CVE-2026-64586

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: brcmfmac: drain bus_reset work on device removal brcmf_fw_crashed() and the debugfs "reset" entry both schedule drvr->bus_reset, whose callback recovers drvr through container_of() and dereferences it. The removal path frees drvr (brcmf_free -> wiphy_free) without draining the work, so a bus_reset callback pending or running during removal can outlive drvr. Cancellation cannot live in brcmf_detach() or brcmf_free(): the work callback reaches teardown through the bus .reset op (PCIe brcmf_pcie_reset -> brcmf_detach; SDIO brcmf_sdio_bus_reset -> brcmf_sdiod_remove -> brcmf_free), so cancelling there would wait for the running work and deadlock. Add a per-bus mutex (bus_reset_lock) and route all arming through brcmf_bus_schedule_reset(), which under the lock skips when the bus is marked removing. Each bus remove entry calls brcmf_bus_cancel_reset_work(), which under the same lock sets removing and cancels the work. Holding the mutex across cancel_work_sync() makes the set-removing + drain step atomic. Every producer reaches the arming path from process context -- the PCIe firmware-halt notification runs in the threaded IRQ handler (brcmf_pcie_isr_thread) and the SDIO hostmail path runs from the data workqueue -- so the mutex is taken only in sleepable contexts. Where applicable the remove entry first stops the firmware-crash producer: on PCIe mask the mailbox and synchronize_irq; on SDIO unregister the bus interrupt and cancel the data worker, which also reports firmware halts through brcmf_fw_crashed(). The mutex is initialized at bus allocation. The SDIO suspend power-off path frees drvr through the same brcmf_sdiod_remove() and takes the same lock; resume re-allows the work only on a successful re-probe. Also guard brcmf_fw_crashed() against a NULL bus_if/drvr: it can fire before brcmf_attach() wires up drvr, and it dereferences drvr (bphy_err/brcmf_dev_coredump) before reaching the arming gate. The bus_reset work is shared across buses, so the drain is applied to every remove path: PCIe (the .reset op introduced by the Fixes commit), SDIO (arms the same work through brcmf_fw_crashed()), and USB (via the debugfs "reset" entry). cancel_work_sync() drains a running or pending bus_reset work item before removal frees drvr, and patch 1/2 makes the scratch-buffer release safe when reset teardown has already released those DMA buffers. This patch fixes the lifetime of the bus_reset work item itself. It does not attempt to address the separate, pre-existing lifetime of the asynchronous firmware completion started by the PCIe reset path. That callback needs its own lifetime/ownership protocol and is being tracked separately. This issue was found by an in-house static analysis tool.

Severity

HIGH

CVSS score

8.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-06 08:16:33.830000

Last modified

2026-10-19 21:17:48.760000

View original CVE JSON

{
  "id": "CVE-2026-64586",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-06T08:16:33.830",
  "lastModified": "2026-10-19T21:17:48.760",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nwifi: brcmfmac: drain bus_reset work on device removal\n\nbrcmf_fw_crashed() and the debugfs \"reset\" entry both schedule\ndrvr->bus_reset, whose callback recovers drvr through container_of()\nand dereferences it.  The removal path frees drvr (brcmf_free ->\nwiphy_free) without draining the work, so a bus_reset callback pending\nor running during removal can outlive drvr.\n\nCancellation cannot live in brcmf_detach() or brcmf_free(): the work\ncallback reaches teardown through the bus .reset op (PCIe\nbrcmf_pcie_reset -> brcmf_detach; SDIO brcmf_sdio_bus_reset ->\nbrcmf_sdiod_remove -> brcmf_free), so cancelling there would wait for\nthe running work and deadlock.\n\nAdd a per-bus mutex (bus_reset_lock) and route all arming through\nbrcmf_bus_schedule_reset(), which under the lock skips when the bus is\nmarked removing.  Each bus remove entry calls\nbrcmf_bus_cancel_reset_work(), which under the same lock sets removing\nand cancels the work.  Holding the mutex across cancel_work_sync() makes\nthe set-removing + drain step atomic.  Every producer reaches the arming\npath from process context -- the PCIe firmware-halt notification runs in\nthe threaded IRQ handler (brcmf_pcie_isr_thread) and the SDIO hostmail\npath runs from the data workqueue -- so the mutex is taken only in\nsleepable contexts.  Where applicable the remove entry first stops the\nfirmware-crash producer: on PCIe mask the mailbox and synchronize_irq;\non SDIO unregister the bus interrupt and cancel the data worker, which\nalso reports firmware halts through brcmf_fw_crashed().  The mutex is\ninitialized at bus allocation.  The SDIO suspend power-off path frees\ndrvr through the same brcmf_sdiod_remove() and takes the same lock;\nresume re-allows the work only on a successful re-probe.\n\nAlso guard brcmf_fw_crashed() against a NULL bus_if/drvr: it can fire\nbefore brcmf_attach() wires up drvr, and it dereferences drvr\n(bphy_err/brcmf_dev_coredump) before reaching the arming gate.\n\nThe bus_reset work is shared across buses, so the drain is applied to\nevery remove path: PCIe (the .reset op introduced by the Fixes commit),\nSDIO (arms the same work through brcmf_fw_crashed()), and USB (via the\ndebugfs \"reset\" entry).  cancel_work_sync() drains a running or pending\nbus_reset work item before removal frees drvr, and patch 1/2 makes the\nscratch-buffer release safe when reset teardown has already released\nthose DMA buffers.\n\nThis patch fixes the lifetime of the bus_reset work item itself.  It does\nnot attempt to address the separate, pre-existing lifetime of the\nasynchronous firmware completion started by the PCIe reset path.  That\ncallback needs its own lifetime/ownership protocol and is being tracked\nseparately.\n\nThis issue was found by an in-house static analysis tool."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "9dfb09cb0abbf92a06f93e0715e163aa188a84da",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "4824e3bcc68f8d678b409039d1bb48c7b5ea73dc",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "61127dd20920bf28460a1609aabb0dafa2f54fac",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "c268331845ee00dbdbccb000826bb612dff2bee7",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "e3815d1ffbb9be4f1605ddc3b427557893461683",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "02d378828af8bb74f6c2f4d2bee3c77cf16c861e",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "177a25be1195f8bdc6160ba5f1a5699f7041c985",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "lessThan": "43b25879f004c98defa2776bedc6ca4763c51945",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/bcmsdh.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/bus.h",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/pcie.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.c",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/sdio.h",
            "drivers/net/wireless/broadcom/brcm80211/brcmfmac/usb.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "5.2",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "5.2",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.266",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.217",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.184",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.151",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.103",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.44",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "attackVector": "ADJACENT_NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "NONE",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:43:21.576355Z",
          "id": "CVE-2026-64586",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/02d378828af8bb74f6c2f4d2bee3c77cf16c861e",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/177a25be1195f8bdc6160ba5f1a5699f7041c985",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/43b25879f004c98defa2776bedc6ca4763c51945",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/4824e3bcc68f8d678b409039d1bb48c7b5ea73dc",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/61127dd20920bf28460a1609aabb0dafa2f54fac",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/9dfb09cb0abbf92a06f93e0715e163aa188a84da",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/c268331845ee00dbdbccb000826bb612dff2bee7",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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    {
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      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
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}