FKIE_CVE-2026-43405

Vulnerability from fkie_nvd - Published: 2026-05-08 15:16 - Updated: 2026-05-21 19:16
Severity
7.5 (High) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: libceph: Use u32 for non-negative values in ceph_monmap_decode() This patch fixes unnecessary implicit conversions that change signedness of blob_len and num_mon in ceph_monmap_decode(). Currently blob_len and num_mon are (signed) int variables. They are used to hold values that are always non-negative and get assigned in ceph_decode_32_safe(), which is meant to assign u32 values. Both variables are subsequently used as unsigned values, and the value of num_mon is further assigned to monmap->num_mon, which is of type u32. Therefore, both variables should be of type u32. This is especially relevant for num_mon. If the value read from the incoming message is very large, it is interpreted as a negative value, and the check for num_mon > CEPH_MAX_MON does not catch it. This leads to the attempt to allocate a very large chunk of memory for monmap, which will most likely fail. In this case, an unnecessary attempt to allocate memory is performed, and -ENOMEM is returned instead of -EINVAL.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/08bc6173fd611ad5a40f472bf5f15b92aea0fe40Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5f2806684b05bd24d05c091083b8e2517ba8ffacPatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/770444611f047dbfd4517ec0bc1b179d40c2f346Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/86f7060cd638d6eb042e8ed780fb83a59ca0dcb3Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b268984ae88cb0dcd7a8e8263962c748448e26e8Patch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ba0a4df8c563536857dcbf7b4dbd0f2a15f57acePatch
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ee5588e2bc41acb73f6676c0520420c107cd0140Patch
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 7.0
linux linux_kernel 7.0
linux linux_kernel 7.0
To clipboard 

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  "descriptions": [
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      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: Use u32 for non-negative values in ceph_monmap_decode()\n\nThis patch fixes unnecessary implicit conversions that change signedness\nof blob_len and num_mon in ceph_monmap_decode().\nCurrently blob_len and num_mon are (signed) int variables. They are used\nto hold values that are always non-negative and get assigned in\nceph_decode_32_safe(), which is meant to assign u32 values. Both\nvariables are subsequently used as unsigned values, and the value of\nnum_mon is further assigned to monmap-\u003enum_mon, which is of type u32.\nTherefore, both variables should be of type u32. This is especially\nrelevant for num_mon. If the value read from the incoming message is\nvery large, it is interpreted as a negative value, and the check for\nnum_mon \u003e CEPH_MAX_MON does not catch it. This leads to the attempt to\nallocate a very large chunk of memory for monmap, which will most likely\nfail. In this case, an unnecessary attempt to allocate memory is\nperformed, and -ENOMEM is returned instead of -EINVAL."
    }
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  "id": "CVE-2026-43405",
  "lastModified": "2026-05-21T19:16:09.970",
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          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
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        "impactScore": 3.6,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
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  "published": "2026-05-08T15:16:52.013",
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