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wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: wifi: mt76: mt7925: ensure tx headroom in usb_sdio_tx_prepare_skb mt7925_usb_sdio_tx_prepare_skb() pushes a TX descriptor and a USB header onto every skb and assumes the headroom for them is already there. That holds for locally generated traffic, where mac80211 reserves hw->extra_tx_headroom, but forwarded frames are sent through ieee80211_8023_xmit(), which does not reserve it. Bridge a wired interface to an mt7925u AP and the first forwarded frame that arrives short panics the kernel: skbuff: skb_under_panic: len:415 put:4 tail:0x19b end:0x640 dev:wlan1 kernel BUG at net/core/skbuff.c:212! Call trace: skb_panic+0x58/0x60 (P) skb_push+0x58/0x60 mt7925_usb_sdio_tx_prepare_skb+0xf8/0x1b8 [mt7925_common] mt76u_tx_queue_skb+0xa0/0x1f8 [mt76_usb] __mt76_tx_queue_skb+0x54/0xe8 [mt76] mt76_txq_schedule.part.0+0x204/0x478 [mt76] mt76_txq_schedule_all+0x50/0x80 [mt76] mt792x_tx_worker+0x68/0x100 [mt792x_lib] __mt76_worker_fn+0x84/0x150 [mt76] Whether a given setup hits it depends on how much headroom the ingress netdev leaves in its rx skbs. Reproduced on a Raspberry Pi 5 bridging onboard ethernet to a Netgear A9000; originally reported on an MT7986 router running OpenWrt. Nick Morrow's testing on a Pi 4 (bcmgenet), which leaves more headroom, helped narrow the trigger to the ingress path. The same bug was fixed on mt7921 by commit 98c4d0abf5c4 ("mt76: mt7921: don't assume adequate headroom for SDIO headers"), but m

Announced Source revision 1
Original source ↗

CVE-2026-80825

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-80825

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "c948b5da6bbec742b433138e3e3f9537a85af2e5",
        "lessThan": "9a72b180f0575e41471e088e09bddc4b73d6dee2",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c948b5da6bbec742b433138e3e3f9537a85af2e5",
        "lessThan": "22edb6786127271aeba7abd30f152977c605c6a3",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c948b5da6bbec742b433138e3e3f9537a85af2e5",
        "lessThan": "8d481f93588932a95f657671d4e1601b90d130cc",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c948b5da6bbec742b433138e3e3f9537a85af2e5",
        "lessThan": "e5e8fc11a7ac578f16079f855b7fffc1649d053c",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "c948b5da6bbec742b433138e3e3f9537a85af2e5",
        "lessThan": "ef3e34874d2332d0f63e72c2c35ce5c93568c125",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "drivers/net/wireless/mediatek/mt76/mt7925/mac.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.7"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.7",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.12.108",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.49",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.1.13",
        "versionType": "semver",
        "lessThanOrEqual": "7.1.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.3",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "drivers/net/wireless/mediatek/mt76/mt7925/mac.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-80825

Source reference: /cveMetadata/cveId

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No explicit severity was provided.

Event
#34841 · Revision 1
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