{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-64567", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.797Z", "datePublished": "2026-08-05T08:08:06.015Z", "dateUpdated": "2026-08-05T08:08:06.015Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T08:08:06.015Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: reject free space cache with more entries than pages\n\nWhen loading a v1 free space cache, __load_free_space_cache() takes\nnum_entries and num_bitmaps straight from the on-disk\nbtrfs_free_space_header. That header is stored in the tree_root under a key\nwith type 0, which the tree-checker has no case for, so neither count is\nvalidated before the load trusts it.\n\nThe load loops num_entries times and maps the next page whenever the current\none runs out, going through io_ctl_check_crc() -> io_ctl_map_page(), which\ndoes io_ctl->pages[io_ctl->index++]. But pages[] is allocated in\nio_ctl_init() from the cache inode's i_size, not from num_entries:\n\n\tnum_pages = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE);\n\tio_ctl->pages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);\n\nSo if num_entries claims more records than the pages can hold, io_ctl->index\nruns off the end of pages[]. The write side never hits this because\nio_ctl_add_entry() and io_ctl_add_bitmap() both stop once\nio_ctl->index >= io_ctl->num_pages; the read side just never had the same\ncheck.\n\nTo trigger it, take a clean cache (num_entries = <N> here), set num_entries\nin the header to 0x10000, and fix up the leaf checksum so it still passes\nthe tree-checker. The cache inode has i_size = 65536, so num_pages is 16 and\npages[] is a 16-pointer (kmalloc-128) array. The load now tries to read\n65536 entries, io_ctl->index walks up to 16, and pages[16] is read past the\narray:\n\n BUG: KASAN: slab-out-of-bounds in io_ctl_check_crc (fs/btrfs/free-space-cache.c:420 fs/btrfs/free-space-cache.c:565)\n Read of size 8 at addr ffff88800c833a80 by task kworker/u8:3/58\n io_ctl_check_crc (fs/btrfs/free-space-cache.c:420 fs/btrfs/free-space-cache.c:565)\n __load_free_space_cache (fs/btrfs/free-space-cache.c:655 fs/btrfs/free-space-cache.c:820)\n load_free_space_cache (fs/btrfs/free-space-cache.c:1017)\n caching_thread (fs/btrfs/block-group.c:880)\n btrfs_work_helper (fs/btrfs/async-thread.c:312)\n process_one_work\n worker_thread\n kthread\n ret_from_fork\n\nfree-space-cache.c:420 is io_ctl_map_page(), inlined into io_ctl_check_crc()\nat line 565, which is why that is the frame KASAN names. The out-of-bounds\nslot is then treated as a struct page and handed to crc32c(), so the bad\nread turns into a GP fault.\n\nAdd the missing check to io_ctl_check_crc(), which is where both the entry\nloop and the bitmap loop end up. When num_entries is too large the load now\nfails like any corrupt cache: __load_free_space_cache() drops it and rebuilds\nthe free space from the extent tree, so a valid cache is never rejected."}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/btrfs/free-space-cache.c"], "versions": [{"version": "5b0e95bf607ddd59b39f52d3d55e6581c817b530", "lessThan": "33878ba25e2638bc0c61623d7a05c9ca2b74c039", "status": "affected", "versionType": "git"}, {"version": "5b0e95bf607ddd59b39f52d3d55e6581c817b530", "lessThan": "404a0b986e0b6e79738fdf1f0ebbbc43b9acd2a2", "status": "affected", "versionType": "git"}, {"version": "5b0e95bf607ddd59b39f52d3d55e6581c817b530", "lessThan": "5e1b2ca6b34939e70fb0785e8222b53cf060016f", "status": "affected", "versionType": "git"}, {"version": "5b0e95bf607ddd59b39f52d3d55e6581c817b530", "lessThan": "f9fef131fa3f59b857217f522fa5ea430d1b707c", "status": "affected", "versionType": "git"}, {"version": "5b0e95bf607ddd59b39f52d3d55e6581c817b530", "lessThan": "a2d8d5647ed854e38f941741aea45b9eb15a6350", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/btrfs/free-space-cache.c"], "versions": [{"version": "3.2", "status": "affected"}, {"version": "0", "lessThan": "3.2", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.101", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2-rc4", "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": "3.2", "versionEndExcluding": "6.6.148"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.12.101"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "6.18.42"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "7.1.6"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.2", "versionEndExcluding": "7.2-rc4"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/33878ba25e2638bc0c61623d7a05c9ca2b74c039"}, {"url": "https://git.kernel.org/stable/c/404a0b986e0b6e79738fdf1f0ebbbc43b9acd2a2"}, {"url": "https://git.kernel.org/stable/c/5e1b2ca6b34939e70fb0785e8222b53cf060016f"}, {"url": "https://git.kernel.org/stable/c/f9fef131fa3f59b857217f522fa5ea430d1b707c"}, {"url": "https://git.kernel.org/stable/c/a2d8d5647ed854e38f941741aea45b9eb15a6350"}], "title": "btrfs: reject free space cache with more entries than pages", "x_generator": {"engine": "bippy-1.2.0"}}}}

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{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b0e95bf607ddd59b39f52d3d55e6581c817b530,33878ba25e2638bc0c61623d7a05c9ca2b74c039)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b0e95bf607ddd59b39f52d3d55e6581c817b530,404a0b986e0b6e79738fdf1f0ebbbc43b9acd2a2)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b0e95bf607ddd59b39f52d3d55e6581c817b530,5e1b2ca6b34939e70fb0785e8222b53cf060016f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b0e95bf607ddd59b39f52d3d55e6581c817b530,f9fef131fa3f59b857217f522fa5ea430d1b707c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[5b0e95bf607ddd59b39f52d3d55e6581c817b530,a2d8d5647ed854e38f941741aea45b9eb15a6350)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "3.2"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,3.2)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.148,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.101,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.42,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.6,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc4,*)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-05T09:30:11.490994+00:00", "updated": "2026-08-05T10:00:03.603949+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}