cve-2024-53176
Vulnerability from cvelistv5
Published
2024-12-27 13:49
Modified
2025-01-20 06:20
Severity ?
Summary
In the Linux kernel, the following vulnerability has been resolved: smb: During unmount, ensure all cached dir instances drop their dentry The unmount process (cifs_kill_sb() calling close_all_cached_dirs()) can race with various cached directory operations, which ultimately results in dentries not being dropped and these kernel BUGs: BUG: Dentry ffff88814f37e358{i=1000000000080,n=/} still in use (2) [unmount of cifs cifs] VFS: Busy inodes after unmount of cifs (cifs) ------------[ cut here ]------------ kernel BUG at fs/super.c:661! This happens when a cfid is in the process of being cleaned up when, and has been removed from the cfids->entries list, including: - Receiving a lease break from the server - Server reconnection triggers invalidate_all_cached_dirs(), which removes all the cfids from the list - The laundromat thread decides to expire an old cfid. To solve these problems, dropping the dentry is done in queued work done in a newly-added cfid_put_wq workqueue, and close_all_cached_dirs() flushes that workqueue after it drops all the dentries of which it's aware. This is a global workqueue (rather than scoped to a mount), but the queued work is minimal. The final cleanup work for cleaning up a cfid is performed via work queued in the serverclose_wq workqueue; this is done separate from dropping the dentries so that close_all_cached_dirs() doesn't block on any server operations. Both of these queued works expect to invoked with a cfid reference and a tcon reference to avoid those objects from being freed while the work is ongoing. While we're here, add proper locking to close_all_cached_dirs(), and locking around the freeing of cfid->dentry.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/3fa640d035e5ae526769615c35cb9ed4be6e3662
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/548812afd96982a76a93ba76c0582ea670c40d9e
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/73934e535cffbda1490fa97d82690a0f9aa73e94
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/ff4528bbc82d0d90073751f7b49e7b9e9c7e5638
Impacted products
Vendor Product Version
Linux Linux Version: ebe98f1447bbccf8228335c62d86af02a0ed23f7
Version: ebe98f1447bbccf8228335c62d86af02a0ed23f7
Version: ebe98f1447bbccf8228335c62d86af02a0ed23f7
Version: ebe98f1447bbccf8228335c62d86af02a0ed23f7
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   Linux Linux Version: 6.1
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{
   containers: {
      cna: {
         affected: [
            {
               defaultStatus: "unaffected",
               product: "Linux",
               programFiles: [
                  "fs/smb/client/cached_dir.c",
                  "fs/smb/client/cached_dir.h",
                  "fs/smb/client/cifsfs.c",
                  "fs/smb/client/cifsglob.h",
                  "fs/smb/client/inode.c",
                  "fs/smb/client/trace.h",
               ],
               repo: "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               vendor: "Linux",
               versions: [
                  {
                     lessThan: "73934e535cffbda1490fa97d82690a0f9aa73e94",
                     status: "affected",
                     version: "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
                     versionType: "git",
                  },
                  {
                     lessThan: "ff4528bbc82d0d90073751f7b49e7b9e9c7e5638",
                     status: "affected",
                     version: "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
                     versionType: "git",
                  },
                  {
                     lessThan: "548812afd96982a76a93ba76c0582ea670c40d9e",
                     status: "affected",
                     version: "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
                     versionType: "git",
                  },
                  {
                     lessThan: "3fa640d035e5ae526769615c35cb9ed4be6e3662",
                     status: "affected",
                     version: "ebe98f1447bbccf8228335c62d86af02a0ed23f7",
                     versionType: "git",
                  },
               ],
            },
            {
               defaultStatus: "affected",
               product: "Linux",
               programFiles: [
                  "fs/smb/client/cached_dir.c",
                  "fs/smb/client/cached_dir.h",
                  "fs/smb/client/cifsfs.c",
                  "fs/smb/client/cifsglob.h",
                  "fs/smb/client/inode.c",
                  "fs/smb/client/trace.h",
               ],
               repo: "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               vendor: "Linux",
               versions: [
                  {
                     status: "affected",
                     version: "6.1",
                  },
                  {
                     lessThan: "6.1",
                     status: "unaffected",
                     version: "0",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "6.6.*",
                     status: "unaffected",
                     version: "6.6.64",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "6.11.*",
                     status: "unaffected",
                     version: "6.11.11",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "6.12.*",
                     status: "unaffected",
                     version: "6.12.2",
                     versionType: "semver",
                  },
                  {
                     lessThanOrEqual: "*",
                     status: "unaffected",
                     version: "6.13",
                     versionType: "original_commit_for_fix",
                  },
               ],
            },
         ],
         descriptions: [
            {
               lang: "en",
               value: "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: During unmount, ensure all cached dir instances drop their dentry\n\nThe unmount process (cifs_kill_sb() calling close_all_cached_dirs()) can\nrace with various cached directory operations, which ultimately results\nin dentries not being dropped and these kernel BUGs:\n\nBUG: Dentry ffff88814f37e358{i=1000000000080,n=/}  still in use (2) [unmount of cifs cifs]\nVFS: Busy inodes after unmount of cifs (cifs)\n------------[ cut here ]------------\nkernel BUG at fs/super.c:661!\n\nThis happens when a cfid is in the process of being cleaned up when, and\nhas been removed from the cfids->entries list, including:\n\n- Receiving a lease break from the server\n- Server reconnection triggers invalidate_all_cached_dirs(), which\n  removes all the cfids from the list\n- The laundromat thread decides to expire an old cfid.\n\nTo solve these problems, dropping the dentry is done in queued work done\nin a newly-added cfid_put_wq workqueue, and close_all_cached_dirs()\nflushes that workqueue after it drops all the dentries of which it's\naware. This is a global workqueue (rather than scoped to a mount), but\nthe queued work is minimal.\n\nThe final cleanup work for cleaning up a cfid is performed via work\nqueued in the serverclose_wq workqueue; this is done separate from\ndropping the dentries so that close_all_cached_dirs() doesn't block on\nany server operations.\n\nBoth of these queued works expect to invoked with a cfid reference and\na tcon reference to avoid those objects from being freed while the work\nis ongoing.\n\nWhile we're here, add proper locking to close_all_cached_dirs(), and\nlocking around the freeing of cfid->dentry.",
            },
         ],
         providerMetadata: {
            dateUpdated: "2025-01-20T06:20:38.881Z",
            orgId: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
            shortName: "Linux",
         },
         references: [
            {
               url: "https://git.kernel.org/stable/c/73934e535cffbda1490fa97d82690a0f9aa73e94",
            },
            {
               url: "https://git.kernel.org/stable/c/ff4528bbc82d0d90073751f7b49e7b9e9c7e5638",
            },
            {
               url: "https://git.kernel.org/stable/c/548812afd96982a76a93ba76c0582ea670c40d9e",
            },
            {
               url: "https://git.kernel.org/stable/c/3fa640d035e5ae526769615c35cb9ed4be6e3662",
            },
         ],
         title: "smb: During unmount, ensure all cached dir instances drop their dentry",
         x_generator: {
            engine: "bippy-5f407fcff5a0",
         },
      },
   },
   cveMetadata: {
      assignerOrgId: "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      assignerShortName: "Linux",
      cveId: "CVE-2024-53176",
      datePublished: "2024-12-27T13:49:20.518Z",
      dateReserved: "2024-11-19T17:17:25.007Z",
      dateUpdated: "2025-01-20T06:20:38.881Z",
      state: "PUBLISHED",
   },
   dataType: "CVE_RECORD",
   dataVersion: "5.1",
   "vulnerability-lookup:meta": {
      nvd: "{\"cve\":{\"id\":\"CVE-2024-53176\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2024-12-27T14:15:24.947\",\"lastModified\":\"2024-12-27T14:15:24.947\",\"vulnStatus\":\"Received\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nsmb: During unmount, ensure all cached dir instances drop their dentry\\n\\nThe unmount process (cifs_kill_sb() calling close_all_cached_dirs()) can\\nrace with various cached directory operations, which ultimately results\\nin dentries not being dropped and these kernel BUGs:\\n\\nBUG: Dentry ffff88814f37e358{i=1000000000080,n=/}  still in use (2) [unmount of cifs cifs]\\nVFS: Busy inodes after unmount of cifs (cifs)\\n------------[ cut here ]------------\\nkernel BUG at fs/super.c:661!\\n\\nThis happens when a cfid is in the process of being cleaned up when, and\\nhas been removed from the cfids->entries list, including:\\n\\n- Receiving a lease break from the server\\n- Server reconnection triggers invalidate_all_cached_dirs(), which\\n  removes all the cfids from the list\\n- The laundromat thread decides to expire an old cfid.\\n\\nTo solve these problems, dropping the dentry is done in queued work done\\nin a newly-added cfid_put_wq workqueue, and close_all_cached_dirs()\\nflushes that workqueue after it drops all the dentries of which it's\\naware. This is a global workqueue (rather than scoped to a mount), but\\nthe queued work is minimal.\\n\\nThe final cleanup work for cleaning up a cfid is performed via work\\nqueued in the serverclose_wq workqueue; this is done separate from\\ndropping the dentries so that close_all_cached_dirs() doesn't block on\\nany server operations.\\n\\nBoth of these queued works expect to invoked with a cfid reference and\\na tcon reference to avoid those objects from being freed while the work\\nis ongoing.\\n\\nWhile we're here, add proper locking to close_all_cached_dirs(), and\\nlocking around the freeing of cfid->dentry.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/3fa640d035e5ae526769615c35cb9ed4be6e3662\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/548812afd96982a76a93ba76c0582ea670c40d9e\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/73934e535cffbda1490fa97d82690a0f9aa73e94\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ff4528bbc82d0d90073751f7b49e7b9e9c7e5638\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
   },
}


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