{"api_version":"1","generated_at":"2026-10-15T23:43:34+00:00","cve":"CVE-2023-54227","urls":{"html":"https://cve.report/CVE-2023-54227","api":"https://cve.report/api/cve/CVE-2023-54227.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2023-54227","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2023-54227"},"summary":{"title":"blk-mq: fix tags leak when shrink nr_hw_queues","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix tags leak when shrink nr_hw_queues\n\nAlthough we don't need to realloc set->tags[] when shrink nr_hw_queues,\nwe need to free them. Or these tags will be leaked.\n\nHow to reproduce:\n1. mount -t configfs configfs /mnt\n2. modprobe null_blk nr_devices=0 submit_queues=8\n3. mkdir /mnt/nullb/nullb0\n4. echo 1 > /mnt/nullb/nullb0/power\n5. echo 4 > /mnt/nullb/nullb0/submit_queues\n6. rmdir /mnt/nullb/nullb0\n\nIn step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then\nin step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue).\nAt last in step 6, only these 5 tags are freed, the other 4 tags leaked.","state":"PUBLISHED","assigner":"Linux","published_at":"2025-12-30 13:16:11","updated_at":"2026-10-15 22:17:55"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.5","severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","data":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/c0ef7493e68b8896806a2f598fcffbaa97333405","name":"https://git.kernel.org/stable/c/c0ef7493e68b8896806a2f598fcffbaa97333405","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/26d495f0f64d8cd4fcd29206ee5c653ee0e0cbcd","name":"https://git.kernel.org/stable/c/26d495f0f64d8cd4fcd29206ee5c653ee0e0cbcd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/e1dd7bc93029024af5688253b0c05181d6e01f8e","name":"https://git.kernel.org/stable/c/e1dd7bc93029024af5688253b0c05181d6e01f8e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2023-54227","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-54227","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a846a8e6c9a5949582c5a6a8bbc83a7d27fd891e 26d495f0f64d8cd4fcd29206ee5c653ee0e0cbcd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a846a8e6c9a5949582c5a6a8bbc83a7d27fd891e c0ef7493e68b8896806a2f598fcffbaa97333405 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected a846a8e6c9a5949582c5a6a8bbc83a7d27fd891e e1dd7bc93029024af5688253b0c05181d6e01f8e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 5.16","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 5.16 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.1.189 6.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.5.5 6.5.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2023","cve_id":"54227","cve":"CVE-2023-54227","epss":"0.005110000","percentile":"0.414810000","score_date":"2026-10-05","updated_at":"2026-10-06 00:14:18"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"adp":[{"metrics":[{"other":{"content":{"id":"CVE-2023-54227","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"partial"}],"role":"CISA 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Vulnrichment"}],"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["block/blk-mq.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"26d495f0f64d8cd4fcd29206ee5c653ee0e0cbcd","status":"affected","version":"a846a8e6c9a5949582c5a6a8bbc83a7d27fd891e","versionType":"git"},{"lessThan":"c0ef7493e68b8896806a2f598fcffbaa97333405","status":"affected","version":"a846a8e6c9a5949582c5a6a8bbc83a7d27fd891e","versionType":"git"},{"lessThan":"e1dd7bc93029024af5688253b0c05181d6e01f8e","status":"affected","version":"a846a8e6c9a5949582c5a6a8bbc83a7d27fd891e","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["block/blk-mq.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"5.16"},{"lessThan":"5.16","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.1.*","status":"unaffected","version":"6.1.189","versionType":"semver"},{"lessThanOrEqual":"6.5.*","status":"unaffected","version":"6.5.5","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"6.6","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.1.189","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.5.5","versionStartIncluding":"5.16","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6","versionStartIncluding":"5.16","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix tags leak when shrink nr_hw_queues\n\nAlthough we don't need to realloc set->tags[] when shrink nr_hw_queues,\nwe need to free them. Or these tags will be leaked.\n\nHow to reproduce:\n1. mount -t configfs configfs /mnt\n2. modprobe null_blk nr_devices=0 submit_queues=8\n3. mkdir /mnt/nullb/nullb0\n4. echo 1 > /mnt/nullb/nullb0/power\n5. echo 4 > /mnt/nullb/nullb0/submit_queues\n6. rmdir /mnt/nullb/nullb0\n\nIn step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then\nin step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue).\nAt last in step 6, only these 5 tags are freed, the other 4 tags leaked."}],"metrics":[{"cvssV3_1":{"baseScore":7.5,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:N - The shrink is driven by remote-peer data on NVMe-oF hosts — `nvme_set_queue_count()` takes the I/O queue count verbatim from the target's Set Features completion and feeds it to `blk_mq_update_nr_hw_queues()` on every reconnect, with the tag set persisting across reconnects. A hostile/compromised target or on-path attacker on an unauthenticated NVMe/TCP fabric reaches the vulnerable code over the network.\nAC:L - The attacker fully controls the granted queue count in each Set Features response and can force reconnects at will by closing the transport connection, so each shrink→grow cycle is triggered deterministically with no conditions outside the attacker's control.\nPR:N - The remote peer needs no credentials on the victim host; NVMe/TCP in the affected 5.16–6.5 range has no in-band authentication or TLS, and the queue-count negotiation happens automatically during controller reconnect.\nUI:N - Reconnect and queue renegotiation are fully automatic in the nvme fabrics keep-alive/reconnect path; no administrator or user action is needed at exploitation time.\nS:U - The leaked allocations and the resulting memory pressure are confined to the kernel of the affected host; no security authority boundary such as a VM or IOMMU domain is crossed.\nC:N - The leaked `blk_mq_tags` and request pages are simply never freed — they are not read, exposed, or transmitted anywhere, so no information is disclosed to the attacker.\nI:N - No out-of-bounds write, use-after-free, or type confusion occurs; the stale pointers are only dropped, leaving no primitive to modify kernel or user data.\nA:H - Because the regrow path memcpy's only the shrunken count and frees the old array, every shrink→grow cycle permanently leaks a full per-queue request pool, making the leak unbounded and repeatable until kernel memory is exhausted and the system OOMs or hangs."}]}],"providerMetadata":{"dateUpdated":"2026-10-03T10:55:05.417Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/26d495f0f64d8cd4fcd29206ee5c653ee0e0cbcd"},{"url":"https://git.kernel.org/stable/c/c0ef7493e68b8896806a2f598fcffbaa97333405"},{"url":"https://git.kernel.org/stable/c/e1dd7bc93029024af5688253b0c05181d6e01f8e"}],"title":"blk-mq: fix tags leak when shrink nr_hw_queues","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2023-54227","datePublished":"2025-12-30T12:11:20.207Z","dateReserved":"2025-12-30T12:06:44.502Z","dateUpdated":"2026-10-15T21:41:42.461Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2025-12-30 13:16:11","lastModifiedDate":"2026-10-15 22:17:55","problem_types":[],"metrics":{"cvssMetricV31":[{"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","cvssData":{"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","attackVector":"NETWORK","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"NONE","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"NONE","availabilityImpact":"HIGH"},"exploitabilityScore":3.9,"impactScore":3.6}],"ssvcV203":[{"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0","ssvcData":{"timestamp":"2026-10-15T21:39:33.828518Z","id":"CVE-2023-54227","options":[{"exploitation":"none"},{"automatable":"yes"},{"technicalImpact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}]},"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2023","CveId":"54227","Ordinal":"1","Title":"blk-mq: fix tags leak when shrink nr_hw_queues","CVE":"CVE-2023-54227","Year":"2023"},"notes":[{"CveYear":"2023","CveId":"54227","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix tags leak when shrink nr_hw_queues\n\nAlthough we don't need to realloc set->tags[] when shrink nr_hw_queues,\nwe need to free them. Or these tags will be leaked.\n\nHow to reproduce:\n1. mount -t configfs configfs /mnt\n2. modprobe null_blk nr_devices=0 submit_queues=8\n3. mkdir /mnt/nullb/nullb0\n4. echo 1 > /mnt/nullb/nullb0/power\n5. echo 4 > /mnt/nullb/nullb0/submit_queues\n6. rmdir /mnt/nullb/nullb0\n\nIn step 4, will alloc 9 tags (8 submit queues and 1 poll queue), then\nin step 5, new_nr_hw_queues = 5 (4 submit queues and 1 poll queue).\nAt last in step 6, only these 5 tags are freed, the other 4 tags leaked.","Type":"Description","Title":"blk-mq: fix tags leak when shrink nr_hw_queues"}]}}}