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CVE-2026-45894— iommu/vt-d: Clear Present bit before tearing down PASID entry

CVSS 7.8 · High EPSS 0.01% · P2

Affected Version Matrix 10

VendorProductVersion RangeStatus
LinuxLinux0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15< a84d30e8d2bacd21782a6481158b7c9c552f4868affected
0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15< 821807c167b7b48a41b95b6607c6b9f97600f7d9affected
0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15< 949d71666e9dd19f21e7b4b53a88cd2c5b902858affected
0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15< 75ed00055c059dedc47b5daaaa2f8a7a019138ffaffected
5.0affected
< 5.0unaffected
6.12.75≤ 6.12.*unaffected
6.18.14≤ 6.18.*unaffected
… +2 more rows
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I. Basic Information for CVE-2026-45894

Vulnerability Information
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Vulnerability Title
iommu/vt-d: Clear Present bit before tearing down PASID entry
Source: NVD (National Vulnerability Database)
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present bit before tearing down PASID entry The Intel VT-d Scalable Mode PASID table entry consists of 512 bits (64 bytes). When tearing down an entry, the current implementation zeros the entire 64-byte structure immediately using multiple 64-bit writes. Since the IOMMU hardware may fetch these 64 bytes using multiple internal transactions (e.g., four 128-bit bursts), updating or zeroing the entire entry while it is active (P=1) risks a "torn" read. If a hardware fetch occurs simultaneously with the CPU zeroing the entry, the hardware could observe an inconsistent state, leading to unpredictable behavior or spurious faults. Follow the "Guidance to Software for Invalidations" in the VT-d spec (Section 6.5.3.3) by implementing the recommended ownership handshake: 1. Clear only the 'Present' (P) bit of the PASID entry. 2. Use a dma_wmb() to ensure the cleared bit is visible to hardware before proceeding. 3. Execute the required invalidation sequence (PASID cache, IOTLB, and Device-TLB flush) to ensure the hardware has released all cached references. 4. Only after the flushes are complete, zero out the remaining fields of the PASID entry. Also, add a dma_wmb() in pasid_set_present() to ensure that all other fields of the PASID entry are visible to the hardware before the Present bit is set.
Source: NVD (National Vulnerability Database)
CVSS Information
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H
Source: NVD (National Vulnerability Database)
Vulnerability Type
N/A
Source: NVD (National Vulnerability Database)
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会的开源操作系统Linux所使用的内核。 Linux kernel存在安全漏洞，该漏洞源于Intel VT-d驱动在清除PASID表项时未先清除Present位，可能导致硬件读取不一致状态。
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

VendorProductAffected VersionsCPESubscribe
LinuxLinux 0bbeb01a4fafbf8422e5c8882d461d6ac4f71e15 ~ a84d30e8d2bacd21782a6481158b7c9c552f4868 -
LinuxLinux 5.0 -

II. Public POCs for CVE-2026-45894

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III. Intelligence Information for CVE-2026-45894

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Patches & Fixes for CVE-2026-45894 (4)

Same Patch Batch · Linux · 2026-05-27 · 276 CVEs total

CVE-2026-458989.8 CRITICALRDMA/iwcm: Fix workqueue list corruption by removing work_list
CVE-2026-459889.8 CRITICALrxrpc: Fix re-decryption of RESPONSE packets
CVE-2026-459729.8 CRITICALsmb: client: fix potential UAF and double free in smb2_open_file()
CVE-2026-460399.8 CRITICALrxgk: Fix potential integer overflow in length check
CVE-2026-460439.1 CRITICALRDMA/rxe: Validate pad and ICRC before payload_size() in rxe_rcv
CVE-2026-459458.8 HIGHiommu/vt-d: Fix race condition during PASID entry replacement
CVE-2026-460568.8 HIGHBluetooth: hci_event: fix potential UAF in SSP passkey handlers
CVE-2026-458438.2 HIGHslip: bound decode() reads against the compressed packet length
CVE-2026-460378.2 HIGHipv4: icmp: validate reply type before using icmp_pointers
CVE-2026-460998.1 HIGHnet: ipv6: fix NOREF dst use in seg6 and rpl lwtunnels
CVE-2026-460108.1 HIGHrxrpc: Fix error handling in rxgk_extract_token()
CVE-2026-460767.9 HIGHKVM: nSVM: Raise #UD if unhandled VMMCALL isn't intercepted by L1
CVE-2026-458527.8 HIGHRDMA/rxe: Fix double free in rxe_srq_from_init
CVE-2026-458627.8 HIGHiommu/vt-d: Flush cache for PASID table before using it
CVE-2026-460067.8 HIGHdrm/nouveau: fix u32 overflow in pushbuf reloc bounds check
CVE-2026-460587.8 HIGHmedia: amphion: Fix race between m2m job_abort and device_run
CVE-2026-460117.8 HIGHmedia: mtk-jpeg: fix use-after-free in release path due to uncancelled work
CVE-2026-460657.8 HIGHfbdev: defio: Disconnect deferred I/O from the lifetime of struct fb_info
CVE-2026-460367.8 HIGHvfio/cdx: Serialize VFIO_DEVICE_SET_IRQS with a per-device mutex
CVE-2026-458787.8 HIGHdrm/amdkfd: Fix watch_id bounds checking in debug address watch v2

Showing top 20 of 276 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

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Same vendor: Linux

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