{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64586", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.798Z", "datePublished": "2026-08-06T07:06:27.158Z", "dateUpdated": "2026-08-23T12:45:44.685Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:44.685Z" }, "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." } ], "metrics": [ { "cvssV3_1": { "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" }, "scenarios": [ { "lang": "en", "value": "AV:A - bus_reset is armed by brcmf_fw_crashed() when Broadcom fullmac signals FWHALT (PCIe mailbox ISR thread / SDIO hostmail). An adjacent 802.11 attacker can induce that halt with malformed frames; the pending work then races device removal (USB hot-unplug, SDIO suspend power-off) that frees drvr without draining the work.\nAC:L - The attacker repeatedly induces firmware halts to schedule bus_reset and can align removal (USB unplug on shared dongles/kiosks, or SDIO suspend) so the work runs after wiphy_free; both sides are attacker-influenced and freely retryable, so success does not depend on uncontrollable timing.\nPR:N - FWHALT delivery and brcmf_fw_crashed() need no host credentials; concurrent free via USB disconnect or automatic SDIO power-cut suspend likewise requires no account or capability. The debugfs reset path is root-only but is not the highest-severity reachability.\nUI:N - Firmware-halt recovery and device removal/suspend paths run in kernel workqueues and bus callbacks without the victim opening a file, mounting media, or otherwise interacting.\nS:U - The UAF corrupts host-kernel heap (struct brcmf_pub embedded in the wiphy) within the same kernel security authority; it is not a VM escape, IOMMU bypass, or sandbox boundary crossing.\nC:H - Use-after-free of drvr via container_of on the freed bus_reset work_struct lets an attacker reallocate the wiphy/drvr slab and observe attacker-controlled object contents through subsequent driver dereferences, yielding an arbitrary kernel read primitive.\nI:H - The recycled work_struct/drvr is dispatched by the workqueue (func pointer / bus_if ops), enabling heap corruption and control-flow hijack when brcmf_core_bus_reset runs on attacker-shaped memory after brcmf_free/wiphy_free.\nA:H - Even without full exploitation, running bus_reset after wiphy_free dereferences freed drvr/bus_if state and reliably causes kernel oops/panic or driver teardown failure, denying availability of the host." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "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" ], "versions": [ { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "9dfb09cb0abbf92a06f93e0715e163aa188a84da", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "4824e3bcc68f8d678b409039d1bb48c7b5ea73dc", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "61127dd20920bf28460a1609aabb0dafa2f54fac", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "c268331845ee00dbdbccb000826bb612dff2bee7", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "e3815d1ffbb9be4f1605ddc3b427557893461683", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "02d378828af8bb74f6c2f4d2bee3c77cf16c861e", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "177a25be1195f8bdc6160ba5f1a5699f7041c985", "status": "affected", "versionType": "git" }, { "version": "4684997d9eea29380000e062755aa6d368d789a3", "lessThan": "43b25879f004c98defa2776bedc6ca4763c51945", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "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" ], "versions": [ { "version": "5.2", "status": "affected" }, { "version": "0", "lessThan": "5.2", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.266", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.151", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.103", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.44", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "5.10.266" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "5.15.217" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.6.151" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.12.103" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.18.44" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/9dfb09cb0abbf92a06f93e0715e163aa188a84da" }, { "url": "https://git.kernel.org/stable/c/4824e3bcc68f8d678b409039d1bb48c7b5ea73dc" }, { "url": "https://git.kernel.org/stable/c/61127dd20920bf28460a1609aabb0dafa2f54fac" }, { "url": "https://git.kernel.org/stable/c/c268331845ee00dbdbccb000826bb612dff2bee7" }, { "url": "https://git.kernel.org/stable/c/e3815d1ffbb9be4f1605ddc3b427557893461683" }, { "url": "https://git.kernel.org/stable/c/02d378828af8bb74f6c2f4d2bee3c77cf16c861e" }, { "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" } } } }