{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2023-52854",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npadata: Fix refcnt handling in padata_free_shell()\n\nIn a high-load arm64 environment, the pcrypt_aead01 test in LTP can lead\nto system UAF (Use-After-Free) issues. Due to the lengthy analysis of\nthe pcrypt_aead01 function call, I'll describe the problem scenario\nusing a simplified model:\n\nSuppose there's a user of padata named `user_function` that adheres to\nthe padata requirement of calling `padata_free_shell` after `serial()`\nhas been invoked, as demonstrated in the following code:\n\n```c\nstruct request {\n    struct padata_priv padata;\n    struct completion *done;\n};\n\nvoid parallel(struct padata_priv *padata) {\n    do_something();\n}\n\nvoid serial(struct padata_priv *padata) {\n    struct request *request = container_of(padata,\n    \t\t\t\tstruct request,\n\t\t\t\tpadata);\n    complete(request->done);\n}\n\nvoid user_function() {\n    DECLARE_COMPLETION(done)\n    padata->parallel = parallel;\n    padata->serial = serial;\n    padata_do_parallel();\n    wait_for_completion(&done);\n    padata_free_shell();\n}\n```\n\nIn the corresponding padata.c file, there's the following code:\n\n```c\nstatic void padata_serial_worker(struct work_struct *serial_work) {\n    ...\n    cnt = 0;\n\n    while (!list_empty(&local_list)) {\n        ...\n        padata->serial(padata);\n        cnt++;\n    }\n\n    local_bh_enable();\n\n    if (refcount_sub_and_test(cnt, &pd->refcnt))\n        padata_free_pd(pd);\n}\n```\n\nBecause of the high system load and the accumulation of unexecuted\nsoftirq at this moment, `local_bh_enable()` in padata takes longer\nto execute than usual. Subsequently, when accessing `pd->refcnt`,\n`pd` has already been released by `padata_free_shell()`, resulting\nin a UAF issue with `pd->refcnt`.\n\nThe fix is straightforward: add `refcount_dec_and_test` before calling\n`padata_free_pd` in `padata_free_shell`."
            }
        ]
    },
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                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
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    "affects": {
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                    "product": {
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                            {
                                "product_name": "Linux",
                                "version": {
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                                            "version_affected": "<",
                                            "version_name": "07928d9bfc81",
                                            "version_value": "41aad9d69539"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.6",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "5.6",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
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                                                    {
                                                        "version": "5.10.201",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
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                                                        "version": "5.15.139",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
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                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
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                                                        "lessThanOrEqual": "6.5.*",
                                                        "status": "unaffected",
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                                                        "version": "6.6.2",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
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                                                        "version": "6.7",
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                                                        "status": "unaffected",
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                "name": "https://git.kernel.org/stable/c/0dd34a7ad395dbcf6ae60e48e9786050e25b9bc5"
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                "name": "https://git.kernel.org/stable/c/c7c26d0ef5d20f00dbb2ae3befcabbe0efa77275"
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                "name": "https://git.kernel.org/stable/c/1e901bcb8af19416b65f5063a4af7996e5a51d7f"
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