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CVE-2026-64586— wifi: brcmfmac: drain bus_reset work on device removal

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于brcmfmac驱动在设备移除时未排空bus_reset工作项，可能导致释放后重用。

CVSS 8.8 · High EPSS 0.25% · P16

Possible ATT&CK Techniques 1 AI

T1059 · Command and Scripting Interpreter

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux 4684997d9eea29380000e062755aa6d368d789a3< 9dfb09cb0abbf92a06f93e0715e163aa188a84da affected
4684997d9eea29380000e062755aa6d368d789a3< 4824e3bcc68f8d678b409039d1bb48c7b5ea73dc affected
4684997d9eea29380000e062755aa6d368d789a3< 61127dd20920bf28460a1609aabb0dafa2f54fac affected
4684997d9eea29380000e062755aa6d368d789a3< c268331845ee00dbdbccb000826bb612dff2bee7 affected
4684997d9eea29380000e062755aa6d368d789a3< e3815d1ffbb9be4f1605ddc3b427557893461683 affected
4684997d9eea29380000e062755aa6d368d789a3< 02d378828af8bb74f6c2f4d2bee3c77cf16c861e affected
4684997d9eea29380000e062755aa6d368d789a3< 177a25be1195f8bdc6160ba5f1a5699f7041c985 affected
4684997d9eea29380000e062755aa6d368d789a3< 43b25879f004c98defa2776bedc6ca4763c51945 affected
… +10 more rows
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I. Basic Information for CVE-2026-64586

Vulnerability Information
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Vulnerability Title
wifi: brcmfmac: drain bus_reset work on device removal
Source: CVE Program / CVE List V5
Vulnerability 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.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于brcmfmac驱动在设备移除时未排空bus_reset工作项，可能导致释放后重用。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux 4684997d9eea29380000e062755aa6d368d789a3 ~ 9dfb09cb0abbf92a06f93e0715e163aa188a84da -
Linux Linux 5.2 -

II. Public POCs for CVE-2026-64586

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III. Intelligence Information for CVE-2026-64586

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Patches & Fixes for CVE-2026-64586 (8)

Same Patch Batch · Linux · 2026-08-06 · 22 CVEs total

CVE-2026-64597 9.8 CRITICAL smb: client: fix double-free in SMB2_close() replay
CVE-2026-64598 8.8 HIGH smb/client: Fix error code in smb2_aead_req_alloc()
CVE-2026-64584 7.8 HIGH usb: gadget: f_midi: cancel pending IN work before freeing the midi object
CVE-2026-64585 7.8 HIGH can: esd_usb: kill anchored URBs before freeing netdevs
CVE-2026-64588 7.8 HIGH fuse-uring: fix data races on ring->ready
CVE-2026-64583 7.8 HIGH usb: gadget: udc: bdc: free IRQ and drain func_wake_notify before teardown
CVE-2026-64601 7.8 HIGH ALSA: us144mkii: capture_urb_complete: redundant usb_anchor_urb corrupts anchor list on ea
CVE-2026-64599 7.8 HIGH crypto: amlogic - avoid double cleanup in meson_crypto_probe()
CVE-2026-64587 7.0 HIGH net: ethernet: arc: emac: quiesce interrupts before requesting IRQ
CVE-2026-68480 x86/bugs: Make Safe-RET robust against interrupt injection
CVE-2026-64604 KVM: VMX: Grab vmcs12 on CR8 interception update iff vCPU is in guest mode
CVE-2026-64603 platform/x86: intel-hid: Protect ACPI notify handler against recursion
CVE-2026-64602 iio: adc: spear: Initialize completion before requesting IRQ
CVE-2026-64596 libfs: set SB_I_NOEXEC and SB_I_NODEV by default in init_pseudo()
CVE-2026-64595 HID: hid-lenovo-go: cancel cfg_setup work in hid_go_cfg_remove()
CVE-2026-64593 btrfs: do not trim a device which is not writeable
CVE-2026-64594 usb: gadget: f_fs: initialize reset_work at allocation time
CVE-2026-64592 riscv: mm: Unconditionally sfence.vma for spurious fault
CVE-2026-64591 iommu/vt-d: Avoid WARNING in sva unbind path
CVE-2026-64590 dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning

Showing top 20 of 22 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-64586

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