{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2026-64567 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2026-64567 is a high-severity memory corruption vulnerability in Linux, published on 5 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2026-64567 and fix it if it is affected.\n\nWhat it is: CVE-2026-64567 is a high-severity memory corruption vulnerability in Linux, published on 5 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2026-64567 in the wild and no public exploit code.\n\nAffected product: Linux. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2026-64567/ (Markdown: https://insights.sbomify.com/CVE-2026-64567/index.md)","id":"CVE-2026-64567","markdown":"https://insights.sbomify.com/CVE-2026-64567/index.md","name":"CVE-2026-64567","record":{"aliases":["AZL-94482","BELL-CVE-2026-64567","DEBIAN-CVE-2026-64567","GHSA-834p-x3hc-j46g","UBUNTU-CVE-2026-64567"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel filesystem","requires_auth":"low_privilege","summary":"A local attacker with mount privileges can trigger a slab-out-of-bounds read in the btrfs filesystem by crafting a malicious free space cache, potentially causing a kernel crash or code execution.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"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() -\u003e io_ctl_map_page(), which\ndoes io_ctl-\u003epages[io_ctl-\u003eindex++]. 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-\u003epages = kcalloc(num_pages, sizeof(struct page *), GFP_NOFS);\n\nSo if num_entries claims more records than the pages can hold, io_ctl-\u003eindex\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-\u003eindex \u003e= io_ctl-\u003enum_pages; the read side just never had the same\ncheck.\n\nTo trigger it, take a clean cache (num_entries = \u003cN\u003e 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-\u003eindex 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.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"btrfs: reject free space cache with more entries than pages","id":"CVE-2026-64567","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"memory_corruption","year":"2026"},"n_packages":0,"n_references":8,"next":{"headline":"wifi: mac80211: fix unsol_bcast_probe_resp double free on alloc failure","id":"CVE-2026-64568"},"packages":[],"prev":{"headline":"xfrm: iptfs: propagate SKBFL_SHARED_FRAG in iptfs_skb_add_frags()","id":"CVE-2026-64566"},"products":["Linux"],"published":"2026-08-05","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-10-19","vendors":["Linux"]},"summary":"A local attacker with mount privileges can trigger a slab-out-of-bounds read in the btrfs filesystem by crafting a malicious free space cache, potentially causing a kernel crash or code execution.","url":"https://insights.sbomify.com/CVE-2026-64567/"}