{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53608", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-04T15:40:38.480Z", "datePublished": "2025-10-04T15:44:17.302Z", "dateUpdated": "2026-08-05T09:15:06.157Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:15:06.157Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()\n\nThe finalization of nilfs_segctor_thread() can race with\nnilfs_segctor_kill_thread() which terminates that thread, potentially\ncausing a use-after-free BUG as KASAN detected.\n\nAt the end of nilfs_segctor_thread(), it assigns NULL to \"sc_task\" member\nof \"struct nilfs_sc_info\" to indicate the thread has finished, and then\nnotifies nilfs_segctor_kill_thread() of this using waitqueue\n\"sc_wait_task\" on the struct nilfs_sc_info.\n\nHowever, here, immediately after the NULL assignment to \"sc_task\", it is\npossible that nilfs_segctor_kill_thread() will detect it and return to\ncontinue the deallocation, freeing the nilfs_sc_info structure before the\nthread does the notification.\n\nThis fixes the issue by protecting the NULL assignment to \"sc_task\" and\nits notification, with spinlock \"sc_state_lock\" of the struct\nnilfs_sc_info. Since nilfs_segctor_kill_thread() does a final check to\nsee if \"sc_task\" is NULL with \"sc_state_lock\" locked, this can eliminate\nthe race." } ], "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 is only reachable through local filesystem operations — mount(2)/umount(2) of a nilfs2 volume (or the mount-time rollforward recovery attach/detach in nilfs_salvage_orphan_logs()). No network or peer-supplied data reaches nilfs_segctor_thread()/nilfs_segctor_kill_thread().\nAC:L - The attacker creates both sides of the race: the unmount/teardown request is what wakes the segctord kthread and drives it to end_thread, and the attempt can be repeated indefinitely via mount/unmount cycles (a recovery-requiring image makes even a plain mount start and kill the thread), with the preemption window widened by ordinary CPU contention.\nPR:L - An unprivileged local user reaches the teardown path on any ordinary desktop/kiosk through removable-media automount (udisks2/autofs mounts and unmounts a nilfs2 volume on the session user's behalf) or `user` fstab entries; no capability check is performed inside the racing code itself, consistent with other unmount-path filesystem teardown CVEs.\nUI:N - The attacker performs the mount/unmount cycling themselves; no separate victim has to open a file, run a command, or take any action for the race to be triggered.\nS:U - The use-after-free corrupts kernel heap memory within the same kernel security authority; no VM, IOMMU, container, or sandbox boundary is crossed.\nC:H - After kfree(sci) the kthread's wake_up() walks sci->sc_wait_task's list from the freed ~kmalloc-512 slot, so a reclaiming spray lets the attacker steer the traversal and the curr->func() indirect call, yielding kernel-memory disclosure; per UAF guidance this is High.\nI:H - wake_up() on the freed object performs a spinlock write into freed memory, list_del-style pointer writes on attacker-controlled list entries, and an indirect call through curr->func — a write and control-flow-hijack primitive exploitable for privilege escalation.\nA:H - The bug was reported by syzbot as a KASAN-detected use-after-free BUG; locking and dereferencing freed slab memory reliably produces an oops or panic even without successful exploitation." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "fs/nilfs2/segment.c" ], "versions": [ { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "034cce77d52ba013ce62b4f5258c29907eb1ada5", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "0dbf0e64b91ee8fcb278aea93eb06fc7d56ecbcc", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "613bf23c070d11c525268f2945aa594704a9b764", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "f32297dba338dc06d62286dedb3cdbd5175b1719", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "92684e02654c91a61a0b0561433b710bcece19fe", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "bae009a2f1b7c2011d2e92d8c84868d315c0b97e", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "b4d80bd6370b81a1725b6b8f7894802c23a14e9f", "status": "affected", "versionType": "git" }, { "version": "9ff05123e3bfbb1d2b68ba1d9bf1f7d1dffc1453", "lessThan": "6be49d100c22ffea3287a4b19d7639d259888e33", "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/nilfs2/segment.c" ], "versions": [ { "version": "2.6.30", "status": "affected" }, { "version": "0", "lessThan": "2.6.30", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.313", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.281", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.241", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.178", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.107", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.24", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2.11", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3", "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": "2.6.30", "versionEndExcluding": "4.14.313" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "4.19.281" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "5.4.241" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "5.10.178" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "5.15.107" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.1.24" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.2.11" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.30", "versionEndExcluding": "6.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/034cce77d52ba013ce62b4f5258c29907eb1ada5" }, { "url": "https://git.kernel.org/stable/c/0dbf0e64b91ee8fcb278aea93eb06fc7d56ecbcc" }, { "url": "https://git.kernel.org/stable/c/613bf23c070d11c525268f2945aa594704a9b764" }, { "url": "https://git.kernel.org/stable/c/f32297dba338dc06d62286dedb3cdbd5175b1719" }, { "url": "https://git.kernel.org/stable/c/92684e02654c91a61a0b0561433b710bcece19fe" }, { "url": "https://git.kernel.org/stable/c/bae009a2f1b7c2011d2e92d8c84868d315c0b97e" }, { "url": "https://git.kernel.org/stable/c/b4d80bd6370b81a1725b6b8f7894802c23a14e9f" }, { "url": "https://git.kernel.org/stable/c/6be49d100c22ffea3287a4b19d7639d259888e33" } ], "title": "nilfs2: fix potential UAF of struct nilfs_sc_info in nilfs_segctor_thread()", "x_generator": { "engine": "bippy-1.2.0" } } } }