{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-93168",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-09-17T16:02:15.090Z",
        "datePublished": "2026-09-17T16:11:59.904Z",
        "dateUpdated": "2026-10-21T12:52:07.553Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-10-21T12:52:07.553Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout\n\nCurrently when calling xilinx_dma_poll_timeout with delay_us=0 and a\ncondition that is never fulfilled, the CPU busy-waits for prolonged time\nand the timeout triggers only with a massive delay causing a CPU stall.\n\nThis happens due to a huge underestimation of wall clock time in\npoll_timeout_us_atomic. Commit 7349a69cf312 (\"iopoll: Do not use\ntimekeeping in read_poll_timeout_atomic()\") changed the behavior to no\nlonger use ktime_get at the expense of underestimation of wall clock\ntime which appears to be very large for delay_us=0. Instead of timing\nout after approximately XILINX_DMA_LOOP_COUNT microseconds, the timeout\ntakes XILINX_DMA_LOOP_COUNT * 1000 * (time that the overhead of the for\nloop in poll_timeout_us_atomic takes) which is in the range of several\nminutes for XILINX_DMA_LOOP_COUNT=1000000. Fix this by using a non-zero\nvalue for delay_us. Use delay_us=10 to keep the delay in the hot path of\nstarting DMA transfers minimal but still avoid CPU stalls in case of\nunexpected hardware failures.\n\nOne-off measurement with delay_us=0 causes the cpu to busy wait around 7\nminutes in the timeout case. After applying this patch with delay_us=10\nthe measured timeout was 1053428 microseconds which is roughly\nequivalent to the expected 1000000 microseconds specified in\nXILINX_DMA_LOOP_COUNT.\n\nAdd a constant XILINX_DMA_POLL_DELAY_US for delay_us value."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/dma/xilinx/xilinx_dma.c"
                    ],
                    "versions": [
                        {
                            "version": "9495f2648287029fb5545c34a0fa318426ebe84c",
                            "lessThan": "2ba67aa183a3ce174d534425b67eda84f6e3c896",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9495f2648287029fb5545c34a0fa318426ebe84c",
                            "lessThan": "c30a26d4987a01e619449bf170f584c007e07d75",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9495f2648287029fb5545c34a0fa318426ebe84c",
                            "lessThan": "f786e7b3adbf3bd14964a1cedf9d55b6ad91dcd7",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9495f2648287029fb5545c34a0fa318426ebe84c",
                            "lessThan": "8b5654d317277e6e505c23f8fa7e415237fefc7f",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "9495f2648287029fb5545c34a0fa318426ebe84c",
                            "lessThan": "aa99c4d1d63bbc26a5fc4c667d89b2595743c19d",
                            "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/xilinx/xilinx_dma.c"
                    ],
                    "versions": [
                        {
                            "version": "4.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.6",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.160",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.114",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.57",
                            "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": "4.6",
                                    "versionEndExcluding": "6.6.160"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.12.114"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.18.57"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "7.2.6"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "7.3"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/2ba67aa183a3ce174d534425b67eda84f6e3c896"
                },
                {
                    "url": "https://git.kernel.org/stable/c/c30a26d4987a01e619449bf170f584c007e07d75"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f786e7b3adbf3bd14964a1cedf9d55b6ad91dcd7"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8b5654d317277e6e505c23f8fa7e415237fefc7f"
                },
                {
                    "url": "https://git.kernel.org/stable/c/aa99c4d1d63bbc26a5fc4c667d89b2595743c19d"
                }
            ],
            "title": "dmaengine: xilinx_dma: Fix CPU stall in xilinx_dma_poll_timeout",
            "x_generator": {
                "engine": "bippy-1.2.0"
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        }
    }
}