{"api_version":"1","generated_at":"2026-08-15T15:07:55+00:00","cve":"CVE-2026-74572","urls":{"html":"https://cve.report/CVE-2026-74572","api":"https://cve.report/api/cve/CVE-2026-74572.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-74572","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-74572"},"summary":{"title":"btrfs: zoned: fix deadlock between metadata writeback and transaction commit","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: fix deadlock between metadata writeback and transaction commit\n\nWhen writing out metadata extent buffers in a zoned filesystem,\nbtree_writepages() holds fs_info->zoned_meta_io_lock across the whole\nwriteback loop, including the call to btrfs_check_meta_write_pointer() ->\ncheck_bg_is_active().\n\nFor the tree-log block group, check_bg_is_active() may fail to activate\nthe zone and fall back to btrfs_zone_finish_one_bg() to free an active\nzone. That path waits for the running transaction to commit while still\nholding zoned_meta_io_lock, but the committer needs that same lock to\nwrite out the tree extents, so the two tasks deadlock:\n\n  Task A (kworker, metadata writeback)      Task B (fsstress, transaction commit)\n  ------------------------------------      -------------------------------------\n  wb_workfn()                               btrfs_commit_transaction(T)\n   btree_writepages()                        btrfs_write_and_wait_transaction()\n    btrfs_zoned_meta_io_lock()                btrfs_write_marked_extents()\n    btrfs_check_meta_write_pointer()           btree_writepages()\n     check_bg_is_active() [treelog_bg]          btrfs_zoned_meta_io_lock()\n      btrfs_zone_finish_one_bg()               <blocks on zoned_meta_io_lock,\n       btrfs_zone_finish()                      held by Task A>\n        do_zone_finish()\n         btrfs_inc_block_group_ro()\n          btrfs_wait_for_commit()\n           <blocks waiting for commit\n            of transaction T, done by\n            Task B>\n\nThe sibling branch in check_bg_is_active() already drops zoned_meta_io_lock\naround do_zone_finish() for this exact reason. Do the same in the tree-log\nbranch: release the lock around btrfs_zone_finish_one_bg() and re-acquire\nit afterwards. The lock only protects fs_info->active_{meta,system}_bg,\nwhich this branch does not touch, and ctx->zoned_bg keeps a reference to\nthe block group across the unlock, so nothing is lost while the lock\nis dropped.\n\nThis hang occasionally reproduces with fstests generic/475 on a zoned\nbtrfs filesystem.","state":"PUBLISHED","assigner":"Linux","published_at":"2026-08-15 13:18:02","updated_at":"2026-08-15 13:18:02"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/1ebe51c29fa9755d5b2fea28727c051117907cf8","name":"https://git.kernel.org/stable/c/1ebe51c29fa9755d5b2fea28727c051117907cf8","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/c3320873e0c04ce7b746fc8fe948f07bbbbdec33","name":"https://git.kernel.org/stable/c/c3320873e0c04ce7b746fc8fe948f07bbbbdec33","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/75859a7cd77cd2ddaddbcb963e3fcd34738953af","name":"https://git.kernel.org/stable/c/75859a7cd77cd2ddaddbcb963e3fcd34738953af","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/deddd28fd83c264ee2ff5cd6b34449a9f1be6112","name":"https://git.kernel.org/stable/c/deddd28fd83c264ee2ff5cd6b34449a9f1be6112","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/18577e77c2c8adaadf1f7c6e9bcd1c0b14e5dcdd","name":"https://git.kernel.org/stable/c/18577e77c2c8adaadf1f7c6e9bcd1c0b14e5dcdd","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-74572","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74572","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 13bb483d32abb6f8ebd40141d87eb68f11cc2dd2 18577e77c2c8adaadf1f7c6e9bcd1c0b14e5dcdd git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 13bb483d32abb6f8ebd40141d87eb68f11cc2dd2 c3320873e0c04ce7b746fc8fe948f07bbbbdec33 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 13bb483d32abb6f8ebd40141d87eb68f11cc2dd2 deddd28fd83c264ee2ff5cd6b34449a9f1be6112 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 13bb483d32abb6f8ebd40141d87eb68f11cc2dd2 75859a7cd77cd2ddaddbcb963e3fcd34738953af git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 13bb483d32abb6f8ebd40141d87eb68f11cc2dd2 1ebe51c29fa9755d5b2fea28727c051117907cf8 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected fca3a1cd3ba47f1815e0c0fcdc9aafaf02ee0a75 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.5.5 6.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.6","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.6.151 6.6.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.12.103 6.12.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 6.18.44 6.18.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.1.8 7.1.* semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"unaffected 7.2-rc6 * original_commit_for_fix","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["fs/btrfs/zoned.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"18577e77c2c8adaadf1f7c6e9bcd1c0b14e5dcdd","status":"affected","version":"13bb483d32abb6f8ebd40141d87eb68f11cc2dd2","versionType":"git"},{"lessThan":"c3320873e0c04ce7b746fc8fe948f07bbbbdec33","status":"affected","version":"13bb483d32abb6f8ebd40141d87eb68f11cc2dd2","versionType":"git"},{"lessThan":"deddd28fd83c264ee2ff5cd6b34449a9f1be6112","status":"affected","version":"13bb483d32abb6f8ebd40141d87eb68f11cc2dd2","versionType":"git"},{"lessThan":"75859a7cd77cd2ddaddbcb963e3fcd34738953af","status":"affected","version":"13bb483d32abb6f8ebd40141d87eb68f11cc2dd2","versionType":"git"},{"lessThan":"1ebe51c29fa9755d5b2fea28727c051117907cf8","status":"affected","version":"13bb483d32abb6f8ebd40141d87eb68f11cc2dd2","versionType":"git"},{"status":"affected","version":"fca3a1cd3ba47f1815e0c0fcdc9aafaf02ee0a75","versionType":"git"},{"lessThan":"6.6","status":"affected","version":"6.5.5","versionType":"semver"}]},{"defaultStatus":"affected","product":"Linux","programFiles":["fs/btrfs/zoned.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"status":"affected","version":"6.6"},{"lessThan":"6.6","status":"unaffected","version":"0","versionType":"semver"},{"lessThanOrEqual":"6.6.*","status":"unaffected","version":"6.6.151","versionType":"semver"},{"lessThanOrEqual":"6.12.*","status":"unaffected","version":"6.12.103","versionType":"semver"},{"lessThanOrEqual":"6.18.*","status":"unaffected","version":"6.18.44","versionType":"semver"},{"lessThanOrEqual":"7.1.*","status":"unaffected","version":"7.1.8","versionType":"semver"},{"lessThanOrEqual":"*","status":"unaffected","version":"7.2-rc6","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.6.151","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.12.103","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.44","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.1.8","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2-rc6","versionStartIncluding":"6.6","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.5.5","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: fix deadlock between metadata writeback and transaction commit\n\nWhen writing out metadata extent buffers in a zoned filesystem,\nbtree_writepages() holds fs_info->zoned_meta_io_lock across the whole\nwriteback loop, including the call to btrfs_check_meta_write_pointer() ->\ncheck_bg_is_active().\n\nFor the tree-log block group, check_bg_is_active() may fail to activate\nthe zone and fall back to btrfs_zone_finish_one_bg() to free an active\nzone. That path waits for the running transaction to commit while still\nholding zoned_meta_io_lock, but the committer needs that same lock to\nwrite out the tree extents, so the two tasks deadlock:\n\n  Task A (kworker, metadata writeback)      Task B (fsstress, transaction commit)\n  ------------------------------------      -------------------------------------\n  wb_workfn()                               btrfs_commit_transaction(T)\n   btree_writepages()                        btrfs_write_and_wait_transaction()\n    btrfs_zoned_meta_io_lock()                btrfs_write_marked_extents()\n    btrfs_check_meta_write_pointer()           btree_writepages()\n     check_bg_is_active() [treelog_bg]          btrfs_zoned_meta_io_lock()\n      btrfs_zone_finish_one_bg()               <blocks on zoned_meta_io_lock,\n       btrfs_zone_finish()                      held by Task A>\n        do_zone_finish()\n         btrfs_inc_block_group_ro()\n          btrfs_wait_for_commit()\n           <blocks waiting for commit\n            of transaction T, done by\n            Task B>\n\nThe sibling branch in check_bg_is_active() already drops zoned_meta_io_lock\naround do_zone_finish() for this exact reason. Do the same in the tree-log\nbranch: release the lock around btrfs_zone_finish_one_bg() and re-acquire\nit afterwards. The lock only protects fs_info->active_{meta,system}_bg,\nwhich this branch does not touch, and ctx->zoned_bg keeps a reference to\nthe block group across the unlock, so nothing is lost while the lock\nis dropped.\n\nThis hang occasionally reproduces with fstests generic/475 on a zoned\nbtrfs filesystem."}],"providerMetadata":{"dateUpdated":"2026-08-15T12:28:11.328Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/18577e77c2c8adaadf1f7c6e9bcd1c0b14e5dcdd"},{"url":"https://git.kernel.org/stable/c/c3320873e0c04ce7b746fc8fe948f07bbbbdec33"},{"url":"https://git.kernel.org/stable/c/deddd28fd83c264ee2ff5cd6b34449a9f1be6112"},{"url":"https://git.kernel.org/stable/c/75859a7cd77cd2ddaddbcb963e3fcd34738953af"},{"url":"https://git.kernel.org/stable/c/1ebe51c29fa9755d5b2fea28727c051117907cf8"}],"title":"btrfs: zoned: fix deadlock between metadata writeback and transaction commit","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-74572","datePublished":"2026-08-15T12:28:11.328Z","dateReserved":"2026-08-15T05:44:03.917Z","dateUpdated":"2026-08-15T12:28:11.328Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-08-15 13:18:02","lastModifiedDate":"2026-08-15 13:18:02","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"74572","Ordinal":"1","Title":"btrfs: zoned: fix deadlock between metadata writeback and transa","CVE":"CVE-2026-74572","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"74572","Ordinal":"1","NoteData":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: fix deadlock between metadata writeback and transaction commit\n\nWhen writing out metadata extent buffers in a zoned filesystem,\nbtree_writepages() holds fs_info->zoned_meta_io_lock across the whole\nwriteback loop, including the call to btrfs_check_meta_write_pointer() ->\ncheck_bg_is_active().\n\nFor the tree-log block group, check_bg_is_active() may fail to activate\nthe zone and fall back to btrfs_zone_finish_one_bg() to free an active\nzone. That path waits for the running transaction to commit while still\nholding zoned_meta_io_lock, but the committer needs that same lock to\nwrite out the tree extents, so the two tasks deadlock:\n\n  Task A (kworker, metadata writeback)      Task B (fsstress, transaction commit)\n  ------------------------------------      -------------------------------------\n  wb_workfn()                               btrfs_commit_transaction(T)\n   btree_writepages()                        btrfs_write_and_wait_transaction()\n    btrfs_zoned_meta_io_lock()                btrfs_write_marked_extents()\n    btrfs_check_meta_write_pointer()           btree_writepages()\n     check_bg_is_active() [treelog_bg]          btrfs_zoned_meta_io_lock()\n      btrfs_zone_finish_one_bg()               <blocks on zoned_meta_io_lock,\n       btrfs_zone_finish()                      held by Task A>\n        do_zone_finish()\n         btrfs_inc_block_group_ro()\n          btrfs_wait_for_commit()\n           <blocks waiting for commit\n            of transaction T, done by\n            Task B>\n\nThe sibling branch in check_bg_is_active() already drops zoned_meta_io_lock\naround do_zone_finish() for this exact reason. Do the same in the tree-log\nbranch: release the lock around btrfs_zone_finish_one_bg() and re-acquire\nit afterwards. The lock only protects fs_info->active_{meta,system}_bg,\nwhich this branch does not touch, and ctx->zoned_bg keeps a reference to\nthe block group across the unlock, so nothing is lost while the lock\nis dropped.\n\nThis hang occasionally reproduces with fstests generic/475 on a zoned\nbtrfs filesystem.","Type":"Description","Title":"btrfs: zoned: fix deadlock between metadata writeback and transa"}]}}}