ghsa-h6rm-fwmf-3cqc
Vulnerability from github
Published
2025-08-16 12:30
Modified
2025-11-03 18:31
Details

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

wifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev()

There is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For example, the following is possible:

    T0                      T1

zd_mac_tx_to_dev() / len == skb_queue_len(q) / while (len > ZD_MAC_MAX_ACK_WAITERS) {

                  filter_ack()
                    spin_lock_irqsave(&q->lock, flags);
                    /* position == skb_queue_len(q) */
                    for (i=1; i<position; i++)
                          skb = __skb_dequeue(q)

                    if (mac->type == NL80211_IFTYPE_AP)
                      skb = __skb_dequeue(q);
                    spin_unlock_irqrestore(&q->lock, flags);

skb_dequeue() -> NULL

Since there is a small gap between checking skb queue length and skb being unconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL. Then the pointer is passed to zd_mac_tx_status() where it is dereferenced.

In order to avoid potential NULL pointer dereference due to situations like above, check if skb is not NULL before passing it to zd_mac_tx_status().

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Show details on source website

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{
  "affected": [],
  "aliases": [
    "CVE-2025-38513"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-08-16T11:15:44Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: zd1211rw: Fix potential NULL pointer dereference in zd_mac_tx_to_dev()\n\nThere is a potential NULL pointer dereference in zd_mac_tx_to_dev(). For\nexample, the following is possible:\n\n    \tT0\t\t\t    \t\tT1\nzd_mac_tx_to_dev()\n  /* len == skb_queue_len(q) */\n  while (len \u003e ZD_MAC_MAX_ACK_WAITERS) {\n\n\t\t\t\t\t  filter_ack()\n\t\t\t\t\t    spin_lock_irqsave(\u0026q-\u003elock, flags);\n\t\t\t\t\t    /* position == skb_queue_len(q) */\n\t\t\t\t\t    for (i=1; i\u003cposition; i++)\n\t\t\t\t    \t      skb = __skb_dequeue(q)\n\n\t\t\t\t\t    if (mac-\u003etype == NL80211_IFTYPE_AP)\n\t\t\t\t\t      skb = __skb_dequeue(q);\n\t\t\t\t\t    spin_unlock_irqrestore(\u0026q-\u003elock, flags);\n\n    skb_dequeue() -\u003e NULL\n\nSince there is a small gap between checking skb queue length and skb being\nunconditionally dequeued in zd_mac_tx_to_dev(), skb_dequeue() can return NULL.\nThen the pointer is passed to zd_mac_tx_status() where it is dereferenced.\n\nIn order to avoid potential NULL pointer dereference due to situations like\nabove, check if skb is not NULL before passing it to zd_mac_tx_status().\n\nFound by Linux Verification Center (linuxtesting.org) with SVACE.",
  "id": "GHSA-h6rm-fwmf-3cqc",
  "modified": "2025-11-03T18:31:33Z",
  "published": "2025-08-16T12:30:32Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38513"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/014c34dc132015c4f918ada4982e952947ac1047"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5420de65efbeb6503bcf1d43451c9df67ad60298"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/602b4eb2f25668de15de69860ec99caf65b3684d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/74b1ec9f5d627d2bdd5e5b6f3f81c23317657023"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/adf08c96b963c7cd7ec1ee1c0c556228d9bedaae"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b24f65c184540dfb967479320ecf7e8c2e9220dc"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c1958270de947604cc6de05fc96dbba256b49cf0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/fcd9c923b58e86501450b9b442ccc7ce4a8d0fda"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"
    },
    {
      "type": "WEB",
      "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}


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