{"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"}}}}