4.7

CVE-2026-31751

comedi: dt2815: add hardware detection to prevent crash

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 2.6.30 < 5.10.253
Linux ≫ Linux Kernel Version >= 5.11 < 5.15.203
Linux ≫ Linux Kernel Version >= 5.16 < 6.1.168
Linux ≫ Linux Kernel Version >= 6.2 < 6.6.134
Linux ≫ Linux Kernel Version >= 6.7 < 6.12.81
Linux ≫ Linux Kernel Version >= 6.13 < 6.18.22
Linux ≫ Linux Kernel Version >= 6.19 < 6.19.12
Linux ≫ Linux Kernel Version7.0 Updaterc1
Linux ≫ Linux Kernel Version7.0 Updaterc2
Linux ≫ Linux Kernel Version7.0 Updaterc3
Linux ≫ Linux Kernel Version7.0 Updaterc4
Linux ≫ Linux Kernel Version7.0 Updaterc5
Linux ≫ Linux Kernel Version7.0 Updaterc6
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EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.01% 0.017
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 4.7 1 3.6
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.