{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2025-37856", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.956Z", "datePublished": "2025-05-09T06:42:04.315Z", "dateUpdated": "2026-05-23T15:58:25.284Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-05-23T15:58:25.284Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: harden block_group::bg_list against list_del() races\n\nAs far as I can tell, these calls of list_del_init() on bg_list cannot\nrun concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(),\nas they are in transaction error paths and situations where the block\ngroup is readonly.\n\nHowever, if there is any chance at all of racing with mark_bg_unused(),\nor a different future user of bg_list, better to be safe than sorry.\n\nOtherwise we risk the following interleaving (bg_list refcount in parens)\n\nT1 (some random op) T2 (btrfs_mark_bg_unused)\n !list_empty(&bg->bg_list); (1)\nlist_del_init(&bg->bg_list); (1)\n list_move_tail (1)\nbtrfs_put_block_group (0)\n btrfs_delete_unused_bgs\n bg = list_first_entry\n list_del_init(&bg->bg_list);\n btrfs_put_block_group(bg); (-1)\n\nUltimately, this results in a broken ref count that hits zero one deref\nearly and the real final deref underflows the refcount, resulting in a WARNING."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/btrfs/extent-tree.c", "fs/btrfs/transaction.c"], "versions": [{"version": "a9f189716cf15913c453299d72f69c51a9b0f86b", "lessThan": "bf089c4d1141b27332c092b1dcca5022c415a3b6", "status": "affected", "versionType": "git"}, {"version": "a9f189716cf15913c453299d72f69c51a9b0f86b", "lessThan": "909e60fb469d4101c6b08cf6e622efb062bb24a1", "status": "affected", "versionType": "git"}, {"version": "a9f189716cf15913c453299d72f69c51a9b0f86b", "lessThan": "185fd73e5ac06027c4be9a129e59193f6a3ef202", "status": "affected", "versionType": "git"}, {"version": "a9f189716cf15913c453299d72f69c51a9b0f86b", "lessThan": "7511e29cf1355b2c47d0effb39e463119913e2f6", "status": "affected", "versionType": "git"}, {"version": "edf3b5aadb2515c808200b904baa5b70a727f0ac", "status": "affected", "versionType": "git"}, {"version": "01eca70ef8cf499d0cb6d1bbd691558e7792cf17", "status": "affected", "versionType": "git"}, {"version": "5d19abcffd8404078dfa7d7118cec357b5e7bc58", "status": "affected", "versionType": "git"}, {"version": "5.15.128", "lessThan": "5.16", "status": "affected", "versionType": "semver"}, {"version": "6.1.47", "lessThan": "6.2", "status": "affected", "versionType": "semver"}, {"version": "6.4.12", "lessThan": "6.5", "status": "affected", "versionType": "semver"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/btrfs/extent-tree.c", "fs/btrfs/transaction.c"], "versions": [{"version": "6.5", "status": "affected"}, {"version": "0", "lessThan": "6.5", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.24", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.13.12", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.14.3", "lessThanOrEqual": "6.14.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.15", "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": "6.5", "versionEndExcluding": "6.12.24"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.13.12"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.14.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.5", "versionEndExcluding": "6.15"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.15.128"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.1.47"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.4.12"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/bf089c4d1141b27332c092b1dcca5022c415a3b6"}, {"url": "https://git.kernel.org/stable/c/909e60fb469d4101c6b08cf6e622efb062bb24a1"}, {"url": "https://git.kernel.org/stable/c/185fd73e5ac06027c4be9a129e59193f6a3ef202"}, {"url": "https://git.kernel.org/stable/c/7511e29cf1355b2c47d0effb39e463119913e2f6"}], "title": "btrfs: harden block_group::bg_list against list_del() races", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{"configurations": [{"nodes": [{"cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "C87CF81F-5426-4E15-8A61-B8F0E6046484", "versionEndExcluding": "6.12.24", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "4A475784-BF3B-4514-81EE-49C8522FB24A", "versionEndExcluding": "6.13.12", "versionStartIncluding": "6.13", "vulnerable": true}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "matchCriteriaId": "483E2E15-2135-4EC6-AB64-16282C5EF704", "versionEndExcluding": "6.14.3", "versionStartIncluding": "6.14", "vulnerable": true}], "negate": false, "operator": "OR"}]}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: harden block_group::bg_list against list_del() races\n\nAs far as I can tell, these calls of list_del_init() on bg_list cannot\nrun concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(),\nas they are in transaction error paths and situations where the block\ngroup is readonly.\n\nHowever, if there is any chance at all of racing with mark_bg_unused(),\nor a different future user of bg_list, better to be safe than sorry.\n\nOtherwise we risk the following interleaving (bg_list refcount in parens)\n\nT1 (some random op) T2 (btrfs_mark_bg_unused)\n !list_empty(&bg->bg_list); (1)\nlist_del_init(&bg->bg_list); (1)\n list_move_tail (1)\nbtrfs_put_block_group (0)\n btrfs_delete_unused_bgs\n bg = list_first_entry\n list_del_init(&bg->bg_list);\n btrfs_put_block_group(bg); (-1)\n\nUltimately, this results in a broken ref count that hits zero one deref\nearly and the real final deref underflows the refcount, resulting in a WARNING."}, {"lang": "es", "value": "En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: btrfs: endurecer block_group::bg_list contra ejecuciones list_del() Hasta donde puedo decir, estas llamadas de list_del_init() en bg_list no se pueden ejecutar simult\u00e1neamente con btrfs_mark_bg_unused() o btrfs_mark_bg_to_reclaim(), ya que est\u00e1n en rutas de error de transacci\u00f3n y situaciones en las que el grupo de bloques es de solo lectura. Sin embargo, si hay alguna posibilidad de competir con mark_bg_unused(), o con un futuro usuario diferente de bg_list, m\u00e1s vale prevenir que curar. De lo contrario, nos arriesgamos al siguiente intercalado (bg_list refcount entre par\u00e9ntesis) T1 (alguna operaci\u00f3n aleatoria) T2 (btrfs_mark_bg_unused) !list_empty(&bg->bg_list); (1) list_del_init(&bg->bg_list); (1) list_move_tail (1) btrfs_put_block_group (0) btrfs_delete_unused_bgs bg = list_first_entry list_del_init(&bg->bg_list); btrfs_put_block_group(bg); (-1) En \u00faltima instancia, esto da como resultado un recuento de referencias roto que llega a cero un deref antes y el deref final real desborda el recuento de referencias, lo que genera una ADVERTENCIA."}], "id": "CVE-2025-37856", "lastModified": "2025-11-12T20:08:08.820", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 5.5, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 1.8, "impactScore": 3.6, "source": "nvd@nist.gov", "type": "Primary"}]}, "published": "2025-05-09T07:16:06.593", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/185fd73e5ac06027c4be9a129e59193f6a3ef202"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/7511e29cf1355b2c47d0effb39e463119913e2f6"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/909e60fb469d4101c6b08cf6e622efb062bb24a1"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "tags": ["Patch"], "url": "https://git.kernel.org/stable/c/bf089c4d1141b27332c092b1dcca5022c415a3b6"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "NVD-CWE-noinfo"}], "source": "nvd@nist.gov", "type": "Primary"}]}

{"bugzilla": {"description": "kernel: btrfs: harden block_group::bg_list against list_del() races", "id": "2365242", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2365242"}, "csaw": false, "cvss3": {"cvss3_base_score": "5.5", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "details": ["In the Linux kernel, the following vulnerability has been resolved:\nbtrfs: harden block_group::bg_list against list_del() races\nAs far as I can tell, these calls of list_del_init() on bg_list cannot\nrun concurrently with btrfs_mark_bg_unused() or btrfs_mark_bg_to_reclaim(),\nas they are in transaction error paths and situations where the block\ngroup is readonly.\nHowever, if there is any chance at all of racing with mark_bg_unused(),\nor a different future user of bg_list, better to be safe than sorry.\nOtherwise we risk the following interleaving (bg_list refcount in parens)\nT1 (some random op) T2 (btrfs_mark_bg_unused)\n!list_empty(&bg->bg_list); (1)\nlist_del_init(&bg->bg_list); (1)\nlist_move_tail (1)\nbtrfs_put_block_group (0)\nbtrfs_delete_unused_bgs\nbg = list_first_entry\nlist_del_init(&bg->bg_list);\nbtrfs_put_block_group(bg); (-1)\nUltimately, this results in a broken ref count that hits zero one deref\nearly and the real final deref underflows the refcount, resulting in a WARNING."], "name": "CVE-2025-37856", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2025-05-09T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2025-37856\nhttps://nvd.nist.gov/vuln/detail/CVE-2025-37856\nhttps://lore.kernel.org/linux-cve-announce/2025050921-CVE-2025-37856-3117@gregkh/T"], "threat_severity": "Moderate"}

{}