{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2024-47679", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-09-30T16:00:12.939Z", "datePublished": "2024-10-21T11:53:22.469Z", "dateUpdated": "2026-08-05T11:39:25.078Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:39:25.078Z" }, "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." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The race requires local syscalls — `umount()` to drive `generic_shutdown_super()`→`evict_inodes()` plus concurrent `open()`/`close()` to drive `find_inode()`/`iput()` on the same inode. No network protocol handler reaches this path.\nAC:L - The attacker controls every side of the race: it stages inodes at `i_count==0` with page cache (making `__inode_add_lru()` bail), hammers lookups on them from parallel threads, and issues the unmount itself, retrying the whole cycle indefinitely until the window between the unlocked `atomic_read(&inode->i_count)` and `spin_lock(&inode->i_lock)` is hit; syzbot reproduced it automatically.\nPR:L - An ordinary unprivileged user can mount and unmount FUSE or overlayfs inside a user namespace (`FS_USERNS_MOUNT`, `unshare -Urm`), and FUSE's `iget5_locked()` lookups supply the racing `find_inode()`; no real root or init-namespace capability is needed.\nUI:N - The attacker performs the mount, the file accesses, and the unmount entirely on its own; no action by another user or administrator is required.\nS:U - The corruption stays within the kernel of the same machine — a standard local kernel memory-safety issue with no crossing of a VM, hypervisor, or IOMMU boundary.\nC:H - Double eviction leads to `destroy_inode()` twice on the same slab object, a double-free/UAF the attacker can reclaim with controlled data, yielding an arbitrary kernel-memory read primitive and disclosure of any data on the system.\nI:H - The same double-free/UAF on the inode cache allows heap grooming and type confusion between the stale inode and a reclaimed object, giving arbitrary kernel write and a realistic path to privilege escalation.\nA:H - The immediate observable effect is `BUG_ON(inode->i_state & I_CLEAR)` in `clear_inode()` and `BUG_ON(inode->i_state != (I_FREEING|I_CLEAR))` in `evict()`, i.e. a kernel panic, and the slab double-free crashes the system even when not exploited further." } ] } ], "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": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "6cc13a80a26e6b48f78c725c01b91987d61563ef", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "489faddb1ae75b0e1a741fe5ca2542a2b5e794a5", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "47a68c75052a660e4c37de41e321582ec9496195", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "3721a69403291e2514d13a7c3af50a006ea1153b", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "540fb13120c9eab3ef203f90c00c8e69f37449d1", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "0eed942bc65de1f93eca7bda51344290f9c573bb", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "0f8a5b6d0dafa4f533ac82e98f8b812073a7c9d1", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "6c857fb12b9137fee574443385d53914356bbe11", "status": "affected", "versionType": "git" }, { "version": "63997e98a3be68d7cec806d22bf9b02b2e1daabb", "lessThan": "88b1afbf0f6b221f6c5bb66cc80cd3b38d696687", "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": "semver" }, { "version": "4.19.323", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.285", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.227", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.168", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.113", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.54", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.10.13", "lessThanOrEqual": "6.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.11.2", "lessThanOrEqual": "6.11.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12", "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": "2.6.37", "versionEndExcluding": "4.19.323" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.4.285" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.10.227" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "5.15.168" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.1.113" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.6.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.10.13" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.11.2" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.37", "versionEndExcluding": "6.12" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/6cc13a80a26e6b48f78c725c01b91987d61563ef" }, { "url": "https://git.kernel.org/stable/c/489faddb1ae75b0e1a741fe5ca2542a2b5e794a5" }, { "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-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2024-47679", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "partial" } ], "version": "2.0.3", "timestamp": "2024-10-21T13:07:33.659444Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2024-10-21T13:14:16.951Z" } }, { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T22:20:46.317Z" } } ] } }