CVE-2021-47153 i2c: i801: Don't generate an interrupt on bus reset

2024-03-2509:07:47

Linux

github.com

linux kernel

i2c-i801 driver

interrupt handling

6.7 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

13.2%

JSON

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

i2c: i801: Don’t generate an interrupt on bus reset

Now that the i2c-i801 driver supports interrupts, setting the KILL bit
in a attempt to recover from a timed out transaction triggers an
interrupt. Unfortunately, the interrupt handler (i801_isr) is not
prepared for this situation and will try to process the interrupt as
if it was signaling the end of a successful transaction. In the case
of a block transaction, this can result in an out-of-range memory
access.

This condition was reproduced several times by syzbot:
https://syzkaller.appspot.com/bug?extid=ed71512d469895b5b34e
https://syzkaller.appspot.com/bug?extid=8c8dedc0ba9e03f6c79e
https://syzkaller.appspot.com/bug?extid=c8ff0b6d6c73d81b610e
https://syzkaller.appspot.com/bug?extid=33f6c360821c399d69eb
https://syzkaller.appspot.com/bug?extid=be15dc0b1933f04b043a
https://syzkaller.appspot.com/bug?extid=b4d3fd1dfd53e90afd79

So disable interrupts while trying to reset the bus. Interrupts will
be enabled again for the following transaction.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/i2c/busses/i2c-i801.c"
    ],
    "versions": [
      {
        "version": "636752bcb517",
        "lessThan": "f9469082126c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "09c9e79f4c10",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "dfa8929e117b",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "c70e1ba2e7e6",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "04cc05e3716a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "b523feb7e8e4",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "1f583d3813f2",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "636752bcb517",
        "lessThan": "e4d8716c3dce",
        "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/i2c/busses/i2c-i801.c"
    ],
    "versions": [
      {
        "version": "3.6",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "3.6",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.4.271",
        "lessThanOrEqual": "4.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.9.271",
        "lessThanOrEqual": "4.9.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.14.235",
        "lessThanOrEqual": "4.14.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.193",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.124",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.42",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.9",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]