{"id":"AZL-51386","summary":"CVE-2024-50022 affecting package kernel for versions less than 6.6.57.1-1","details":"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-\u003eaddress 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,  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)","modified":"2026-04-01T05:17:43.181847Z","published":"2024-10-21T20:15:15Z","upstream":["CVE-2024-50022"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-50022"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.6.57.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-51386.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H"}]}