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CVE-2026-72341

Estado: RecibidaSin puntuar—

In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: Fix publication race for priv->channel_stats[]

mlx5e_channel_stats_alloc() publishes a new entry to priv->channel_stats[] and then increments priv->stats_nch as a publication token, but neither store carries any memory barrier:

Concurrent readers compute the loop bound from priv->stats_nch and then dereference priv->channel_stats[i] using plain accesses, e.g.

On weakly-ordered architectures (ARM, PowerPC, RISC-V) the writes to channel_stats[ix] and stats_nch may become visible to other CPUs out of program order. A reader can observe stats_nch == N while still seeing channel_stats[N-1] == NULL, leading to a NULL pointer dereference in the channel_stats loop.

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This has been observed in production on BlueField-3 DPUs (arm64), where ovs-vswitchd queries netdev statistics over netlink during NIC bringup, racing mlx5e_open_channel() -> mlx5e_channel_stats_alloc() on another CPU:

Add mlx5e_stats_nch_write() and mlx5e_stats_nch_read() helpers in en.h that wrap the smp_store_release()/smp_load_acquire() pair on stats_nch. The release/acquire pair establishes the contract:

Publish the stats_nch increment via mlx5e_stats_nch_write() in the writer (mlx5e_channel_stats_alloc()), and read stats_nch via mlx5e_stats_nch_read() in all readers: mlx5e RX/TX queue stats, mlx5e_get_base_stats(), ethtool channels stats, IPoIB stats, the sw_stats fold and the HV VHCA stats agent.

Detalles técnicos trazas, registros y código del informe original
	priv->channel_stats[ix] = kvzalloc_node(...);
	if (!priv->channel_stats[ix])
		return -ENOMEM;
	priv->stats_nch++;

	for (i = 0; i < priv->stats_nch; i++) {
		struct mlx5e_channel_stats *cs = priv->channel_stats[i];
		... cs->rq.packets ...
	}

  Unable to handle kernel NULL pointer dereference at virtual address 0x840
  Hardware name: BlueField-3 DPU
  pc : mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]
  Call trace:
   mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]
   dev_get_stats+0x50/0xc0
   ovs_vport_get_stats+0x38/0xac [openvswitch]
   ovs_vport_cmd_fill_info+0x194/0x290 [openvswitch]
   ovs_vport_cmd_get+0xbc/0x10c [openvswitch]
   genl_family_rcv_msg_doit+0xd0/0x160
   genl_rcv_msg+0xec/0x1f0
   netlink_rcv_skb+0x64/0x130
   genl_rcv+0x40/0x60
   netlink_unicast+0x2fc/0x370
   netlink_sendmsg+0x1dc/0x454
   ...
   __arm64_sys_sendmsg+0x2c/0x40

  stats_nch == N  =>  channel_stats[0..N-1] are visible and non-NULL.

CVSS

NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (1)

⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.

Referencias

JSON original (NVD)

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{
  "id": "CVE-2026-72341",
  "cveTags": [],
  "metrics": {},
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
              "lessThan": "5c7e3755abf663f033de24f917b77685e9543045",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
              "lessThan": "815515ec68f527ca755cb1e2c1ff9148f6b3ea56",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "fa691d0c9c0812b9045f3a9420862e47b3b92518",
              "lessThan": "5a799714e8ca0bce9ea40694f49914cf1adbbaa9",
              "versionType": "git"
            }
          ],
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en.h",
            "drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c",
            "drivers/net/ethernet/mellanox/mlx5/core/en_main.c",
            "drivers/net/ethernet/mellanox/mlx5/core/en_stats.c",
            "drivers/net/ethernet/mellanox/mlx5/core/ipoib/ipoib.c"
          ],
          "defaultStatus": "unaffected"
        },
        {
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "product": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.17"
            },
            {
              "status": "unaffected",
              "version": "0",
              "lessThan": "5.17",
              "versionType": "semver"
            },
            {
              "status": "unaffected",
              "version": "6.18.40",
              "versionType": "semver",
              "lessThanOrEqual": "6.18.*"
            },
            {
              "status": "unaffected",
              "version": "7.1.5",
              "versionType": "semver",
              "lessThanOrEqual": "7.1.*"
            },
            {
              "status": "unaffected",
              "version": "7.2",
              "versionType": "original_commit_for_fix",
              "lessThanOrEqual": "*"
            }
          ],
          "programFiles": [
            "drivers/net/ethernet/mellanox/mlx5/core/en.h",
            "drivers/net/ethernet/mellanox/mlx5/core/en/hv_vhca_stats.c",
            "drivers/net/ethernet/mellanox/mlx5/core/en_main.c",
            "drivers/net/ethernet/mellanox/mlx5/core/en_stats.c",
            "drivers/net/ethernet/mellanox/mlx5/core/ipoib/ipoib.c"
          ],
          "defaultStatus": "affected"
        }
      ]
    }
  ],
  "published": "2026-08-15T06:22:07.403",
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/5a799714e8ca0bce9ea40694f49914cf1adbbaa9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/5c7e3755abf663f033de24f917b77685e9543045",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/815515ec68f527ca755cb1e2c1ff9148f6b3ea56",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "vulnStatus": "Received",
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/mlx5e: Fix publication race for priv->channel_stats[]\n\nmlx5e_channel_stats_alloc() publishes a new entry to\npriv->channel_stats[] and then increments priv->stats_nch as a\npublication token, but neither store carries any memory barrier:\n\n\tpriv->channel_stats[ix] = kvzalloc_node(...);\n\tif (!priv->channel_stats[ix])\n\t\treturn -ENOMEM;\n\tpriv->stats_nch++;\n\nConcurrent readers compute the loop bound from priv->stats_nch and\nthen dereference priv->channel_stats[i] using plain accesses, e.g.\n\n\tfor (i = 0; i < priv->stats_nch; i++) {\n\t\tstruct mlx5e_channel_stats *cs = priv->channel_stats[i];\n\t\t... cs->rq.packets ...\n\t}\n\nOn weakly-ordered architectures (ARM, PowerPC, RISC-V) the writes to\nchannel_stats[ix] and stats_nch may become visible to other CPUs out\nof program order. A reader can observe stats_nch == N while still\nseeing channel_stats[N-1] == NULL, leading to a NULL pointer\ndereference in the channel_stats loop.\n\nThis has been observed in production on BlueField-3 DPUs (arm64),\nwhere ovs-vswitchd queries netdev statistics over netlink during NIC\nbringup, racing mlx5e_open_channel() -> mlx5e_channel_stats_alloc()\non another CPU:\n\n  Unable to handle kernel NULL pointer dereference at virtual address 0x840\n  Hardware name: BlueField-3 DPU\n  pc : mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]\n  Call trace:\n   mlx5e_fold_sw_stats64+0x30/0x180 [mlx5_core]\n   dev_get_stats+0x50/0xc0\n   ovs_vport_get_stats+0x38/0xac [openvswitch]\n   ovs_vport_cmd_fill_info+0x194/0x290 [openvswitch]\n   ovs_vport_cmd_get+0xbc/0x10c [openvswitch]\n   genl_family_rcv_msg_doit+0xd0/0x160\n   genl_rcv_msg+0xec/0x1f0\n   netlink_rcv_skb+0x64/0x130\n   genl_rcv+0x40/0x60\n   netlink_unicast+0x2fc/0x370\n   netlink_sendmsg+0x1dc/0x454\n   ...\n   __arm64_sys_sendmsg+0x2c/0x40\n\nAdd mlx5e_stats_nch_write() and mlx5e_stats_nch_read() helpers in en.h\nthat wrap the smp_store_release()/smp_load_acquire() pair on stats_nch.\nThe release/acquire pair establishes the contract:\n\n  stats_nch == N  =>  channel_stats[0..N-1] are visible and non-NULL.\n\nPublish the stats_nch increment via mlx5e_stats_nch_write() in the\nwriter (mlx5e_channel_stats_alloc()), and read stats_nch via\nmlx5e_stats_nch_read() in all readers: mlx5e RX/TX queue stats,\nmlx5e_get_base_stats(), ethtool channels stats, IPoIB stats, the\nsw_stats fold and the HV VHCA stats agent."
    }
  ],
  "lastModified": "2026-08-17T06:18:37.903",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}