CVE-2026-64586 (GCVE-0-2026-64586)

Vulnerability from cvelistv5 – Published: 2026-08-06 07:06 – Updated: 2026-08-06 07:06
VLAI
Title
wifi: brcmfmac: drain bus_reset work on device removal
Summary
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
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: 4684997d9eea29380000e062755aa6d368d789a3 , < 177a25be1195f8bdc6160ba5f1a5699f7041c985 (git)
Affected: 4684997d9eea29380000e062755aa6d368d789a3 , < 43b25879f004c98defa2776bedc6ca4763c51945 (git)
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Linux Linux Affected: 5.2
Unaffected: 0 , < 5.2 (semver)
Unaffected: 7.1.6 , ≤ 7.1.* (semver)
Unaffected: 7.2-rc5 , ≤ * (original_commit_for_fix)
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "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",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "177a25be1195f8bdc6160ba5f1a5699f7041c985",
              "status": "affected",
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "versionType": "git"
            },
            {
              "lessThan": "43b25879f004c98defa2776bedc6ca4763c51945",
              "status": "affected",
              "version": "4684997d9eea29380000e062755aa6d368d789a3",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "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",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.2"
            },
            {
              "lessThan": "5.2",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.6",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc5",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.6",
                  "versionStartIncluding": "5.2",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc5",
                  "versionStartIncluding": "5.2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "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-\u003ebus_reset, whose callback recovers drvr through container_of()\nand dereferences it.  The removal path frees drvr (brcmf_free -\u003e\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 -\u003e brcmf_detach; SDIO brcmf_sdio_bus_reset -\u003e\nbrcmf_sdiod_remove -\u003e 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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-06T07:06:27.158Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/177a25be1195f8bdc6160ba5f1a5699f7041c985"
        },
        {
          "url": "https://git.kernel.org/stable/c/43b25879f004c98defa2776bedc6ca4763c51945"
        }
      ],
      "title": "wifi: brcmfmac: drain bus_reset work on device removal",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64586",
    "datePublished": "2026-08-06T07:06:27.158Z",
    "dateReserved": "2026-07-19T15:36:31.798Z",
    "dateUpdated": "2026-08-06T07:06:27.158Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2026-64586",
      "date": "2026-08-06",
      "epss": "0.00145",
      "percentile": "0.04201"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-64586\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-08-06T08:16:33.830\",\"lastModified\":\"2026-08-06T08:16:33.830\",\"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-\u003ebus_reset, whose callback recovers drvr through container_of()\\nand dereferences it.  The removal path frees drvr (brcmf_free -\u003e\\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 -\u003e brcmf_detach; SDIO brcmf_sdio_bus_reset -\u003e\\nbrcmf_sdiod_remove -\u003e 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\":\"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\":\"7.1.6\",\"lessThanOrEqual\":\"7.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"7.2-rc5\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{},\"references\":[{\"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\"}]}}"
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
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  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


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