{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvfs: fix race between evice_inodes() and find_inode()&iput()\n\nHi, all\n\nRecently I noticed a bug[1] in btrfs, after digged it into\nand I believe it'a race in vfs.\n\nLet's assume there's a inode (ie ino 261) with i_count 1 is\ncalled by iput(), and there's a concurrent thread calling\ngeneric_shutdown_super().\n\ncpu0:                              cpu1:\niput() // i_count is 1\n  ->spin_lock(inode)\n  ->dec i_count to 0\n  ->iput_final()                    generic_shutdown_super()\n    ->__inode_add_lru()               ->evict_inodes()\n      // cause some reason[2]           ->if (atomic_read(inode->i_count)) continue;\n      // return before                  // inode 261 passed the above check\n      // list_lru_add_obj()             // and then schedule out\n   ->spin_unlock()\n// note here: the inode 261\n// was still at sb list and hash list,\n// and I_FREEING|I_WILL_FREE was not been set\n\nbtrfs_iget()\n  // after some function calls\n  ->find_inode()\n    // found the above inode 261\n    ->spin_lock(inode)\n   // check I_FREEING|I_WILL_FREE\n   // and passed\n      ->__iget()\n    ->spin_unlock(inode)                // schedule back\n                                        ->spin_lock(inode)\n                                        // check (I_NEW|I_FREEING|I_WILL_FREE) flags,\n                                        // passed and set I_FREEING\niput()                                  ->spin_unlock(inode)\n  ->spin_lock(inode)\t\t\t  ->evict()\n  // dec i_count to 0\n  ->iput_final()\n    ->spin_unlock()\n    ->evict()\n\nNow, we have two threads simultaneously evicting\nthe same inode, which may trigger the BUG(inode->i_state & I_CLEAR)\nstatement both within clear_inode() and iput().\n\nTo fix the bug, recheck the inode->i_count after holding i_lock.\nBecause in the most scenarios, the first check is valid, and\nthe overhead of spin_lock() can be reduced.\n\nIf there is any misunderstanding, please let me know, thanks.\n\n[1]: https://lore.kernel.org/linux-btrfs/000000000000eabe1d0619c48986@google.com/\n[2]: The reason might be 1. SB_ACTIVE was removed or 2. mapping_shrinkable()\nreturn false when I reproduced the bug."
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "fs/inode.c"
               ],
               "versions": [
                  {
                     "version": "63997e98a3be",
                     "lessThan": "47a68c75052a",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "63997e98a3be",
                     "lessThan": "3721a6940329",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "63997e98a3be",
                     "lessThan": "540fb13120c9",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "63997e98a3be",
                     "lessThan": "0eed942bc65d",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "63997e98a3be",
                     "lessThan": "0f8a5b6d0daf",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "63997e98a3be",
                     "lessThan": "6c857fb12b91",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "63997e98a3be",
                     "lessThan": "88b1afbf0f6b",
                     "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/inode.c"
               ],
               "versions": [
                  {
                     "version": "2.6.37",
                     "status": "affected"
                  },
                  {
                     "version": "0",
                     "lessThan": "2.6.37",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.227",
                     "lessThanOrEqual": "5.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.168",
                     "lessThanOrEqual": "5.15.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.1.113",
                     "lessThanOrEqual": "6.1.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.6.54",
                     "lessThanOrEqual": "6.6.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.10.13",
                     "lessThanOrEqual": "6.10.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.11.2",
                     "lessThanOrEqual": "6.11.*",
                     "status": "unaffected",
                     "versionType": "custom"
                  },
                  {
                     "version": "6.12-rc1",
                     "lessThanOrEqual": "*",
                     "status": "unaffected",
                     "versionType": "original_commit_for_fix"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/47a68c75052a660e4c37de41e321582ec9496195"
            },
            {
               "url": "https://git.kernel.org/stable/c/3721a69403291e2514d13a7c3af50a006ea1153b"
            },
            {
               "url": "https://git.kernel.org/stable/c/540fb13120c9eab3ef203f90c00c8e69f37449d1"
            },
            {
               "url": "https://git.kernel.org/stable/c/0eed942bc65de1f93eca7bda51344290f9c573bb"
            },
            {
               "url": "https://git.kernel.org/stable/c/0f8a5b6d0dafa4f533ac82e98f8b812073a7c9d1"
            },
            {
               "url": "https://git.kernel.org/stable/c/6c857fb12b9137fee574443385d53914356bbe11"
            },
            {
               "url": "https://git.kernel.org/stable/c/88b1afbf0f6b221f6c5bb66cc80cd3b38d696687"
            }
         ],
         "title": "vfs: fix race between evice_inodes() and find_inode()&iput()",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2024-47679",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}