{"id":"CVE-2026-64586","state":"PUBLISHED","title":"wifi: brcmfmac: drain bus_reset work on device removal","description":"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.","publishedAt":"2026-08-06T07:06:27.158Z","updatedAt":"2026-10-19T20:48:43.327Z","severity":{"score":8.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"9dfb09cb0abbf92a06f93e0715e163aa188a84da","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"4824e3bcc68f8d678b409039d1bb48c7b5ea73dc","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"61127dd20920bf28460a1609aabb0dafa2f54fac","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"c268331845ee00dbdbccb000826bb612dff2bee7","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"e3815d1ffbb9be4f1605ddc3b427557893461683","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"02d378828af8bb74f6c2f4d2bee3c77cf16c861e","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"177a25be1195f8bdc6160ba5f1a5699f7041c985","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"43b25879f004c98defa2776bedc6ca4763c51945","versionType":"git"}],"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"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.2","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.184","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"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"]}],"references":["https://git.kernel.org/stable/c/9dfb09cb0abbf92a06f93e0715e163aa188a84da","https://git.kernel.org/stable/c/4824e3bcc68f8d678b409039d1bb48c7b5ea73dc","https://git.kernel.org/stable/c/61127dd20920bf28460a1609aabb0dafa2f54fac","https://git.kernel.org/stable/c/c268331845ee00dbdbccb000826bb612dff2bee7","https://git.kernel.org/stable/c/e3815d1ffbb9be4f1605ddc3b427557893461683","https://git.kernel.org/stable/c/02d378828af8bb74f6c2f4d2bee3c77cf16c861e","https://git.kernel.org/stable/c/177a25be1195f8bdc6160ba5f1a5699f7041c985","https://git.kernel.org/stable/c/43b25879f004c98defa2776bedc6ca4763c51945"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64586.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64586","state":"PUBLISHED","datePublished":"2026-08-06T07:06:27.158Z","dateUpdated":"2026-10-19T20:48:43.327Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T15:36:31.798Z"},"containers":{"cna":{"title":"wifi: brcmfmac: drain bus_reset work on device removal","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":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"9dfb09cb0abbf92a06f93e0715e163aa188a84da","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"4824e3bcc68f8d678b409039d1bb48c7b5ea73dc","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"61127dd20920bf28460a1609aabb0dafa2f54fac","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"c268331845ee00dbdbccb000826bb612dff2bee7","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"e3815d1ffbb9be4f1605ddc3b427557893461683","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"02d378828af8bb74f6c2f4d2bee3c77cf16c861e","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"177a25be1195f8bdc6160ba5f1a5699f7041c985","versionType":"git"},{"version":"4684997d9eea29380000e062755aa6d368d789a3","status":"affected","lessThan":"43b25879f004c98defa2776bedc6ca4763c51945","versionType":"git"}],"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"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.2","versionType":"semver"},{"version":"5.10.266","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.217","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.184","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.151","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.103","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.44","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"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"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-23T12:45:44.685Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-64586","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:43:21.576355Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:48:43.327Z"}}]}}}