{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-53178", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-11-19T17:17:25.008Z", "datePublished": "2024-12-27T13:49:22.085Z", "dateUpdated": "2026-08-05T11:44:25.194Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:44:25.194Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsmb: Don't leak cfid when reconnect races with open_cached_dir\n\nopen_cached_dir() may either race with the tcon reconnection even before\ncompound_send_recv() or directly trigger a reconnection via\nSMB2_open_init() or SMB_query_info_init().\n\nThe reconnection process invokes invalidate_all_cached_dirs() via\ncifs_mark_open_files_invalid(), which removes all cfids from the\ncfids->entries list but doesn't drop a ref if has_lease isn't true. This\nresults in the currently-being-constructed cfid not being on the list,\nbut still having a refcount of 2. It leaks if returned from\nopen_cached_dir().\n\nFix this by setting cfid->has_lease when the ref is actually taken; the\ncfid will not be used by other threads until it has a valid time.\n\nAddresses these kmemleaks:\n\nunreferenced object 0xffff8881090c4000 (size 1024):\n comm \"bash\", pid 1860, jiffies 4295126592\n hex dump (first 32 bytes):\n 00 01 00 00 00 00 ad de 22 01 00 00 00 00 ad de ........\".......\n 00 ca 45 22 81 88 ff ff f8 dc 4f 04 81 88 ff ff ..E\"......O.....\n backtrace (crc 6f58c20f):\n [] __kmalloc_cache_noprof+0x2be/0x350\n [] open_cached_dir+0x993/0x1fb0\n [] cifs_readdir+0x15a0/0x1d50\n [] iterate_dir+0x28f/0x4b0\n [] __x64_sys_getdents64+0xfd/0x200\n [] do_syscall_64+0x95/0x1a0\n [] entry_SYSCALL_64_after_hwframe+0x76/0x7e\nunreferenced object 0xffff8881044fdcf8 (size 8):\n comm \"bash\", pid 1860, jiffies 4295126592\n hex dump (first 8 bytes):\n 00 cc cc cc cc cc cc cc ........\n backtrace (crc 10c106a9):\n [] __kmalloc_node_track_caller_noprof+0x363/0x480\n [] kstrdup+0x36/0x60\n [] open_cached_dir+0x9b0/0x1fb0\n [] cifs_readdir+0x15a0/0x1d50\n [] iterate_dir+0x28f/0x4b0\n [] __x64_sys_getdents64+0xfd/0x200\n [] do_syscall_64+0x95/0x1a0\n [] entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nAnd addresses these BUG splats when unmounting the SMB filesystem:\n\nBUG: Dentry ffff888140590ba0{i=1000000000080,n=/} still in use (2) [unmount of cifs cifs]\nWARNING: CPU: 3 PID: 3433 at fs/dcache.c:1536 umount_check+0xd0/0x100\nModules linked in:\nCPU: 3 UID: 0 PID: 3433 Comm: bash Not tainted 6.12.0-rc4-g850925a8133c-dirty #49\nHardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 11/12/2020\nRIP: 0010:umount_check+0xd0/0x100\nCode: 8d 7c 24 40 e8 31 5a f4 ff 49 8b 54 24 40 41 56 49 89 e9 45 89 e8 48 89 d9 41 57 48 89 de 48 c7 c7 80 e7 db ac e8 f0 72 9a ff <0f> 0b 58 31 c0 5a 5b 5d 41 5c 41 5d 41 5e 41 5f e9 2b e5 5d 01 41\nRSP: 0018:ffff88811cc27978 EFLAGS: 00010286\nRAX: 0000000000000000 RBX: ffff888140590ba0 RCX: ffffffffaaf20bae\nRDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffff8881f6fb6f40\nRBP: ffff8881462ec000 R08: 0000000000000001 R09: ffffed1023984ee3\nR10: ffff88811cc2771f R11: 00000000016cfcc0 R12: ffff888134383e08\nR13: 0000000000000002 R14: ffff8881462ec668 R15: ffffffffaceab4c0\nFS: 00007f23bfa98740(0000) GS:ffff8881f6f80000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000556de4a6f808 CR3: 0000000123c80000 CR4: 0000000000350ef0\nCall Trace:\n \n d_walk+0x6a/0x530\n shrink_dcache_for_umount+0x6a/0x200\n generic_shutdown_super+0x52/0x2a0\n kill_anon_super+0x22/0x40\n cifs_kill_sb+0x159/0x1e0\n deactivate_locked_super+0x66/0xe0\n cleanup_mnt+0x140/0x210\n task_work_run+0xfb/0x170\n syscall_exit_to_user_mode+0x29f/0x2b0\n do_syscall_64+0xa1/0x1a0\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\nRIP: 0033:0x7f23bfb93ae7\nCode: ff ff ff ff c3 66 0f 1f 44 00 00 48 8b 0d 11 93 0d 00 f7 d8 64 89 01 b8 ff ff ff ff eb bf 0f 1f 44 00 00 b8 50 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e9 92 0d 00 f7 d8 64 89 \n---truncated---" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "baseScore": 7.5, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:N - The SMB client's cached-dir code reacts directly to remote peer behaviour — a malicious or compromised SMB server, or an on-path attacker able to drop/reset the tcp/445 connection, sets `tcon->need_reconnect` (via `cifs_reconnect()` or a `STATUS_NETWORK_NAME_DELETED` response) and thereby drives `invalidate_all_cached_dirs()` into the window that leaks the cfid.\nAC:L - The attacker controls the reconnect side and can force it repeatedly; moreover `open_cached_dir()` triggers the reconnect synchronously inside `SMB2_open_init()` once `need_reconnect` is set, so the leak is deterministic rather than a race that must be won, and each leak pins another dentry/inode.\nPR:N - No credentials or privileges on the target client are needed — the attack originates from the server/network side, and the client-side trigger is an ordinary unprivileged `getdents64()`/`stat` on the mount performed by any process or background daemon.\nUI:N - Against an already-mounted share (fstab/autofs/automounted corporate file server) no victim action is required; routine directory access by any existing process supplies the `open_cached_dir()` call while the attacker forces reconnection.\nS:U - The leaked refcount, exhausted memory and resulting BUG are all confined to the kernel of the affected client; no security boundary such as a VM or IOMMU domain is crossed.\nC:N - The defect is an over-reference/leak, not an under-reference or out-of-bounds access; no freed or out-of-bounds memory is read and no kernel data is disclosed to the attacker.\nI:N - Nothing is written out of bounds and no freed object is reused, so the bug provides no mechanism to modify kernel or user data.\nA:H - Each triggered leak permanently loses a `cached_fid`, its path string and a pinned dentry/inode, so repeated triggering exhausts memory, and unmounting the share hits `umount_check` WARN plus `VFS: Busy inodes after unmount` → `BUG()` at fs/super.c:661 (or `VFS_PTR_POISON`ed inodes that crash on later use) — a hard kernel crash." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/smb/client/cached_dir.c" ], "versions": [ { "version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7", "lessThan": "31fabf70d58388d5475e48ca8a6b7d2847b36678", "status": "affected", "versionType": "git" }, { "version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7", "lessThan": "1d76332d783db12684b67592f1fb2057b88af4c3", "status": "affected", "versionType": "git" }, { "version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7", "lessThan": "73a57b25b4df23f22814fc06b7e8f9cf570be026", "status": "affected", "versionType": "git" }, { "version": "ebe98f1447bbccf8228335c62d86af02a0ed23f7", "lessThan": "7afb86733685c64c604d32faf00fa4a1f22c2ab1", "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/smb/client/cached_dir.c" ], "versions": [ { "version": "6.1", "status": "affected" }, { "version": "0", "lessThan": "6.1", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.64", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.11", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.2", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.6.64" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.11.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.12.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1", "versionEndExcluding": "6.13" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/31fabf70d58388d5475e48ca8a6b7d2847b36678" }, { "url": "https://git.kernel.org/stable/c/1d76332d783db12684b67592f1fb2057b88af4c3" }, { "url": "https://git.kernel.org/stable/c/73a57b25b4df23f22814fc06b7e8f9cf570be026" }, { "url": "https://git.kernel.org/stable/c/7afb86733685c64c604d32faf00fa4a1f22c2ab1" } ], "title": "smb: Don't leak cfid when reconnect races with open_cached_dir", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "cvssV3_1": { "scope": "UNCHANGED", "version": "3.1", "baseScore": 4.7, "attackVector": "LOCAL", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "HIGH", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE" } }, { "other": { "type": "ssvc", "content": { "id": "CVE-2024-53178", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2025-10-01T20:04:23.545545Z" } } } ], "problemTypes": [ { "descriptions": [ { "lang": "en", "type": "CWE", "cweId": "CWE-401", "description": "CWE-401 Missing Release of Memory after Effective Lifetime" } ] } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2025-10-01T20:07:21.785Z" } } ] } }