cvelist/2024/44xxx/CVE-2024-44976.json

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    "data_version": "4.0",
    "data_type": "CVE",
    "data_format": "MITRE",
    "CVE_data_meta": {
        "ID": "CVE-2024-44976",
        "ASSIGNER": "cve@kernel.org",
        "STATE": "PUBLIC"
    },
    "description": {
        "description_data": [
            {
                "lang": "eng",
                "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nata: pata_macio: Fix DMA table overflow\n\nKolbj\u00f8rn and Jon\u00e1\u0161 reported that their 32-bit PowerMacs were crashing\nin pata-macio since commit 09fe2bfa6b83 (\"ata: pata_macio: Fix\nmax_segment_size with PAGE_SIZE == 64K\").\n\nFor example:\n\n  kernel BUG at drivers/ata/pata_macio.c:544!\n  Oops: Exception in kernel mode, sig: 5 [#1]\n  BE PAGE_SIZE=4K MMU=Hash SMP NR_CPUS=2 DEBUG_PAGEALLOC PowerMac\n  ...\n  NIP pata_macio_qc_prep+0xf4/0x190\n  LR  pata_macio_qc_prep+0xfc/0x190\n  Call Trace:\n    0xc1421660 (unreliable)\n    ata_qc_issue+0x14c/0x2d4\n    __ata_scsi_queuecmd+0x200/0x53c\n    ata_scsi_queuecmd+0x50/0xe0\n    scsi_queue_rq+0x788/0xb1c\n    __blk_mq_issue_directly+0x58/0xf4\n    blk_mq_plug_issue_direct+0x8c/0x1b4\n    blk_mq_flush_plug_list.part.0+0x584/0x5e0\n    __blk_flush_plug+0xf8/0x194\n    __submit_bio+0x1b8/0x2e0\n    submit_bio_noacct_nocheck+0x230/0x304\n    btrfs_work_helper+0x200/0x338\n    process_one_work+0x1a8/0x338\n    worker_thread+0x364/0x4c0\n    kthread+0x100/0x104\n    start_kernel_thread+0x10/0x14\n\nThat commit increased max_segment_size to 64KB, with the justification\nthat the SCSI core was already using that size when PAGE_SIZE == 64KB,\nand that there was existing logic to split over-sized requests.\n\nHowever with a sufficiently large request, the splitting logic causes\neach sg to be split into two commands in the DMA table, leading to\noverflow of the DMA table, triggering the BUG_ON().\n\nWith default settings the bug doesn't trigger, because the request size\nis limited by max_sectors_kb == 1280, however max_sectors_kb can be\nincreased, and apparently some distros do that by default using udev\nrules.\n\nFix the bug for 4KB kernels by reverting to the old max_segment_size.\n\nFor 64KB kernels the sg_tablesize needs to be halved, to allow for the\npossibility that each sg will be split into two."
            }
        ]
    },
    "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": "09fe2bfa6b83",
                                            "version_value": "709e4c8f78e1"
                                        },
                                        {
                                            "version_value": "not down converted",
                                            "x_cve_json_5_version_data": {
                                                "versions": [
                                                    {
                                                        "version": "6.10",
                                                        "status": "affected"
                                                    },
                                                    {
                                                        "version": "0",
                                                        "lessThan": "6.10",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.10.7",
                                                        "lessThanOrEqual": "6.10.*",
                                                        "status": "unaffected",
                                                        "versionType": "semver"
                                                    },
                                                    {
                                                        "version": "6.11",
                                                        "lessThanOrEqual": "*",
                                                        "status": "unaffected",
                                                        "versionType": "original_commit_for_fix"
                                                    }
                                                ],
                                                "defaultStatus": "affected"
                                            }
                                        }
                                    ]
                                }
                            }
                        ]
                    }
                }
            ]
        }
    },
    "references": {
        "reference_data": [
            {
                "url": "https://git.kernel.org/stable/c/709e4c8f78e156ab332297bdd87527ec3da4e2d4",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/709e4c8f78e156ab332297bdd87527ec3da4e2d4"
            },
            {
                "url": "https://git.kernel.org/stable/c/822c8020aebcf5804a143b891e34f29873fee5e2",
                "refsource": "MISC",
                "name": "https://git.kernel.org/stable/c/822c8020aebcf5804a143b891e34f29873fee5e2"
            }
        ]
    },
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