{ "data_version": "4.0", "data_type": "CVE", "data_format": "MITRE", "CVE_data_meta": { "ID": "CVE-2024-50022", "ASSIGNER": "cve@kernel.org", "STATE": "PUBLIC" }, "description": { "description_data": [ { "lang": "eng", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ndevice-dax: correct pgoff align in dax_set_mapping()\n\npgoff should be aligned using ALIGN_DOWN() instead of ALIGN(). Otherwise,\nvmf->address not aligned to fault_size will be aligned to the next\nalignment, that can result in memory failure getting the wrong address.\n\nIt's a subtle situation that only can be observed in\npage_mapped_in_vma() after the page is page fault handled by\ndev_dax_huge_fault. Generally, there is little chance to perform\npage_mapped_in_vma in dev-dax's page unless in specific error injection\nto the dax device to trigger an MCE - memory-failure. In that case,\npage_mapped_in_vma() will be triggered to determine which task is\naccessing the failure address and kill that task in the end.\n\n\nWe used self-developed dax device (which is 2M aligned mapping) , to\nperform error injection to random address. It turned out that error\ninjected to non-2M-aligned address was causing endless MCE until panic.\nBecause page_mapped_in_vma() kept resulting wrong address and the task\naccessing the failure address was never killed properly:\n\n\n[ 3783.719419] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3784.049006] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3784.049190] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3784.448042] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3784.448186] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3784.792026] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3784.792179] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3785.162502] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3785.162633] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3785.461116] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3785.461247] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3785.764730] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3785.764859] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3786.042128] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3786.042259] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3786.464293] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3786.464423] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3786.818090] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3786.818217] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n[ 3787.085297] mce: Uncorrected hardware memory error in user-access at \n200c9742380\n[ 3787.085424] Memory failure: 0x200c9742: recovery action for dax page: \nRecovered\n\nIt took us several weeks to pinpoint this problem,\u00a0 but we eventually\nused bpftrace to trace the page fault and mce address and successfully\nidentified the issue.\n\n\nJoao added:\n\n; Likely we never reproduce in production because we always pin\n: device-dax regions in the region align they provide (Qemu does\n: similarly with prealloc in hugetlb/file backed memory). I think this\n: bug requires that we touch *unpinned* device-dax regions unaligned to\n: the device-dax selected alignment (page size i.e. 4K/2M/1G)" } ] }, "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": "b9b5777f09be", "version_value": "9c4198dfdca8" }, { "version_value": "not down converted", "x_cve_json_5_version_data": { "versions": [ { "version": "5.17", "status": "affected" }, { "version": "0", "lessThan": "5.17", "status": "unaffected", "versionType": "custom" }, { "version": "6.1.113", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.6.57", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.11.4", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "custom" }, { "version": "6.12-rc3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ], "defaultStatus": "affected" } } ] } } ] } } ] } }, "references": { "reference_data": [ { "url": "https://git.kernel.org/stable/c/9c4198dfdca818c5ce19c764d90eabd156bbc6da", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/9c4198dfdca818c5ce19c764d90eabd156bbc6da" }, { "url": "https://git.kernel.org/stable/c/b822007e8db341d6f175c645ed79866db501ad86", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/b822007e8db341d6f175c645ed79866db501ad86" }, { "url": "https://git.kernel.org/stable/c/e877427d218159ac29c9326100920d24330c9ee6", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/e877427d218159ac29c9326100920d24330c9ee6" }, { "url": "https://git.kernel.org/stable/c/7fcbd9785d4c17ea533c42f20a9083a83f301fa6", "refsource": "MISC", "name": "https://git.kernel.org/stable/c/7fcbd9785d4c17ea533c42f20a9083a83f301fa6" } ] }, "generator": { "engine": "bippy-c9c4e1df01b2" } }