RDMA/umad: Reject negative data_len in ib_umad_write_CVE-2026-23243

{
    "lastseen": "",
    "description": "In the Linux kernel, the following vulnerability has been resolved:\n\nRDMA/umad: Reject negative data_len in ib_umad_write\n\nib_umad_write computes data_len from user-controlled count and the\nMAD header sizes. With a mismatched user MAD header size and RMPP\nheader length, data_len can become negative and reach ib_create_send_mad().\nThis can make the padding calculation exceed the segment size and trigger\nan out-of-bounds memset in alloc_send_rmpp_list().\n\nAdd an explicit check to reject negative data_len before creating the\nsend buffer.\n\nKASAN splat:\n[  211.363464] BUG: KASAN: slab-out-of-bounds in ib_create_send_mad+0xa01/0x11b0\n[  211.364077] Write of size 220 at addr ffff88800c3fa1f8 by task spray_thread/102\n[  211.365867] ib_create_send_mad+0xa01/0x11b0\n[  211.365887] ib_umad_write+0x853/0x1c80",
    "published": "2026-03-18T10:05:05.826Z",
    "modified": "2026-04-02T14:43:56.668Z",
    "type": "cve",
    "title": "RDMA/umad: Reject negative data_len in ib_umad_write",
    "source": "Linux",
    "references": "https://git.kernel.org/stable/c/1371ef6b1ecf3676b8942f5dfb3634fb0648128e\nhttps://git.kernel.org/stable/c/362e45fd9069ffa1523f9f1633b606ebf72060d7\nhttps://git.kernel.org/stable/c/6eb2919474ca105c5b13d19574e25f0ddcf19ca2\nhttps://git.kernel.org/stable/c/a6a3e4af10993cb9e4b8f0548680aba0ab5f3b0d\nhttps://git.kernel.org/stable/c/9c80d688f402539dfc8f336de1380d6b4ee14316\nhttps://git.kernel.org/stable/c/205955f29c26330b1dc7fdeadd5bb97c38e26f56\nhttps://git.kernel.org/stable/c/52ab82cc5cf8ada5c3fb6ffe8f32fdb2fc27a34b\nhttps://git.kernel.org/stable/c/5551b02fdbfd85a325bb857f3a8f9c9f33397ed2",
    "id": "CVE-2026-23243",
    "bulletinFamily": "",
    "cwe": null,
    "cvelist": null,
    "sourceData": "Linux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2be8e3ee8efd6f99ce454115c29d09750915021a\nLinux Linux 2.6.24",
    "sourceHref": "",
    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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": "2be8e3ee8efd6f99ce454115c29d09750915021a",
    "vendor": "Linux",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}