{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-93042", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-17T15:57:05.657Z", "datePublished": "2026-09-17T16:10:34.911Z", "dateUpdated": "2026-10-19T09:04:37.231Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:04:37.231Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: dw-edma: Terminate all descriptors without callbacks\n\nThe DMA Engine client documentation says in the \"Terminate APIs\" section\nof Documentation/driver-api/dmaengine/client.rst:\n\n\"No callback functions will be called for any incomplete transfers.\"\n\ndw-edma instead calls vchan_cookie_complete() when a deferred STOP reaches\nthe interrupt handler. This schedules a callback for the active descriptor\nand leaves other issued or submitted descriptors queued. A late callback\nafter dmaengine_terminate_sync() can dereference client state that has\nalready been freed, while leftover descriptors may later restart into\nreused buffers or leak.\n\nMove all issued and submitted descriptors to the terminated list whenever\ntermination completes. For a pending STOP, do this from both the DONE and\nABORT paths. Complete their cookies in order without scheduling callbacks.\n\nA STOP can remain pending until the running transfer raises an\ninterrupt. Make device_synchronize() wait for such a pending STOP to\ncomplete before releasing terminated descriptors. Reuse it from\nfree_chan_resources(), then release the remaining virt-dma resources.\nSleep instead of busy-polling while waiting, and warn if the existing\ntimeout expires." } ], "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 - On DesignWare PCIe endpoint SoCs the host starts eDMA via pci_epf_mhi_edma_read()/write() (MHI transfers ≥4K), nvmet_pci_epf_dma_transfer(), or pci_epf_test BAR COMMAND_READ|WRITE with FLAG_USE_DMA, then those clients call dmaengine_terminate_sync() on the local dw-edma channel; the trigger is PCIe-link peer traffic, not a local syscall or a routable protocol.\nAC:L - pci_epf_mhi_edma_read() waits only 1000ms then calls dmaengine_terminate_sync(); a host that issues a ≥4K MHI DMA and stalls it hits that timeout while EDMA_ST_BUSY. Vulnerable dw_edma_device_terminate_all() only stores EDMA_REQ_STOP and returns 0 because device_synchronize was unimplemented, so the host can drop the stall and deliver the DONE/ABORT IRQ itself.\nPR:N - pci_epf_mhi_edma_read()/write() and nvmet_pci_epf_dma_transfer() do not authenticate the PCIe host; MHI TREs, NVMe I/O, or BAR command-register COMMAND_READ/WRITE writes from the upstream port suffice, with no Linux uid, capability, or user-namespace check on the endpoint.\nUI:N - The PCIe host starts the MHI/NVMe/epf-test DMA and forces the client's terminate-on-timeout path itself; no victim mount, file open, or other interactive step is required once the endpoint function is already bound.\nS:U - The late vchan_complete() callback UAF and leftover desc_issued restarts corrupt callback state and DMA buffers inside the same endpoint kernel that hosts dw-edma; that is in-kernel memory corruption, not a KVM/Xen guest escape or an IOMMU policy bypass.\nC:H - dw_edma_done_interrupt()'s EDMA_REQ_STOP path calls vchan_cookie_complete(), so vchan_complete() can invoke pci_epf_mhi_dma_callback() after pci_epf_mhi_edma_read() returned and its DECLARE_COMPLETION_ONSTACK died; leftover issued descriptors can also dw_edma_start_transfer() MEM_TO_DEV from reused kernel pages into host memory.\nI:H - After dma_unmap_single() in the MHI/nvmet timeout path, leftover desc_issued entries stay queued, so a later issue_pending() runs dw_edma_start_transfer() DEV_TO_MEM into those unmapped/reused pages, and the late callback UAF likewise corrupts kernel state, giving a write primitive.\nA:H - The STOP-path vchan_cookie_complete() UAF in vchan_complete() and DMA into buffers already unmapped by pci_epf_mhi_edma_read() or nvmet_pci_epf_dma_transfer() oops or panic the endpoint kernel, as the fix commit describes for a late callback after dmaengine_terminate_sync()." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/dma/dw-edma/dw-edma-core.c" ], "versions": [ { "version": "e63d79d1ffcd2201a2dbff1d7a1184b8f3ec74cf", "lessThan": "65e387b95d3855aa894ac729e1778e5bcb9083cb", "status": "affected", "versionType": "git" }, { "version": "e63d79d1ffcd2201a2dbff1d7a1184b8f3ec74cf", "lessThan": "4793f9099a1cadf4e37f3a03d524af6bce88a0ea", "status": "affected", "versionType": "git" }, { "version": "e63d79d1ffcd2201a2dbff1d7a1184b8f3ec74cf", "lessThan": "be87d86537de7ea6fd025f41033d2faff880973f", "status": "affected", "versionType": "git" }, { "version": "e63d79d1ffcd2201a2dbff1d7a1184b8f3ec74cf", "lessThan": "f3ec6702a1d216be61f692cc0a983d6c8fb5ebf7", "status": "affected", "versionType": "git" }, { "version": "e63d79d1ffcd2201a2dbff1d7a1184b8f3ec74cf", "lessThan": "99109a51efd28c9a661fbfb9469b023c517b31d1", "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/dma/dw-edma/dw-edma-core.c" ], "versions": [ { "version": "5.3", "status": "affected" }, { "version": "0", "lessThan": "5.3", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.157", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.52", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.6", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "5.3", "versionEndExcluding": "6.6.157" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "6.18.52" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "7.2.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.3", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/65e387b95d3855aa894ac729e1778e5bcb9083cb" }, { "url": "https://git.kernel.org/stable/c/4793f9099a1cadf4e37f3a03d524af6bce88a0ea" }, { "url": "https://git.kernel.org/stable/c/be87d86537de7ea6fd025f41033d2faff880973f" }, { "url": "https://git.kernel.org/stable/c/f3ec6702a1d216be61f692cc0a983d6c8fb5ebf7" }, { "url": "https://git.kernel.org/stable/c/99109a51efd28c9a661fbfb9469b023c517b31d1" } ], "title": "dmaengine: dw-edma: Terminate all descriptors without callbacks", "x_generator": { "engine": "bippy-1.2.0" } } } }