{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2023-52564",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"tty: n_gsm: fix UAF in gsm_cleanup_mux\"\n\nThis reverts commit 9b9c8195f3f0d74a826077fc1c01b9ee74907239.\n\nThe commit above is reverted as it did not solve the original issue.\n\ngsm_cleanup_mux() tries to free up the virtual ttys by calling\ngsm_dlci_release() for each available DLCI. There, dlci_put() is called to\ndecrease the reference counter for the DLCI via tty_port_put() which\nfinally calls gsm_dlci_free(). This already clears the pointer which is\nbeing checked in gsm_cleanup_mux() before calling gsm_dlci_release().\nTherefore, it is not necessary to clear this pointer in gsm_cleanup_mux()\nas done in the reverted commit. The commit introduces a null pointer\ndereference:\n <TASK>\n ? __die+0x1f/0x70\n ? page_fault_oops+0x156/0x420\n ? search_exception_tables+0x37/0x50\n ? fixup_exception+0x21/0x310\n ? exc_page_fault+0x69/0x150\n ? asm_exc_page_fault+0x26/0x30\n ? tty_port_put+0x19/0xa0\n gsmtty_cleanup+0x29/0x80 [n_gsm]\n release_one_tty+0x37/0xe0\n process_one_work+0x1e6/0x3e0\n worker_thread+0x4c/0x3d0\n ? __pfx_worker_thread+0x10/0x10\n kthread+0xe1/0x110\n ? __pfx_kthread+0x10/0x10\n ret_from_fork+0x2f/0x50\n ? __pfx_kthread+0x10/0x10\n ret_from_fork_asm+0x1b/0x30\n </TASK>\n\nThe actual issue is that nothing guards dlci_put() from being called\nmultiple times while the tty driver was triggered but did not yet finished\ncalling gsm_dlci_free()."
            }
        ]
    },
    "problemtype": {
        "problemtype_data": [
            {
                "description": [
                    {
                        "lang": "eng",
                        "value": "n/a"
                    }
                ]
            }
        ]
    },
    "affects": {
        "vendor": {
            "vendor_data": [
                {
                    "vendor_name": "Linux",
                    "product": {
                        "product_data": [
                            {
                                "product_name": "Linux",
                                "version": {
                                    "version_data": [
                                        {
                                            "version_affected": "<",
                                            "version_name": "8fc0eabaa73b",
                                            "version_value": "6d5c8862932d"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "5138c228311a",
                                            "version_value": "a48d2bcd23f2"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "9615ca54bc13",
                                            "version_value": "c61d0b87a702"
                                        },
                                        {
                                            "version_affected": "<",
                                            "version_name": "9b9c8195f3f0",
                                            "version_value": "2bff660e0ff3"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.5",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "6.5",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.10.198",
                                                        "lessThanOrEqual": "5.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.15.134",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.1.56",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.5.6",
                                                        "lessThanOrEqual": "6.5.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
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                                                "defaultStatus": "affected"
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    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/6d5c8862932d31a810b6545f7d69ecc124402c6e",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/6d5c8862932d31a810b6545f7d69ecc124402c6e"
            },
            {
                "url": "https://git.kernel.org/stable/c/a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/a48d2bcd23f2c98d575bc2f9b7a3fbd16aeea9eb"
            },
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                "url": "https://git.kernel.org/stable/c/c61d0b87a7028c2c10faffc524d748334c7b9827",
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                "name": "https://git.kernel.org/stable/c/c61d0b87a7028c2c10faffc524d748334c7b9827"
            },
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                "url": "https://git.kernel.org/stable/c/2bff660e0ff349dee84dc4f6f6d10da4497f5b28",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/2bff660e0ff349dee84dc4f6f6d10da4497f5b28"
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            {
                "url": "https://git.kernel.org/stable/c/29346e217b8ab8a52889b88f00b268278d6b7668",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/29346e217b8ab8a52889b88f00b268278d6b7668"
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