{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-80734", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-80734", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-09-03T08:21:50.734Z", "updatedAt": "2026-10-21T12:47:00.597Z", "importedAt": "2026-10-24T01:58:30.346Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "btrfs: initialize inode mapping flags for cached inodes", "summary": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: initialize inode mapping flags for cached inodes\n\n[BUG]\nWhen running generic/795 with 8K block size, 4K page size, the test\nalways fails, triggering some ASSERT()s related to folio size:\n\n 795 (241074): drop_caches: 3\n assertion failed: IS_ALIGNED(start, blocksize) && IS_ALIGNED(end + 1, blocksize), in extent_io.c:1404 (blocksize=8192 root=262 ino=258 start=16826368 end=16830463 mapping min order=0)\n ------------[ cut here ]------------\n kernel BUG at extent_io.c:1404!\n Oops: invalid opcode: 0000 [#1] SMP\n CPU: 8 UID: 0 PID: 241105 Comm: fsstress Tainted: G OE 7.2.0-rc5-custom+ #442 PREEMPT(full) f4bfb352566f3949f29c233ce6f735050a03b245\n Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS unknown 02/02/2022\n RIP: 0010:assert_folio_range.cold+0x3d/0x3f [btrfs]\n Call Trace:\n \n btrfs_read_folio+0x9e/0x170 [btrfs 4cd1dd93b341b8ef766643f9512f4a86259567a3]\n prepare_one_folio.constprop.0+0x104/0x2a0 [btrfs 4cd1dd93b341b8ef766643f9512f4a86259567a3]\n btrfs_buffered_write+0x285/0xa50 [btrfs 4cd1dd93b341b8ef766643f9512f4a86259567a3]\n btrfs_do_write_iter+0x1aa/0x210 [btrfs 4cd1dd93b341b8ef766643f9512f4a86259567a3]\n iter_file_splice_write+0x31a/0x540\n direct_splice_actor+0x53/0x170\n splice_direct_to_actor+0xe9/0x240\n do_splice_direct+0x76/0xb0\n vfs_copy_file_range+0x1fd/0x630\n __x64_sys_copy_file_range+0xf9/0x220\n do_syscall_64+0xe1/0x790\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n \n ---[ end trace 0000000000000000 ]---\n\nThe ASSERT() itself is added by a later patch.\nThe crash is triggered with that new debug patch, and without this fix.\n\n[CAUSE]\nIn the above case, the start 16826368 is properly 8K aligned, but the\nend (16830463 + 1) is not 8K aligned.\nFurthermore the mapping's minimal folio order is 0, not the expected 1\nfor 8K block size with 4K page size.\n\nSo this means some inodes do not have btrfs_set_inode_mapping_order()\ncalled on it.\n\nThe missing btrfs_set_inode_mapping_order() call happens for cached\ninodes, through the following events:\n\n- btrfs_create_new_inode() called for inode X\n Which properly sets minimal folio order for the VFS inode.\n\n- btrfs_update_inode() called for inode X\n Which calls btrfs_delayed_update_inode() to create a delayed_node\n into root->delayed_nodes xarray.\n\n- Drop cache/memory pressure, evicting in-memory inode X\n Which evicted the inode X, but delayed_node is still in\n root->delayed_nodes for future reuse.\n\n- btrfs_iget() for inode X called again\n\n btrfs_iget()\n |- btrfs_iget_locked()\n | |- iget5_locked_rcu()\n | Which creates a new vfs_inode for btrfs, whose mapping still\n | has the minimal order as 0.\n |\n |- btrfs_read_locked_inode()\n |- btrfs_fill_inode()\n | |- btrfs_get_delayed_node()\n | Which found out the previous node, and use that delayed\n | node to initialize the new inode.\n |\n |- filled = true;\n |- if (filled) goto cache_index;\n Which skips the btrfs_update_inode_mapping_flags() and\n\tbtrfs_set_inode_mapping_order() calls.\n\tSo the inode still has minimal folio order set as 0, not\n\tthe required 1.\n\nThus later page cache read will get a folio whose size is smaller than\nblock size, as the mapping has its minimal folio order set as 0 not 1,\nthen trigger the ASSERT().\n\n[FIX]\nMove the btrfs_update_inode_mapping_flags() and\nbtrfs_set_inode_mapping_order() calls under cache_index label,\nso that the mapping flags and minimal folio order is always set\nno matter if we have a cached inode.", "affected": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "01b002151539a4c2b27bfff9af033329a9b659e7", "status": "affected", "versionType": "git", "lessThan": "e4d997a1ec1d0dbb72dde35a99fda1850fee6a53" }, { "version": "ecde48a1a6b3256bd49db8780bf37556b157783c", "status": "affected", "versionType": "git", "lessThan": "e18b8236c57fcc67d793bfc866f4bb2581be9f72" }, { "version": "ecde48a1a6b3256bd49db8780bf37556b157783c", "status": "affected", "versionType": "git", "lessThan": "0d26249671171ab759cb4fdce673554a690fa655" }, { "version": "ecde48a1a6b3256bd49db8780bf37556b157783c", "status": "affected", "versionType": "git", "lessThan": "0ef349734a93227b45f65fc50a3311d1cc5f03e9" }, { "version": "ae584726e6eddf6cfbe49b3f4a78b3197716b6f8", "status": "affected", "versionType": "git" }, { "version": "6.12.111", "status": "affected", "versionType": "semver", "lessThan": "6.12.114" }, { "version": "6.14.6", "status": "affected", "versionType": "semver", "lessThan": "6.15" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "6.15", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "6.15" }, { "version": "6.12.114", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.56", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.9", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }