FKIE_CVE-2026-31630

Vulnerability from fkie_nvd - Published: 2026-04-24 15:16 - Updated: 2026-04-24 17:51
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: rxrpc: proc: size address buffers for %pISpc output The AF_RXRPC procfs helpers format local and remote socket addresses into fixed 50-byte stack buffers with "%pISpc". That is too small for the longest current-tree IPv6-with-port form the formatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a dotted-quad tail not only for v4mapped addresses, but also for ISATAP addresses via ipv6_addr_is_isatap(). As a result, a case such as [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535 is possible with the current formatter. That is 50 visible characters, so 51 bytes including the trailing NUL, which does not fit in the existing char[50] buffers used by net/rxrpc/proc.c. Size the buffers from the formatter's maximum textual form and switch the call sites to scnprintf(). Changes since v1: - correct the changelog to cite the actual maximum current-tree case explicitly - frame the proof around the ISATAP formatting path instead of the earlier mapped-v4 example
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9
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{
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nrxrpc: proc: size address buffers for %pISpc output\n\nThe AF_RXRPC procfs helpers format local and remote socket addresses into\nfixed 50-byte stack buffers with \"%pISpc\".\n\nThat is too small for the longest current-tree IPv6-with-port form the\nformatter can produce. In lib/vsprintf.c, the compressed IPv6 path uses a\ndotted-quad tail not only for v4mapped addresses, but also for ISATAP\naddresses via ipv6_addr_is_isatap().\n\nAs a result, a case such as\n\n  [ffff:ffff:ffff:ffff:0:5efe:255.255.255.255]:65535\n\nis possible with the current formatter. That is 50 visible characters, so\n51 bytes including the trailing NUL, which does not fit in the existing\nchar[50] buffers used by net/rxrpc/proc.c.\n\nSize the buffers from the formatter\u0027s maximum textual form and switch the\ncall sites to scnprintf().\n\nChanges since v1:\n- correct the changelog to cite the actual maximum current-tree case\n  explicitly\n- frame the proof around the ISATAP formatting path instead of the earlier\n  mapped-v4 example"
    }
  ],
  "id": "CVE-2026-31630",
  "lastModified": "2026-04-24T17:51:40.810",
  "metrics": {},
  "published": "2026-04-24T15:16:42.323",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/10ebed83f9f6414af4e85bc85ffaeda7effdd874"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a44ce6aa2efb61fe44f2cfab72bb01544bbca272"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/db297c78ce537c9ac96f0eda9b25ad72c8caefa9"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Awaiting Analysis"
}


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