{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2025-21820",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2024-12-29T08:45:45.775Z",
        "datePublished": "2025-02-27T20:04:17.930Z",
        "dateUpdated": "2026-05-11T21:07:09.122Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-05-11T21:07:09.122Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: xilinx_uartps: split sysrq handling\n\nlockdep detects the following circular locking dependency:\n\nCPU 0                      CPU 1\n========================== ============================\ncdns_uart_isr()            printk()\n  uart_port_lock(port)       console_lock()\n\t\t\t     cdns_uart_console_write()\n                               if (!port->sysrq)\n                                 uart_port_lock(port)\n  uart_handle_break()\n    port->sysrq = ...\n  uart_handle_sysrq_char()\n    printk()\n      console_lock()\n\nThe fixed commit attempts to avoid this situation by only taking the\nport lock in cdns_uart_console_write if port->sysrq unset. However, if\n(as shown above) cdns_uart_console_write runs before port->sysrq is set,\nthen it will try to take the port lock anyway. This may result in a\ndeadlock.\n\nFix this by splitting sysrq handling into two parts. We use the prepare\nhelper under the port lock and defer handling until we release the lock."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/tty/serial/xilinx_uartps.c"
                    ],
                    "versions": [
                        {
                            "version": "74ea66d4ca061a3cd4c0e924e51b60e924644852",
                            "lessThan": "e22a97700901ba5e8bf8db68056a0d50f9440cae",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "74ea66d4ca061a3cd4c0e924e51b60e924644852",
                            "lessThan": "de5bd24197bd9ee37ec1e379a3d882bbd15c5065",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "74ea66d4ca061a3cd4c0e924e51b60e924644852",
                            "lessThan": "8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "74ea66d4ca061a3cd4c0e924e51b60e924644852",
                            "lessThan": "9b88a7c4584ba67267a051069b8abe44fc9595b2",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "74ea66d4ca061a3cd4c0e924e51b60e924644852",
                            "lessThan": "4410dba9807a17a93f649a9f5870ceaf30a675a3",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "74ea66d4ca061a3cd4c0e924e51b60e924644852",
                            "lessThan": "b06f388994500297bb91be60ffaf6825ecfd2afe",
                            "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/tty/serial/xilinx_uartps.c"
                    ],
                    "versions": [
                        {
                            "version": "4.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "4.6",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.179",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.1.129",
                            "lessThanOrEqual": "6.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.78",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.14",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.13.3",
                            "lessThanOrEqual": "6.13.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.14",
                            "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": "5.15.179"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.1.129"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.6.78"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.12.14"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.13.3"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "4.6",
                                    "versionEndExcluding": "6.14"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/e22a97700901ba5e8bf8db68056a0d50f9440cae"
                },
                {
                    "url": "https://git.kernel.org/stable/c/de5bd24197bd9ee37ec1e379a3d882bbd15c5065"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8ea0e7b3d7b8f2f0fc9db491ff22a0abe120801c"
                },
                {
                    "url": "https://git.kernel.org/stable/c/9b88a7c4584ba67267a051069b8abe44fc9595b2"
                },
                {
                    "url": "https://git.kernel.org/stable/c/4410dba9807a17a93f649a9f5870ceaf30a675a3"
                },
                {
                    "url": "https://git.kernel.org/stable/c/b06f388994500297bb91be60ffaf6825ecfd2afe"
                }
            ],
            "title": "tty: xilinx_uartps: split sysrq handling",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        },
        "adp": [
            {
                "title": "CVE Program Container",
                "references": [
                    {
                        "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html"
                    }
                ],
                "providerMetadata": {
                    "orgId": "af854a3a-2127-422b-91ae-364da2661108",
                    "shortName": "CVE",
                    "dateUpdated": "2025-11-03T20:59:53.209Z"
                }
            }
        ]
    }
}