{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix race in read_extent_buffer_pages()\n\nThere are reports from tree-checker that detects corrupted nodes,\nwithout any obvious pattern so possibly an overwrite in memory.\nAfter some debugging it turns out there's a race when reading an extent\nbuffer the uptodate status can be missed.\n\nTo prevent concurrent reads for the same extent buffer,\nread_extent_buffer_pages() performs these checks:\n\n    /* (1) */\n    if (test_bit(EXTENT_BUFFER_UPTODATE, &eb->bflags))\n        return 0;\n\n    /* (2) */\n    if (test_and_set_bit(EXTENT_BUFFER_READING, &eb->bflags))\n        goto done;\n\nAt this point, it seems safe to start the actual read operation. Once\nthat completes, end_bbio_meta_read() does\n\n    /* (3) */\n    set_extent_buffer_uptodate(eb);\n\n    /* (4) */\n    clear_bit(EXTENT_BUFFER_READING, &eb->bflags);\n\nNormally, this is enough to ensure only one read happens, and all other\ncallers wait for it to finish before returning.  Unfortunately, there is\na racey interleaving:\n\n    Thread A | Thread B | Thread C\n    ---------+----------+---------\n       (1)   |          |\n             |    (1)   |\n       (2)   |          |\n       (3)   |          |\n       (4)   |          |\n             |    (2)   |\n             |          |    (1)\n\nWhen this happens, thread B kicks of an unnecessary read. Worse, thread\nC will see UPTODATE set and return immediately, while the read from\nthread B is still in progress.  This race could result in tree-checker\nerrors like this as the extent buffer is concurrently modified:\n\n    BTRFS critical (device dm-0): corrupted node, root=256\n    block=8550954455682405139 owner mismatch, have 11858205567642294356\n    expect [256, 18446744073709551360]\n\nFix it by testing UPTODATE again after setting the READING bit, and if\nit's been set, skip the unnecessary read.\n\n[ minor update of changelog ]"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/btrfs/extent_io.c"
               ],
               "versions": [
                  {
                     "version": "d7172f52e993",
                     "lessThan": "0427c8ef8bbb",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d7172f52e993",
                     "lessThan": "3a25878a3378",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d7172f52e993",
                     "lessThan": "2885d54af2c2",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d7172f52e993",
                     "lessThan": "ef1e68236b91",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "affected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/btrfs/extent_io.c"
               ],
               "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"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/0427c8ef8bbb7f304de42ef51d69c960e165e052"
            },
            {
               "url": "https://git.kernel.org/stable/c/3a25878a3378adce5d846300c9570f15aa7f7a80"
            },
            {
               "url": "https://git.kernel.org/stable/c/2885d54af2c2e1d910e20d5c8045bae40e02fbc1"
            },
            {
               "url": "https://git.kernel.org/stable/c/ef1e68236b9153c27cb7cf29ead0c532870d4215"
            }
         ],
         "title": "btrfs: fix race in read_extent_buffer_pages()",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-35798",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}