CVE-2026-31751

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