CVE-2026-31751

MEDIUM

comedi: dt2815: add hardware detection to prevent crash

Title source: cna
STIX 2.1

Description

In the Linux kernel, the following vulnerability has been resolved: comedi: dt2815: add hardware detection to prevent crash The dt2815 driver crashes when attached to I/O ports without actual hardware present. This occurs because syzkaller or users can attach the driver to arbitrary I/O addresses via COMEDI_DEVCONFIG ioctl. When no hardware exists at the specified port, inb() operations return 0xff (floating bus), but outb() operations can trigger page faults due to undefined behavior, especially under race conditions: BUG: unable to handle page fault for address: 000000007fffff90 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page RIP: 0010:dt2815_attach+0x6e0/0x1110 Add hardware detection by reading the status register before attempting any write operations. If the read returns 0xff, assume no hardware is present and fail the attach with -ENODEV. This prevents crashes from outb() operations on non-existent hardware.

Scores

CVSS v3 4.7
EPSS 0.0001
EPSS Percentile 1.8%
Attack Vector LOCAL
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-362
Status published
Products (28)
Linux/Linux < 2.6.30
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 0dcf33994b8dcf3db36530fb7e2cf9f89e5cbac3
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 34b13250c618d7441508c6ef369144aa8a9b9bfa
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 34c8b3a91bdfbe4573650b4cd750ef639101fdc5
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 65c528fbeddd88478c210052f6c7b21be4973156
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 8d63161837f1bf8810dbcd2a583c2bbf5ca6d733
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - 93853512f565e625df2397f0d8050d6aafd7c3ad
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - d2a786efdb9971f2a647724625da5bbecc994dc9
Linux/Linux 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 - d5d9df8b08d68d083ac57abc2c887dfb1f31af63
Linux/Linux 2.6.30
... and 18 more
Published May 01, 2026
Tracked Since May 01, 2026