{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-36892",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/slub: avoid zeroing outside-object freepointer for single free\n\nCommit 284f17ac13fe (\"mm/slub: handle bulk and single object freeing\nseparately\") splits single and bulk object freeing in two functions\nslab_free() and slab_free_bulk() which leads slab_free() to call\nslab_free_hook() directly instead of slab_free_freelist_hook().\n\nIf `init_on_free` is set, slab_free_hook() zeroes the object.\nAfterward, if `slub_debug=F` and `CONFIG_SLAB_FREELIST_HARDENED` are\nset, the do_slab_free() slowpath executes freelist consistency\nchecks and try to decode a zeroed freepointer which leads to a\n\"Freepointer corrupt\" detection in check_object().\n\nDuring bulk free, slab_free_freelist_hook() isn't affected as it always\nsets it objects freepointer using set_freepointer() to maintain its\nreconstructed freelist after `init_on_free`.\n\nFor single free, object's freepointer thus needs to be avoided when\nstored outside the object if `init_on_free` is set. The freepointer left\nas is, check_object() may later detect an invalid pointer value due to\nobjects overflow.\n\nTo reproduce, set `slub_debug=FU init_on_free=1 log_level=7` on the\ncommand line of a kernel build with `CONFIG_SLAB_FREELIST_HARDENED=y`.\n\ndmesg sample log:\n[   10.708715] =============================================================================\n[   10.710323] BUG kmalloc-rnd-05-32 (Tainted: G    B           T ): Freepointer corrupt\n[   10.712695] -----------------------------------------------------------------------------\n[   10.712695]\n[   10.712695] Slab 0xffffd8bdc400d580 objects=32 used=4 fp=0xffff9d9a80356f80 flags=0x200000000000a00(workingset|slab|node=0|zone=2)\n[   10.716698] Object 0xffff9d9a80356600 @offset=1536 fp=0x7ee4f480ce0ecd7c\n[   10.716698]\n[   10.716698] Bytes b4 ffff9d9a803565f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n[   10.720703] Object   ffff9d9a80356600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n[   10.720703] Object   ffff9d9a80356610: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n[   10.724696] Padding  ffff9d9a8035666c: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................\n[   10.724696] Padding  ffff9d9a8035667c: 00 00 00 00                                      ....\n[   10.724696] FIX kmalloc-rnd-05-32: Object at 0xffff9d9a80356600 not freed"
            }
        ]
    },
    "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": "284f17ac13fe",
                                            "version_value": "56900355485f"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.8",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "6.8",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.8.10",
                                                        "lessThanOrEqual": "6.8.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.9",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/56900355485f6e82114b18c812edd57fd7970dcb",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/56900355485f6e82114b18c812edd57fd7970dcb"
            },
            {
                "url": "https://git.kernel.org/stable/c/8f828aa48812ced28aa39cb3cfe55ef2444d03dd",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8f828aa48812ced28aa39cb3cfe55ef2444d03dd"
            }
        ]
    },
    "generator": {
        "engine": "bippy-9e1c9544281a"
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}