{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "fa691d0c9c0812b9045f3a9420862e47b3b92518"
            },
            {
              "fixed": "3b3a552cf88e10bb7bda88b29cf1fd8267043d50"
            },
            {
              "fixed": "5b927dcec5f1087942bf123a82e64a3f66475f01"
            },
            {
              "fixed": "22c1d5ecccf92c849bdca1556179aafc95794baf"
            },
            {
              "fixed": "420aabb32da4381d8d7cdcaa6a77fad9eaceb0a4"
            },
            {
              "fixed": "abc4c56427f144c96b2827a4db3b90eb5b7349a2"
            },
            {
              "fixed": "25f6b929c7e379cbea7cb8caa67b49b2d1efae17"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "5.17.0"
            },
            {
              "fixed": "6.1.178"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.2.0"
            },
            {
              "fixed": "6.6.145"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.7.0"
            },
            {
              "fixed": "6.12.97"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.40"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.1.5"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72343.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix HV VHCA stats zero-sized buffer allocation\n\nmlx5e_hv_vhca_stats_create() is called from mlx5e_nic_enable(),\nbefore mlx5e_open(). At that point priv-\u003estats_nch is still zero,\nbecause it is only ever incremented in mlx5e_channel_stats_alloc(),\nwhich is reached only from mlx5e_open_channel().\n\nmlx5e_hv_vhca_stats_buf_size() therefore returns 0, and\nkvzalloc(0, GFP_KERNEL) returns ZERO_SIZE_PTR ((void *)16) rather\nthan NULL. The \"if (!buf)\" guard does not catch this, and\nmlx5e_hv_vhca_stats_create() completes \"successfully\" with\npriv-\u003estats_agent.buf set to ZERO_SIZE_PTR.\n\nOnce channels are opened (priv-\u003estats_nch \u003e 0) and the hypervisor\nenables stats reporting, mlx5e_hv_vhca_stats_work() recomputes\nbuf_len using the new non-zero stats_nch and calls\nmemset(buf, 0, buf_len) on ZERO_SIZE_PTR, faulting at address 0x10.\n\nAllocate the buffer based on priv-\u003emax_nch, which is set in\nmlx5e_priv_init() and is the upper bound on stats_nch:\n\n  - Add a separate helper mlx5e_hv_vhca_stats_buf_max_size() that\n    returns sizeof(per_ring_stats) * max(max_nch, stats_nch), and\n    use it for the kvzalloc() in mlx5e_hv_vhca_stats_create().\n  - Keep mlx5e_hv_vhca_stats_buf_size() (which returns based on\n    stats_nch) for the worker's active payload size, so the wire\n    format (block-\u003erings = stats_nch) and the amount of data filled\n    by mlx5e_hv_vhca_fill_stats() are unchanged.\n\nThe max(max_nch, stats_nch) guard handles the rare case where\nmlx5e_attach_netdev() recomputes max_nch downward across a\ndetach/resume cycle while priv-\u003estats_nch persists (mlx5e_detach_netdev\ndoes not call mlx5e_priv_cleanup, so stats_nch is only reset when\nthe netdev is destroyed). Without the guard, the worker could compute\nbuf_len from stats_nch and overrun the smaller buffer allocated based\non the reduced max_nch.\n\nAllocating a non-zero buffer also makes the kvzalloc() failure path in\nmlx5e_hv_vhca_stats_create() reachable for the first time: it returns\nearly without (re)creating the agent. Clear\npriv-\u003estats_agent.{agent,buf} in mlx5e_hv_vhca_stats_destroy() after\nfreeing them, so that if a later create() bails out on this path, a\nsubsequent teardown does not double-free the stale agent/buffer left\nfrom a previous enable/disable cycle.\n\nThis mirrors the existing mlx5e pattern of preallocating arrays of\nsize max_nch (e.g. priv-\u003echannel_stats) and lazily populating\nentries up to stats_nch on demand.",
  "id": "CVE-2026-72343",
  "modified": "2026-08-16T03:31:19.497349615Z",
  "published": "2026-08-15T05:55:49.067Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/22c1d5ecccf92c849bdca1556179aafc95794baf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/25f6b929c7e379cbea7cb8caa67b49b2d1efae17"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3b3a552cf88e10bb7bda88b29cf1fd8267043d50"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/420aabb32da4381d8d7cdcaa6a77fad9eaceb0a4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5b927dcec5f1087942bf123a82e64a3f66475f01"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/abc4c56427f144c96b2827a4db3b90eb5b7349a2"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72343.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72343"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "net/mlx5e: Fix HV VHCA stats zero-sized buffer allocation"
}