{"api_version":"1","generated_at":"2026-10-01T19:48:54+00:00","cve":"CVE-2026-97520","urls":{"html":"https://cve.report/CVE-2026-97520","api":"https://cve.report/api/cve/CVE-2026-97520.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-97520","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-97520"},"summary":{"title":"gfs2: move quota_init qc iterator increment","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: move quota_init qc iterator increment\n\nMove qc++ from the loop body into the for-loop increment\nexpression in gfs2_quota_init().\n\nThis keeps iterator progression explicit and avoids mixing pointer\nadvance with duplicate-slot handling in the loop body.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-09-24 17:17:30","updated_at":"2026-09-28 06:16:38"},"problem_types":[],"metrics":[{"version":"3.1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","type":"Secondary","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","data":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","baseScore":7.1,"baseSeverity":"HIGH","attackVector":"LOCAL","attackComplexity":"LOW","privilegesRequired":"NONE","userInteraction":"REQUIRED","scope":"UNCHANGED","confidentialityImpact":"NONE","integrityImpact":"HIGH","availabilityImpact":"HIGH"}},{"version":"3.1","source":"CNA","type":"DECLARED","score":"7.1","severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","data":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","version":"3.1"}}],"references":[{"url":"https://git.kernel.org/stable/c/21a50a9373adab35ffadf5cf59272dc99078170e","name":"https://git.kernel.org/stable/c/21a50a9373adab35ffadf5cf59272dc99078170e","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/04ec2f3b29b3c8a59950b8816b5ebc8ba052808a","name":"https://git.kernel.org/stable/c/04ec2f3b29b3c8a59950b8816b5ebc8ba052808a","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/942202677f8f2ee448a6a2feb06aeeaf520342e3","name":"https://git.kernel.org/stable/c/942202677f8f2ee448a6a2feb06aeeaf520342e3","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-97520","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-97520","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected de0d95c26c41c1776e4d23b1a8b3f2bcfd1dae5f 04ec2f3b29b3c8a59950b8816b5ebc8ba052808a git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected de0d95c26c41c1776e4d23b1a8b3f2bcfd1dae5f 21a50a9373adab35ffadf5cf59272dc99078170e git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected de0d95c26c41c1776e4d23b1a8b3f2bcfd1dae5f 942202677f8f2ee448a6a2feb06aeeaf520342e3 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.11","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.11 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.111 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.53 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":{"cve_year":"2026","cve_id":"97520","cve":"CVE-2026-97520","epss":"0.001210000","percentile":"0.016900000","score_date":"2026-09-29","updated_at":"2026-09-30 00:11:23"},"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/gfs2/quota.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"04ec2f3b29b3c8a59950b8816b5ebc8ba052808a","status":"affected","version":"de0d95c26c41c1776e4d23b1a8b3f2bcfd1dae5f","versionType":"git"},{"lessThan":"21a50a9373adab35ffadf5cf59272dc99078170e","status":"affected","version":"de0d95c26c41c1776e4d23b1a8b3f2bcfd1dae5f","versionType":"git"},{"lessThan":"942202677f8f2ee448a6a2feb06aeeaf520342e3","status":"affected","version":"de0d95c26c41c1776e4d23b1a8b3f2bcfd1dae5f","versionType":"git"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/gfs2/quota.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.11"},{"lessThan":"6.11","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.111","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.53","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.111","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.53","versionStartIncluding":"6.11","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2","versionStartIncluding":"6.11","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: move quota_init qc iterator increment\n\nMove qc++ from the loop body into the for-loop increment\nexpression in gfs2_quota_init().\n\nThis keeps iterator progression explicit and avoids mixing pointer\nadvance with duplicate-slot handling in the loop body."}],"metrics":[{"cvssV3_1":{"baseScore":7.1,"baseSeverity":"HIGH","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:H","version":"3.1"},"scenarios":[{"lang":"en","value":"AV:L - The malformed bytes are on-disk struct gfs2_quota_change records in the per-node quota_change file. gfs2_quota_init() reads them via gfs2_meta_ra() from gfs2_get_tree()→get_tree_bdev()→gfs2_fill_super()→gfs2_make_fs_rw(); no NFS/SMB/TCP message carries qc_id or qc_change.\nAC:L - A crafted quota_change file with two non-zero qc_change entries sharing qc_id, the duplicate in the last slot of a QC block, makes the pre-fix body qc++ then memset(qc,0,sizeof(*qc)) run on every read-write mount of that image, with no race.\nPR:N - Crafting the image needs no host account. gfs2_fs_type.fs_flags is only FS_REQUIRES_DEV (no FS_USERNS_MOUNT), so mount_capable() is capable(CAP_SYS_ADMIN) in init_user_ns; that privileged mount of the attacker image is scored as UI:R, not attacker privilege.\nUI:R - gfs2_quota_init() runs only from gfs2_make_fs_rw() after gfs2_fill_super() or gfs2_reconfigure() attaches the attacker-supplied block device. Because gfs2 is not FS_USERNS_MOUNT, a victim or administrator must mount that image read-write before the duplicate-slot memset runs.\nS:U - The out-of-bounds memset in gfs2_quota_init() corrupts page-cache memory in the host kernel that mounted the volume; this is not a KVM/Xen guest-to-host escape or an IOMMU/DMA bypass.\nC:N - The duplicate path only stores 16 zeros through the already-advanced qc pointer; it does not load adjacent kernel bytes or copy them to userspace.\nI:H - Pre-fix, qc++ runs before memset(qc,0,sizeof(*qc)). sd_qc_per_block is (sb_bsize-24)/16, leaving 8 bytes of padding, so a last-slot duplicate stores 8 zeros past bh->b_data+sb_bsize of the gfs2_getbuf() buffer_head: a kernel out-of-bounds write.\nA:H - Those 8 zeros past the QC buffer_head land in the next folio/page (or the next BH in the same folio when sb_bsize