2026-89628

HID: picolcd: clamp eeprom debugfs read to bytes actually received

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.109, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

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.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in 1a02056c2bf7ef9b5fd05ee6913aeeadb703c443; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in 65daa322f1021d8206f8032c4cd4c0cb2d26c7c3; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in 8dc662af019158690c470edd2e2857657f700abb; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in 4daf432c94a42e7be6aa10b012b33af5ed9bc118; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in a3e6e8d7198a9f3861861520a38b673684a1062b; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in 471f4a939c66d1d44aece2321807abf609fc9098; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in 699a3c8b56e168ca19d12722f3f5ef1d6f4b1d84; From 9bbf2b98ba11d00bd73e3254e15cfe17ccaff6ba · fixed in e9c667395ac1f8024f623250b32bae4c7af9caa0

  • Linux Linux

    2.6.35

  • KernelLinux

    From 2.6.35 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.109; From 6.13.0 · fixed in 6.18.50; From 6.19.0 · fixed in 7.2.4

References 8

git.kernel.org