{
   "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: free exchange changeset on failures\n\nFstests runs on my VMs have show several kmemleak reports like the following.\n\n  unreferenced object 0xffff88811ae59080 (size 64):\n    comm \"xfs_io\", pid 12124, jiffies 4294987392 (age 6.368s)\n    hex dump (first 32 bytes):\n      00 c0 1c 00 00 00 00 00 ff cf 1c 00 00 00 00 00  ................\n      90 97 e5 1a 81 88 ff ff 90 97 e5 1a 81 88 ff ff  ................\n    backtrace:\n      [<00000000ac0176d2>] ulist_add_merge+0x60/0x150 [btrfs]\n      [<0000000076e9f312>] set_state_bits+0x86/0xc0 [btrfs]\n      [<0000000014fe73d6>] set_extent_bit+0x270/0x690 [btrfs]\n      [<000000004f675208>] set_record_extent_bits+0x19/0x20 [btrfs]\n      [<00000000b96137b1>] qgroup_reserve_data+0x274/0x310 [btrfs]\n      [<0000000057e9dcbb>] btrfs_check_data_free_space+0x5c/0xa0 [btrfs]\n      [<0000000019c4511d>] btrfs_delalloc_reserve_space+0x1b/0xa0 [btrfs]\n      [<000000006d37e007>] btrfs_dio_iomap_begin+0x415/0x970 [btrfs]\n      [<00000000fb8a74b8>] iomap_iter+0x161/0x1e0\n      [<0000000071dff6ff>] __iomap_dio_rw+0x1df/0x700\n      [<000000002567ba53>] iomap_dio_rw+0x5/0x20\n      [<0000000072e555f8>] btrfs_file_write_iter+0x290/0x530 [btrfs]\n      [<000000005eb3d845>] new_sync_write+0x106/0x180\n      [<000000003fb505bf>] vfs_write+0x24d/0x2f0\n      [<000000009bb57d37>] __x64_sys_pwrite64+0x69/0xa0\n      [<000000003eba3fdf>] do_syscall_64+0x43/0x90\n\nIn case brtfs_qgroup_reserve_data() or btrfs_delalloc_reserve_metadata()\nfail the allocated extent_changeset will not be freed.\n\nSo in btrfs_check_data_free_space() and btrfs_delalloc_reserve_space()\nfree the allocated extent_changeset to get rid of the allocated memory.\n\nThe issue currently only happens in the direct IO write path, but only\nafter 65b3c08606e5 (\"btrfs: fix ENOSPC failure when attempting direct IO\nwrite into NOCOW range\"), and also at defrag_one_locked_target(). Every\nother place is always calling extent_changeset_free() even if its call\nto btrfs_delalloc_reserve_space() or btrfs_check_data_free_space() has\nfailed."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/btrfs/delalloc-space.c"
               ],
               "versions": [
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "ca06c5cb1b6d",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "1da177e4c3f4",
                     "lessThan": "da5e817d9d75",
                     "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/delalloc-space.c"
               ],
               "versions": [
                  {
                     "version": "5.15.8",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.16",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/ca06c5cb1b6dbfe67655b33c02fc394d65824519"
            },
            {
               "url": "https://git.kernel.org/stable/c/da5e817d9d75422eaaa05490d0b9a5e328fc1a51"
            }
         ],
         "title": "btrfs: free exchange changeset on failures",
         "x_generator": {
            "engine": "bippy-a5840b7849dd"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2021-47508",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}