CVE-2026-98827 (GCVE-0-2026-98827)
Vulnerability from cvelistv5
Published
2026-10-18 15:49
Modified
2026-10-19 09:26
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE __hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a single tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch by record count but never by cumulative byte length. With large frames (MTU 2304), 20 aggregated frames of 2292 bytes each exceed the allocation (20 * 2296 = 45920 bytes), so the memcpy() in the loop writes up to 13152 bytes past tx_buf->buf before usb_submit_urb(). Peek the queue head and stop before copying any record that would cross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover skbs remain queued and are drained on the next URB completion. The byte bound changes the loop's exit semantics: it can now exit before i == tx_skb_cnt - 1. Stock only finalized tx_buf->len on that last index (len += offset), so an early break would submit a URB holding only the last record's length while every dequeued skb is freed on completion, silently dropping frames. Make tx_buf->len a running total and advance tx_buf->offset per record instead; the stride round_up(nskb->len + 4, 4) is identical to the stock stride when the loop runs to completion. Tested on hardware with an MTU 2304 flood: the loop stops at record 15 (len = 32144, offset = 32144, within 32768), no oversized URB is submitted, and MTU 1500 pings pass 20/20.
References
Impacted products
Vendor Product Version
Linux Linux Version: fb9987d0f748c983bb795a86f47522313f701a08
Version: fb9987d0f748c983bb795a86f47522313f701a08
Version: fb9987d0f748c983bb795a86f47522313f701a08
Version: fb9987d0f748c983bb795a86f47522313f701a08
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wireless/ath/ath9k/hif_usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c18882768a0fe253c70986c5fe66d9241570fbc4",
              "status": "affected",
              "version": "fb9987d0f748c983bb795a86f47522313f701a08",
              "versionType": "git"
            },
            {
              "lessThan": "345ce265cf604e84b5b560c21beaf4c6f269ab14",
              "status": "affected",
              "version": "fb9987d0f748c983bb795a86f47522313f701a08",
              "versionType": "git"
            },
            {
              "lessThan": "e73a619f91b6cfec47bc1a94aea28df6849e5be3",
              "status": "affected",
              "version": "fb9987d0f748c983bb795a86f47522313f701a08",
              "versionType": "git"
            },
            {
              "lessThan": "aeaca27c1db3106967ffbb2b517d98c835f6d500",
              "status": "affected",
              "version": "fb9987d0f748c983bb795a86f47522313f701a08",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/wireless/ath/ath9k/hif_usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.35"
            },
            {
              "lessThan": "2.6.35",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.113",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.56",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.10",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.113",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.56",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2.10",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3",
                  "versionStartIncluding": "2.6.35",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE\n\n__hif_usb_tx() dequeues up to MAX_TX_AGGR_NUM (20) frames into a\nsingle tx_buf of MAX_TX_BUF_SIZE (32768) bytes, limiting the batch\nby record count but never by cumulative byte length.\n\nWith large frames (MTU 2304), 20 aggregated frames of 2292 bytes\neach exceed the allocation (20 * 2296 = 45920 bytes), so the\nmemcpy() in the loop writes up to 13152 bytes past tx_buf-\u003ebuf\nbefore usb_submit_urb().\n\nPeek the queue head and stop before copying any record that would\ncross MAX_TX_BUF_SIZE, then dispatch the current batch. Leftover\nskbs remain queued and are drained on the next URB completion.\n\nThe byte bound changes the loop\u0027s exit semantics: it can now exit\nbefore i == tx_skb_cnt - 1. Stock only finalized tx_buf-\u003elen on\nthat last index (len += offset), so an early break would submit a\nURB holding only the last record\u0027s length while every dequeued skb\nis freed on completion, silently dropping frames. Make tx_buf-\u003elen\na running total and advance tx_buf-\u003eoffset per record instead; the\nstride round_up(nskb-\u003elen + 4, 4) is identical to the stock stride\nwhen the loop runs to completion.\n\nTested on hardware with an MTU 2304 flood: the loop stops at\nrecord 15 (len = 32144, offset = 32144, within 32768), no\noversized URB is submitted, and MTU 1500 pings pass 20/20."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:26:19.987Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/c18882768a0fe253c70986c5fe66d9241570fbc4"
        },
        {
          "url": "https://git.kernel.org/stable/c/345ce265cf604e84b5b560c21beaf4c6f269ab14"
        },
        {
          "url": "https://git.kernel.org/stable/c/e73a619f91b6cfec47bc1a94aea28df6849e5be3"
        },
        {
          "url": "https://git.kernel.org/stable/c/aeaca27c1db3106967ffbb2b517d98c835f6d500"
        }
      ],
      "title": "wifi: ath9k_htc: bound TX aggregation to MAX_TX_BUF_SIZE",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-98827",
    "datePublished": "2026-10-18T15:49:20.872Z",
    "dateReserved": "2026-09-25T10:25:14.372Z",
    "dateUpdated": "2026-10-19T09:26:19.987Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.