{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/kmemleak: avoid scanning potential huge holes\n\nWhen using devm_request_free_mem_region() and devm_memremap_pages() to\nadd ZONE_DEVICE memory, if requested free mem region's end pfn were\nhuge(e.g., 0x400000000), the node_end_pfn() will be also huge (see\nmove_pfn_range_to_zone()).  Thus it creates a huge hole between\nnode_start_pfn() and node_end_pfn().\n\nWe found on some AMD APUs, amdkfd requested such a free mem region and\ncreated a huge hole.  In such a case, following code snippet was just\ndoing busy test_bit() looping on the huge hole.\n\n  for (pfn = start_pfn; pfn < end_pfn; pfn++) {\n\tstruct page *page = pfn_to_online_page(pfn);\n\t\tif (!page)\n\t\t\tcontinue;\n\t...\n  }\n\nSo we got a soft lockup:\n\n  watchdog: BUG: soft lockup - CPU#6 stuck for 26s! [bash:1221]\n  CPU: 6 PID: 1221 Comm: bash Not tainted 5.15.0-custom #1\n  RIP: 0010:pfn_to_online_page+0x5/0xd0\n  Call Trace:\n    ? kmemleak_scan+0x16a/0x440\n    kmemleak_write+0x306/0x3a0\n    ? common_file_perm+0x72/0x170\n    full_proxy_write+0x5c/0x90\n    vfs_write+0xb9/0x260\n    ksys_write+0x67/0xe0\n    __x64_sys_write+0x1a/0x20\n    do_syscall_64+0x3b/0xc0\n    entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nI did some tests with the patch.\n\n(1) amdgpu module unloaded\n\nbefore the patch:\n\n  real    0m0.976s\n  user    0m0.000s\n  sys     0m0.968s\n\nafter the patch:\n\n  real    0m0.981s\n  user    0m0.000s\n  sys     0m0.973s\n\n(2) amdgpu module loaded\n\nbefore the patch:\n\n  real    0m35.365s\n  user    0m0.000s\n  sys     0m35.354s\n\nafter the patch:\n\n  real    0m1.049s\n  user    0m0.000s\n  sys     0m1.042s"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "mm/kmemleak.c"
               ],
               "versions": [
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "d3533ee20e9a",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "352715593e81",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "a5389c80992f",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "cebb0aceb21a",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "c10a0f877fe0",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "mm/kmemleak.c"
               ],
               "versions": [
                  {
                     "version": "5.4.178",
                     "lessThanOrEqual": "5.4.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.99",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.22",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.16.8",
                     "lessThanOrEqual": "5.16.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.17",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/d3533ee20e9a0e2e8f60384da7450d43d1c63d1a"
            },
            {
               "url": "https://git.kernel.org/stable/c/352715593e81b917ce1b321e794549815b850134"
            },
            {
               "url": "https://git.kernel.org/stable/c/a5389c80992f0001ee505838fe6a8b20897ce96e"
            },
            {
               "url": "https://git.kernel.org/stable/c/cebb0aceb21ad91429617a40e3a17444fabf1529"
            },
            {
               "url": "https://git.kernel.org/stable/c/c10a0f877fe007021d70f9cada240f42adc2b5db"
            }
         ],
         "title": "mm/kmemleak: avoid scanning potential huge holes",
         "x_generator": {
            "engine": "bippy-7d53e8ef8be4"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2022-48731",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}