{
    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-35795",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndrm/amdgpu: fix deadlock while reading mqd from debugfs\n\nAn errant disk backup on my desktop got into debugfs and triggered the\nfollowing deadlock scenario in the amdgpu debugfs files. The machine\nalso hard-resets immediately after those lines are printed (although I\nwasn't able to reproduce that part when reading by hand):\n\n[ 1318.016074][ T1082] ======================================================\n[ 1318.016607][ T1082] WARNING: possible circular locking dependency detected\n[ 1318.017107][ T1082] 6.8.0-rc7-00015-ge0c8221b72c0 #17 Not tainted\n[ 1318.017598][ T1082] ------------------------------------------------------\n[ 1318.018096][ T1082] tar/1082 is trying to acquire lock:\n[ 1318.018585][ T1082] ffff98c44175d6a0 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x40/0x80\n[ 1318.019084][ T1082]\n[ 1318.019084][ T1082] but task is already holding lock:\n[ 1318.020052][ T1082] ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]\n[ 1318.020607][ T1082]\n[ 1318.020607][ T1082] which lock already depends on the new lock.\n[ 1318.020607][ T1082]\n[ 1318.022081][ T1082]\n[ 1318.022081][ T1082] the existing dependency chain (in reverse order) is:\n[ 1318.023083][ T1082]\n[ 1318.023083][ T1082] -> #2 (reservation_ww_class_mutex){+.+.}-{3:3}:\n[ 1318.024114][ T1082]        __ww_mutex_lock.constprop.0+0xe0/0x12f0\n[ 1318.024639][ T1082]        ww_mutex_lock+0x32/0x90\n[ 1318.025161][ T1082]        dma_resv_lockdep+0x18a/0x330\n[ 1318.025683][ T1082]        do_one_initcall+0x6a/0x350\n[ 1318.026210][ T1082]        kernel_init_freeable+0x1a3/0x310\n[ 1318.026728][ T1082]        kernel_init+0x15/0x1a0\n[ 1318.027242][ T1082]        ret_from_fork+0x2c/0x40\n[ 1318.027759][ T1082]        ret_from_fork_asm+0x11/0x20\n[ 1318.028281][ T1082]\n[ 1318.028281][ T1082] -> #1 (reservation_ww_class_acquire){+.+.}-{0:0}:\n[ 1318.029297][ T1082]        dma_resv_lockdep+0x16c/0x330\n[ 1318.029790][ T1082]        do_one_initcall+0x6a/0x350\n[ 1318.030263][ T1082]        kernel_init_freeable+0x1a3/0x310\n[ 1318.030722][ T1082]        kernel_init+0x15/0x1a0\n[ 1318.031168][ T1082]        ret_from_fork+0x2c/0x40\n[ 1318.031598][ T1082]        ret_from_fork_asm+0x11/0x20\n[ 1318.032011][ T1082]\n[ 1318.032011][ T1082] -> #0 (&mm->mmap_lock){++++}-{3:3}:\n[ 1318.032778][ T1082]        __lock_acquire+0x14bf/0x2680\n[ 1318.033141][ T1082]        lock_acquire+0xcd/0x2c0\n[ 1318.033487][ T1082]        __might_fault+0x58/0x80\n[ 1318.033814][ T1082]        amdgpu_debugfs_mqd_read+0x103/0x250 [amdgpu]\n[ 1318.034181][ T1082]        full_proxy_read+0x55/0x80\n[ 1318.034487][ T1082]        vfs_read+0xa7/0x360\n[ 1318.034788][ T1082]        ksys_read+0x70/0xf0\n[ 1318.035085][ T1082]        do_syscall_64+0x94/0x180\n[ 1318.035375][ T1082]        entry_SYSCALL_64_after_hwframe+0x46/0x4e\n[ 1318.035664][ T1082]\n[ 1318.035664][ T1082] other info that might help us debug this:\n[ 1318.035664][ T1082]\n[ 1318.036487][ T1082] Chain exists of:\n[ 1318.036487][ T1082]   &mm->mmap_lock --> reservation_ww_class_acquire --> reservation_ww_class_mutex\n[ 1318.036487][ T1082]\n[ 1318.037310][ T1082]  Possible unsafe locking scenario:\n[ 1318.037310][ T1082]\n[ 1318.037838][ T1082]        CPU0                    CPU1\n[ 1318.038101][ T1082]        ----                    ----\n[ 1318.038350][ T1082]   lock(reservation_ww_class_mutex);\n[ 1318.038590][ T1082]                                lock(reservation_ww_class_acquire);\n[ 1318.038839][ T1082]                                lock(reservation_ww_class_mutex);\n[ 1318.039083][ T1082]   rlock(&mm->mmap_lock);\n[ 1318.039328][ T1082]\n[ 1318.039328][ T1082]  *** DEADLOCK ***\n[ 1318.039328][ T1082]\n[ 1318.040029][ T1082] 1 lock held by tar/1082:\n[ 1318.040259][ T1082]  #0: ffff98c4c13f55f8 (reservation_ww_class_mutex){+.+.}-{3:3}, at: amdgpu_debugfs_mqd_read+0x6a/0x250 [amdgpu]\n[ 1318.040560][ T1082]\n[ 1318.040560][ T1082] stack backtrace:\n[\n---truncated---"
            }
        ]
    },
    "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": "445d85e3c1df",
                                            "version_value": "197f6d6987c5"
                                        },
                                        {
                                            "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": "6.6.24",
                                                        "lessThanOrEqual": "6.6.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.7.12",
                                                        "lessThanOrEqual": "6.7.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.8.3",
                                                        "lessThanOrEqual": "6.8.*",
                                                        "status": "unaffected",
                                                        "versionType": "custom"
                                                    },
                                                    {
                                                        "version": "6.9",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/197f6d6987c55860f6eea1c93e4f800c59078874",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/197f6d6987c55860f6eea1c93e4f800c59078874"
            },
            {
                "url": "https://git.kernel.org/stable/c/8b03556da6e576c62664b6cd01809e4a09d53b5b",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8b03556da6e576c62664b6cd01809e4a09d53b5b"
            },
            {
                "url": "https://git.kernel.org/stable/c/4687e3c6ee877ee25e57b984eca00be53b9a8db5",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/4687e3c6ee877ee25e57b984eca00be53b9a8db5"
            },
            {
                "url": "https://git.kernel.org/stable/c/8678b1060ae2b75feb60b87e5b75e17374e3c1c5",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/8678b1060ae2b75feb60b87e5b75e17374e3c1c5"
            }
        ]
    },
    "generator": {
        "engine": "bippy-a5840b7849dd"
    }
}