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FKIE_CVE-2026-74256

Vulnerability from fkie_nvd - Published: 2026-08-15 06:22 - Updated: 2026-08-17 06:19
Summary
In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check start and len are u32, so u64 last = start + len; evaluates start + len in 32-bit and wraps before storing it in last. The bounds check if (start >= offset + l || last > msg->sg.size) return -EINVAL; can then be passed with an out-of-range start/len, after which the pop loop runs off the end of the scatterlist and sk_msg_shift_left() calls put_page() on the empty msg->sg.end slot: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] RIP: 0010:sk_msg_shift_left net/core/filter.c:2957 [inline] RIP: 0010:____bpf_msg_pop_data net/core/filter.c:3103 [inline] RIP: 0010:bpf_msg_pop_data+0x753/0x1a10 net/core/filter.c:2984 Call Trace: <TASK> bpf_prog_4cc92c278f4d5d56+0x1b1/0x1e8 bpf_prog_run_pin_on_cpu+0x107/0x320 include/linux/filter.h:746 sk_psock_msg_verdict+0x357/0x7f0 net/core/skmsg.c:934 tcp_bpf_send_verdict net/ipv4/tcp_bpf.c:420 [inline] tcp_bpf_sendmsg+0x766/0x1ae0 net/ipv4/tcp_bpf.c:583 __sock_sendmsg+0x153/0x1c0 net/socket.c:802 __sys_sendto+0x326/0x430 net/socket.c:2265 __x64_sys_sendto+0xe3/0x100 net/socket.c:2268 do_syscall_64+0x14c/0x480 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> Widen the addition with a (u64) cast so the bound is evaluated in 64-bit and a len near U32_MAX no longer wraps below msg->sg.size. While here, change pop from int to u32. It counts bytes against the unsigned scatterlist lengths and can never be negative, so the signed type only invites sign-confusion in the pop loop.
Impacted products
Vendor Product Version

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/core/filter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "9ef44ed6fb0c1db01cfcc3de432a33e719713eb5",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "d693c5ed67dabe1ccbf8dcea93075bdc9ffd4ca0",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "ba5cc05dae8fce237d191c7ea96b1107a791e548",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "c05a0ec1cdced622a1a0c7d85679fe02f31033ec",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "17eb9832a10db2f7a80cb429ca2bc5038445a943",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "fe09dd288722f1c749b7506c0b3e7841a7d85027",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "e09f7bd7273928b4089e6b71f8e992f2b356ca1b",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            },
            {
              "lessThan": "a48802fb2cd2d1e23651989f8ff4d15e9d5dad54",
              "status": "affected",
              "version": "7246d8ed4dcce23f7509949a77be15fa9f0e3d28",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/core/filter.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "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\nbpf, sockmap: fix integer overflow in bpf_msg_pop_data() bounds check\n\nstart and len are u32, so\n\n\tu64 last = start + len;\n\nevaluates start + len in 32-bit and wraps before storing it in last.\nThe bounds check\n\n\tif (start \u003e= offset + l || last \u003e msg-\u003esg.size)\n\t\treturn -EINVAL;\n\ncan then be passed with an out-of-range start/len, after which the pop\nloop runs off the end of the scatterlist and sk_msg_shift_left() calls\nput_page() on the empty msg-\u003esg.end slot:\n\n  Oops: general protection fault, probably for non-canonical address\n  0xdffffc0000000001: 0000 [#1] SMP KASAN PTI\n  KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]\n  RIP: 0010:sk_msg_shift_left net/core/filter.c:2957 [inline]\n  RIP: 0010:____bpf_msg_pop_data net/core/filter.c:3103 [inline]\n  RIP: 0010:bpf_msg_pop_data+0x753/0x1a10 net/core/filter.c:2984\n  Call Trace:\n   \u003cTASK\u003e\n   bpf_prog_4cc92c278f4d5d56+0x1b1/0x1e8\n   bpf_prog_run_pin_on_cpu+0x107/0x320 include/linux/filter.h:746\n   sk_psock_msg_verdict+0x357/0x7f0 net/core/skmsg.c:934\n   tcp_bpf_send_verdict net/ipv4/tcp_bpf.c:420 [inline]\n   tcp_bpf_sendmsg+0x766/0x1ae0 net/ipv4/tcp_bpf.c:583\n   __sock_sendmsg+0x153/0x1c0 net/socket.c:802\n   __sys_sendto+0x326/0x430 net/socket.c:2265\n   __x64_sys_sendto+0xe3/0x100 net/socket.c:2268\n   do_syscall_64+0x14c/0x480\n   entry_SYSCALL_64_after_hwframe+0x77/0x7f\n   \u003c/TASK\u003e\n\nWiden the addition with a (u64) cast so the bound is evaluated in\n64-bit and a len near U32_MAX no longer wraps below msg-\u003esg.size.\n\nWhile here, change pop from int to u32. It counts bytes against the\nunsigned scatterlist lengths and can never be negative, so the signed\ntype only invites sign-confusion in the pop loop."
    }
  ],
  "id": "CVE-2026-74256",
  "lastModified": "2026-08-17T06:19:18.920",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.4,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-08-15T06:22:24.743",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/17eb9832a10db2f7a80cb429ca2bc5038445a943"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9ef44ed6fb0c1db01cfcc3de432a33e719713eb5"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a48802fb2cd2d1e23651989f8ff4d15e9d5dad54"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ba5cc05dae8fce237d191c7ea96b1107a791e548"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/c05a0ec1cdced622a1a0c7d85679fe02f31033ec"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/d693c5ed67dabe1ccbf8dcea93075bdc9ffd4ca0"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e09f7bd7273928b4089e6b71f8e992f2b356ca1b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/fe09dd288722f1c749b7506c0b3e7841a7d85027"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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