FKIE_CVE-2026-72068

Vulnerability from fkie_nvd - Published: 2026-08-15 06:21 - Updated: 2026-08-17 06:18
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved: posix-cpu-timers: Use u64 multiplication in update_rlimit_cpu() update_rlimit_cpu() converts the RLIMIT_CPU value to nanoseconds with u64 nsecs = rlim_new * NSEC_PER_SEC; On 32-bit kernels both rlim_new (unsigned long) and NSEC_PER_SEC (1000000000L) are 32-bit, so the multiplication is performed in unsigned long and truncated for rlim_new > 4 seconds before being widened to u64. The same file already casts to u64 for the matching computation in check_process_timers(): u64 softns = (u64)soft * NSEC_PER_SEC; As a result, the truncated value is installed into the CPUCLOCK_PROF expiry cache (nextevt), causing the process CPU timer to be programmed to fire prematurely for any RLIMIT_CPU soft limit >= 5 seconds. The actual SIGXCPU/SIGKILL decision in check_process_timers() already casts to u64 and is therefore correct, so limit enforcement is not broken; only the expiry-cache programming is wrong. Apply the same cast here so both paths convert rlim_cur identically. 64-bit kernels are unaffected.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1fafc4d9b411645eb34de43362b966dc8fb3e263
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/26aff38fefb1d6cd87e22525f41cc8f1aa61b24f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/384628d6cdde0fcd76868606fad3ad8293100afb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/571e1f10b5996ba3e4dc63ea77de4aa309c384ce
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/cff8281bacd2866767e6194c3079d33b6c5a74f4
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ea6a188ee805e841a0e242f14d15953e0dfa74bb
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/edf6babb9edd2d3e19229ade339081f439d4f478
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/feb5c87c8514444ba891b75a5a3eae57c64edaf8
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/time/posix-cpu-timers.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "feb5c87c8514444ba891b75a5a3eae57c64edaf8",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "384628d6cdde0fcd76868606fad3ad8293100afb",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "1fafc4d9b411645eb34de43362b966dc8fb3e263",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "cff8281bacd2866767e6194c3079d33b6c5a74f4",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "edf6babb9edd2d3e19229ade339081f439d4f478",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "ea6a188ee805e841a0e242f14d15953e0dfa74bb",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "571e1f10b5996ba3e4dc63ea77de4aa309c384ce",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            },
            {
              "lessThan": "26aff38fefb1d6cd87e22525f41cc8f1aa61b24f",
              "status": "affected",
              "version": "858cf3a8c59968e7c5f7c1a1192459a0d52d1ab4",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/time/posix-cpu-timers.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "4.11"
            },
            {
              "lessThan": "4.11",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.97",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nposix-cpu-timers: Use u64 multiplication in update_rlimit_cpu()\n\nupdate_rlimit_cpu() converts the RLIMIT_CPU value to nanoseconds with\n\n        u64 nsecs = rlim_new * NSEC_PER_SEC;\n\nOn 32-bit kernels both rlim_new (unsigned long) and NSEC_PER_SEC\n(1000000000L) are 32-bit, so the multiplication is performed in unsigned\nlong and truncated for rlim_new \u003e 4 seconds before being widened to u64.\n\nThe same file already casts to u64 for the matching computation in\ncheck_process_timers():\n\n        u64 softns = (u64)soft * NSEC_PER_SEC;\n\nAs a result, the truncated value is installed into the CPUCLOCK_PROF\nexpiry cache (nextevt), causing the process CPU timer to be programmed\nto fire prematurely for any RLIMIT_CPU soft limit \u003e= 5 seconds. The\nactual SIGXCPU/SIGKILL decision in check_process_timers() already casts\nto u64 and is therefore correct, so limit enforcement is not broken;\nonly the expiry-cache programming is wrong. Apply the same cast here so\nboth paths convert rlim_cur identically.\n\n64-bit kernels are unaffected."
    }
  ],
  "id": "CVE-2026-72068",
  "lastModified": "2026-08-17T06:18:05.303",
  "metrics": {},
  "published": "2026-08-15T06:21:16.467",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1fafc4d9b411645eb34de43362b966dc8fb3e263"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/26aff38fefb1d6cd87e22525f41cc8f1aa61b24f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/384628d6cdde0fcd76868606fad3ad8293100afb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/571e1f10b5996ba3e4dc63ea77de4aa309c384ce"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/cff8281bacd2866767e6194c3079d33b6c5a74f4"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ea6a188ee805e841a0e242f14d15953e0dfa74bb"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/edf6babb9edd2d3e19229ade339081f439d4f478"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/feb5c87c8514444ba891b75a5a3eae57c64edaf8"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Drag nodes to arrange them. Double-click a related vulnerability to open it, or a source to visit its link. The Physics button on the left tunes the layout and the simulation; the legend at the bottom left hides or shows nodes by kind and by sighting type.

Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

JSON

Loading timeline…




    Related by attack behaviour

    Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.