{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2023-52856",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/bridge: lt8912b: Fix crash on bridge detach\n\nThe lt8912b driver, in its bridge detach function, calls\ndrm_connector_unregister() and drm_connector_cleanup().\n\ndrm_connector_unregister() should be called only for connectors\nexplicitly registered with drm_connector_register(), which is not the\ncase in lt8912b.\n\nThe driver's drm_connector_funcs.destroy hook is set to\ndrm_connector_cleanup().\n\nThus the driver should not call either drm_connector_unregister() nor\ndrm_connector_cleanup() in its lt8912_bridge_detach(), as they cause a\ncrash on bridge detach:\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000000\nMem abort info:\n  ESR = 0x0000000096000006\n  EC = 0x25: DABT (current EL), IL = 32 bits\n  SET = 0, FnV = 0\n  EA = 0, S1PTW = 0\n  FSC = 0x06: level 2 translation fault\nData abort info:\n  ISV = 0, ISS = 0x00000006, ISS2 = 0x00000000\n  CM = 0, WnR = 0, TnD = 0, TagAccess = 0\n  GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0\nuser pgtable: 4k pages, 48-bit VAs, pgdp=00000000858f3000\n[0000000000000000] pgd=0800000085918003, p4d=0800000085918003, pud=0800000085431003, pmd=0000000000000000\nInternal error: Oops: 0000000096000006 [#1] PREEMPT SMP\nModules linked in: tidss(-) display_connector lontium_lt8912b tc358768 panel_lvds panel_simple drm_dma_helper drm_kms_helper drm drm_panel_orientation_quirks\nCPU: 3 PID: 462 Comm: rmmod Tainted: G        W          6.5.0-rc2+ #2\nHardware name: Toradex Verdin AM62 on Verdin Development Board (DT)\npstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)\npc : drm_connector_cleanup+0x78/0x2d4 [drm]\nlr : lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b]\nsp : ffff800082ed3a90\nx29: ffff800082ed3a90 x28: ffff0000040c1940 x27: 0000000000000000\nx26: 0000000000000000 x25: dead000000000122 x24: dead000000000122\nx23: dead000000000100 x22: ffff000003fb6388 x21: 0000000000000000\nx20: 0000000000000000 x19: ffff000003fb6260 x18: fffffffffffe56e8\nx17: 0000000000000000 x16: 0010000000000000 x15: 0000000000000038\nx14: 0000000000000000 x13: ffff800081914b48 x12: 000000000000040e\nx11: 000000000000015a x10: ffff80008196ebb8 x9 : ffff800081914b48\nx8 : 00000000ffffefff x7 : ffff0000040c1940 x6 : ffff80007aa649d0\nx5 : 0000000000000000 x4 : 0000000000000001 x3 : ffff80008159e008\nx2 : 0000000000000000 x1 : 0000000000000000 x0 : 0000000000000000\nCall trace:\n drm_connector_cleanup+0x78/0x2d4 [drm]\n lt8912_bridge_detach+0x54/0x6c [lontium_lt8912b]\n drm_bridge_detach+0x44/0x84 [drm]\n drm_encoder_cleanup+0x40/0xb8 [drm]\n drmm_encoder_alloc_release+0x1c/0x30 [drm]\n drm_managed_release+0xac/0x148 [drm]\n drm_dev_put.part.0+0x88/0xb8 [drm]\n devm_drm_dev_init_release+0x14/0x24 [drm]\n devm_action_release+0x14/0x20\n release_nodes+0x5c/0x90\n devres_release_all+0x8c/0xe0\n device_unbind_cleanup+0x18/0x68\n device_release_driver_internal+0x208/0x23c\n driver_detach+0x4c/0x94\n bus_remove_driver+0x70/0xf4\n driver_unregister+0x30/0x60\n platform_driver_unregister+0x14/0x20\n tidss_platform_driver_exit+0x18/0xb2c [tidss]\n __arm64_sys_delete_module+0x1a0/0x2b4\n invoke_syscall+0x48/0x110\n el0_svc_common.constprop.0+0x60/0x10c\n do_el0_svc_compat+0x1c/0x40\n el0_svc_compat+0x40/0xac\n el0t_32_sync_handler+0xb0/0x138\n el0t_32_sync+0x194/0x198\nCode: 9104a276 f2fbd5b7 aa0203e1 91008af8 (f85c0420)"
            }
        ]
    },
    "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": "30e2ae943c26",
                                            "version_value": "42071feab712"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "5.13",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "5.13",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "5.15.139",
                                                        "lessThanOrEqual": "5.15.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.1.63",
                                                        "lessThanOrEqual": "6.1.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.5.12",
                                                        "lessThanOrEqual": "6.5.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.6.2",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.7",
                                                        "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/42071feab712ba2a139b8928f7e0f8d3a6fc719e",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/42071feab712ba2a139b8928f7e0f8d3a6fc719e"
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                "url": "https://git.kernel.org/stable/c/7bf0cb8f40280a85034990dfe42be8ca8f80f37a",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/7bf0cb8f40280a85034990dfe42be8ca8f80f37a"
            },
            {
                "url": "https://git.kernel.org/stable/c/fcd9895e365474709844eeb31cfe53d912c3596e",
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                "name": "https://git.kernel.org/stable/c/fcd9895e365474709844eeb31cfe53d912c3596e"
            },
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                "url": "https://git.kernel.org/stable/c/b65e3249f3ca96e3c736af889461d80d675feab6",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/b65e3249f3ca96e3c736af889461d80d675feab6"
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            {
                "url": "https://git.kernel.org/stable/c/44283993144a03af9df31934d6c32bbd42d1a347",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/44283993144a03af9df31934d6c32bbd42d1a347"
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