CVE-2024-35793 debugfs: fix wait/cancellation handling during remove

2024-05-1712:24:56

Linux

www.cve.org

linux kernel

debugfs

vulnerability

fix

wait/cancellation

concurrent

deadlock

access

AI Score

7.5

Confidence

High

EPSS

Percentile

15.5%

JSON

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

debugfs: fix wait/cancellation handling during remove

Ben Greear further reports deadlocks during concurrent debugfs
remove while files are being accessed, even though the code in
question now uses debugfs cancellations. Turns out that despite
all the review on the locking, we missed completely that the
logic is wrong: if the refcount hits zero we can finish (and
need not wait for the completion), but if it doesn’t we have
to trigger all the cancellations. As written, we can never
get into the loop triggering the cancellations. Fix this, and
explain it better while at it.

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/debugfs/inode.c"
    ],
    "versions": [
      {
        "version": "8c88a474357e",
        "lessThan": "e88b5ae01901",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8c88a474357e",
        "lessThan": "3d08cca5fd0a",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "8c88a474357e",
        "lessThan": "952c3fce297f",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "fs/debugfs/inode.c"
    ],
    "versions": [
      {
        "version": "6.7",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "6.7",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.7.12",
        "lessThanOrEqual": "6.7.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.8.3",
        "lessThanOrEqual": "6.8.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "6.9",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]