CVE-2024-44950

2024-09-0419:15:30

Linux

web.nvd.nist.gov

linux kernel vulnerability

sc16is7xx driver

special register set

fifo access

AI Score

7.1

Confidence

Low

EPSS

Percentile

9.6%

JSON

In the Linux kernel, the following vulnerability has been resolved:

serial: sc16is7xx: fix invalid FIFO access with special register set

When enabling access to the special register set, Receiver time-out and
RHR interrupts can happen. In this case, the IRQ handler will try to read
from the FIFO thru the RHR register at address 0x00, but address 0x00 is
mapped to DLL register, resulting in erroneous FIFO reading.

Call graph example:
sc16is7xx_startup(): entry
sc16is7xx_ms_proc(): entry
sc16is7xx_set_termios(): entry
sc16is7xx_set_baud(): DLH/DLL = $009C –> access special register set
sc16is7xx_port_irq() entry –> IIR is 0x0C
sc16is7xx_handle_rx() entry
sc16is7xx_fifo_read(): –> unable to access FIFO (RHR) because it is
mapped to DLL (LCR=LCR_CONF_MODE_A)
sc16is7xx_set_baud(): exit –> Restore access to general register set

Fix the problem by claiming the efr_lock mutex when accessing the Special
register set.

Affected configurations

Vulners

Node

linuxlinux_kernelRange3.16–6.10.5

linuxlinux_kernelRange6.11.0≥

VendorProductVersionCPE
linuxlinux_kernel*cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*

Vendor	Product	Version	CPE
linux	linux_kernel	*	cpe:2.3:o:linux:linux_kernel::::::::

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/tty/serial/sc16is7xx.c"
    ],
    "versions": [
      {
        "version": "dfeae619d781",
        "lessThan": "6a6730812220",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "dfeae619d781",
        "lessThan": "7d3b793faaab",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/tty/serial/sc16is7xx.c"
    ],
    "versions": [
      {
        "version": "3.16",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "3.16",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.10.5",
        "lessThanOrEqual": "6.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.11",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]