{
  "schemaVersion": 1,
  "attribution": [
    {
      "source": "CISA Known Exploited Vulnerabilities",
      "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog",
      "licence": "US government work"
    },
    {
      "source": "GitHub Advisory Database",
      "url": "https://github.com/advisories",
      "licence": "CC BY 4.0"
    },
    {
      "source": "Have I Been Pwned",
      "url": "https://haveibeenpwned.com/",
      "licence": "CC BY 4.0"
    },
    {
      "source": "CVE Program (CVE records)",
      "url": "https://www.cve.org/Legal/TermsOfUse",
      "licence": "CVE Terms of Use",
      "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.",
      "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy."
    },
    {
      "source": "FIRST EPSS",
      "url": "https://www.first.org/epss/",
      "licence": "free to use; FIRST requests attribution"
    }
  ],
  "record": {
    "id": "CVE-2025-39758",
    "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2025-39758",
    "idYear": 2025,
    "status": "PUBLISHED",
    "publishedAt": "2025-09-11T16:52:27.598Z",
    "updatedAt": "2026-08-23T12:45:23.784Z",
    "importedAt": "2026-10-24T01:57:34.152Z",
    "snapshot": {
      "id": "cve_2026-10-24_midnight_baseline",
      "at": "2026-10-24T00:00:00.000Z",
      "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z"
    },
    "facts": {
      "title": "RDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages",
      "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/siw: Fix the sendmsg byte count in siw_tcp_sendpages\n\nEver since commit c2ff29e99a76 (\"siw: Inline do_tcp_sendpages()\"),\nwe have been doing this:\n\nstatic int siw_tcp_sendpages(struct socket *s, struct page **page, int offset,\n                             size_t size)\n[...]\n        /* Calculate the number of bytes we need to push, for this page\n         * specifically */\n        size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);\n        /* If we can't splice it, then copy it in, as normal */\n        if (!sendpage_ok(page[i]))\n                msg.msg_flags &= ~MSG_SPLICE_PAGES;\n        /* Set the bvec pointing to the page, with len $bytes */\n        bvec_set_page(&bvec, page[i], bytes, offset);\n        /* Set the iter to $size, aka the size of the whole sendpages (!!!) */\n        iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, size);\ntry_page_again:\n        lock_sock(sk);\n        /* Sendmsg with $size size (!!!) */\n        rv = tcp_sendmsg_locked(sk, &msg, size);\n\nThis means we've been sending oversized iov_iters and tcp_sendmsg calls\nfor a while. This has a been a benign bug because sendpage_ok() always\nreturned true. With the recent slab allocator changes being slowly\nintroduced into next (that disallow sendpage on large kmalloc\nallocations), we have recently hit out-of-bounds crashes, due to slight\ndifferences in iov_iter behavior between the MSG_SPLICE_PAGES and\n\"regular\" copy paths:\n\n(MSG_SPLICE_PAGES)\nskb_splice_from_iter\n  iov_iter_extract_pages\n    iov_iter_extract_bvec_pages\n      uses i->nr_segs to correctly stop in its tracks before OoB'ing everywhere\n  skb_splice_from_iter gets a \"short\" read\n\n(!MSG_SPLICE_PAGES)\nskb_copy_to_page_nocache copy=iov_iter_count\n [...]\n   copy_from_iter\n        /* this doesn't help */\n        if (unlikely(iter->count < len))\n                len = iter->count;\n          iterate_bvec\n            ... and we run off the bvecs\n\nFix this by properly setting the iov_iter's byte count, plus sending the\ncorrect byte count to tcp_sendmsg_locked.",
      "affected": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "versions": [
            {
              "version": "a19a58ab12695abb91a4e8ecf62cc0bc5badefbe",
              "status": "affected",
              "versionType": "git",
              "lessThan": "b47c4b7cb78b6382c6d1af0bfc0d8218e4f445cc"
            },
            {
              "version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "5661fdd218c2799001b88c17acd19f4395e4488e"
            },
            {
              "version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "673cf582fd788af12cdacfb62a6a593083542481"
            },
            {
              "version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "42ebc16d9d2563f1a1ce0f05b643ee68d54fabf8"
            },
            {
              "version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "edf82bc8150570167a33a7d54627d66614cbf841"
            },
            {
              "version": "c2ff29e99a764769eb2ce3a1a5585013633ee9a6",
              "status": "affected",
              "versionType": "git",
              "lessThan": "c18646248fed07683d4cee8a8af933fc4fe83c0d"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "versions": [
            {
              "version": "6.5",
              "status": "affected"
            },
            {
              "version": "0",
              "status": "unaffected",
              "versionType": "semver",
              "lessThan": "6.5"
            },
            {
              "version": "6.6.103",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.6.*"
            },
            {
              "version": "6.12.43",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.12.*"
            },
            {
              "version": "6.15.11",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.15.*"
            },
            {
              "version": "6.16.2",
              "status": "unaffected",
              "versionType": "semver",
              "lessThanOrEqual": "6.16.*"
            },
            {
              "version": "6.17",
              "status": "unaffected",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ]
        }
      ]
    }
  }
}