io_uring/rsrc: reject zero-length fixed buffer import_CVE-2026-43006

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/rsrc: reject zero-length fixed buffer import\n\nvalidate_fixed_range() admits buf_addr at the exact end of the\nregistered region when len is zero, because the check uses strict\ngreater-than (buf_end > imu->ubuf + imu->len).  io_import_fixed()\nthen computes offset == imu->len, which causes the bvec skip logic\nto advance past the last bio_vec entry and read bv_offset from\nout-of-bounds slab memory.\n\nReturn early from io_import_fixed() when len is zero.  A zero-length\nimport has no data to transfer and should not walk the bvec array\nat all.\n\n  BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0\n  Read of size 4 at addr ffff888002bcc254 by task poc/103\n  Call Trace:\n   io_import_reg_buf+0x697/0x7f0\n   io_write_fixed+0xd9/0x250\n   __io_issue_sqe+0xad/0x710\n   io_issue_sqe+0x7d/0x1100\n   io_submit_sqes+0x86a/0x23c0\n   __do_sys_io_uring_enter+0xa98/0x1590\n  Allocated by task 103:\n  The buggy address is located 12 bytes to the right of\n   allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)",
    "published": "2026-05-01T14:15:14.176Z",
    "modified": "2026-05-03T05:46:00.912Z",
    "type": "cve",
    "title": "io_uring/rsrc: reject zero-length fixed buffer import",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/040a1e7e0e2f01851fec1dd2d96906f8636a9f75\nhttps://git.kernel.org/stable/c/40170fc1a79c1b2e68f09ae6aac687b7305ae6f4\nhttps://git.kernel.org/stable/c/111a12b422a8cfa93deabaef26fec48237163214",
    "id": "CVE-2026-43006",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 8622b20f23ed165f48b8ca61503a107d17f8d585\nLinux Linux 8622b20f23ed165f48b8ca61503a107d17f8d585\nLinux Linux 8622b20f23ed165f48b8ca61503a107d17f8d585\nLinux Linux 6.15",
    "sourceHref": "",
    "cvss": {
        "score": 7.1,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Linux",
    "version": "8622b20f23ed165f48b8ca61503a107d17f8d585",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}