{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-54088", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-24T13:02:52.515Z", "datePublished": "2025-12-24T13:06:18.216Z", "dateUpdated": "2026-08-05T09:17:07.550Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:17:07.550Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-cgroup: hold queue_lock when removing blkg->q_node\n\nWhen blkg is removed from q->blkg_list from blkg_free_workfn(), queue_lock\nhas to be held, otherwise, all kinds of bugs(list corruption, hard lockup,\n..) can be triggered from blkg_destroy_all()." } ], "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 bug is in the block cgroup layer (block/blk-cgroup.c) and is reached only through local operations — cgroup v2 mkdir/rmdir, block I/O to a device, and writes to io.* cgroup control files or disk teardown. No network-facing code path touches q->blkg_list.\nAC:L - The attacker drives both sides of the race: cgroup rmdir plus prior I/O queues many blkg_free_workfn() instances that do the unlocked list_del_init(&blkg->q_node), while a concurrent io.latency write (blk_iolatency_init -> blkcg_activate_policy) or disk teardown (blkg_destroy_all) walks q->blkg_list under queue_lock only. The window can be widened arbitrarily by creating thousands of blkgs and freeing them in bulk, and pd_free_fn() work inside the mutex lengthens it further.\nPR:L - An unprivileged local user suffices in the standard deployment where a cgroup v2 subtree is delegated (systemd user@.service, rootless containers): the user owns the io.* files in cgroups they create, so they can create/destroy blkgs and trigger policy activation. No real root or CAP_SYS_ADMIN in the init namespace is needed.\nUI:N - The race is triggered entirely by the attacker's own processes issuing I/O and manipulating their cgroups; no victim action is required.\nS:U - Corruption stays within the kernel's own security authority — this is a standard kernel memory-corruption/privilege-escalation primitive with no crossing of a VM, IOMMU, or hypervisor boundary.\nC:H - The unsynchronized list_del_init() lets list_for_each_entry_safe() in blkg_destroy_all() and the walkers in blkcg_activate_policy() follow stale next pointers into a blkcg_gq that blkg_free_workfn() then kfree()s, so the kernel reads and dereferences attacker-sprayable reclaimed slab contents — a use-after-free read that yields an arbitrary kernel-memory disclosure primitive.\nI:H - After the list is corrupted the kernel writes through the dangling entry: blkg->pd[pol->plid] = pd, pd->online = false, radix_tree_delete(), hlist_del_init_rcu(), rcu_assign_pointer(blkcg->blkg_hint, NULL) and percpu_ref_kill() all operate on freed/reallocated memory, giving controlled pointer writes and indirect calls suitable for privilege escalation.\nA:H - The commit message states that list corruption and hard lockup are directly triggerable from blkg_destroy_all(); a corrupted doubly-linked list walked under spin_lock_irq loops forever or oopses, panicking the machine." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "block/blk-cgroup.c" ], "versions": [ { "version": "81c1188905f88b77743d1fdeeedfc8cb7b67787d", "lessThan": "b5dae1cd0d8368b4338430ff93403df67f0b8bcc", "status": "affected", "versionType": "git" }, { "version": "bfe46d2efe46c5c952f982e2ca94fe2ec5e58e2a", "lessThan": "083b58373463a6e5ee60ecb135269348f68ad7df", "status": "affected", "versionType": "git" }, { "version": "f1c006f1c6850c14040f8337753a63119bba39b9", "lessThan": "cd4ffdf56791eec95af01f06bee1ec7665ca75c4", "status": "affected", "versionType": "git" }, { "version": "f1c006f1c6850c14040f8337753a63119bba39b9", "lessThan": "c164c7bc9775be7bcc68754bb3431fce5823822e", "status": "affected", "versionType": "git" }, { "version": "6.1.16", "lessThan": "6.1.17", "status": "affected", "versionType": "semver" }, { "version": "6.2.3", "lessThan": "6.2.4", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "block/blk-cgroup.c" ], "versions": [ { "version": "6.3", "status": "affected" }, { "version": "0", "lessThan": "6.3", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.17", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2.4", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.12", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5", "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": "6.1.16", "versionEndExcluding": "6.1.17" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.2.3", "versionEndExcluding": "6.2.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.4.12" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.3", "versionEndExcluding": "6.5" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/b5dae1cd0d8368b4338430ff93403df67f0b8bcc" }, { "url": "https://git.kernel.org/stable/c/083b58373463a6e5ee60ecb135269348f68ad7df" }, { "url": "https://git.kernel.org/stable/c/cd4ffdf56791eec95af01f06bee1ec7665ca75c4" }, { "url": "https://git.kernel.org/stable/c/c164c7bc9775be7bcc68754bb3431fce5823822e" } ], "title": "blk-cgroup: hold queue_lock when removing blkg->q_node", "x_generator": { "engine": "bippy-1.2.0" } } } }