{"id":"CVE-2026-80656","summary":"hfsplus: Add a sanity check for btree node size","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nhfsplus: Add a sanity check for btree node size\n\nSyzbot reported an uninit-value bug in [1] with a corrupted HFS+ image,\nduring the file system mounting process, specifically while loading the\ncatalog, a corrupted node_size value of 1 caused the rec_off argument\npassed to hfs_bnode_read_u16() (within hfs_bnode_find()) to be excessively\nlarge. Consequently, the function failed to return a valid value to\ninitialize the off variable, triggering the bug [1].\n\nEvery node starts from BTree node descriptor: struct hfs_bnode_desc.\nSo, the size of node cannot be lesser than that. However, technical\nspecification declares that: \"The node size (which is expressed in bytes)\nmust be power of two, from 512 through 32,768, inclusive.\" Add a check\nfor btree node size base on technical specification.\n\n[1]\nBUG: KMSAN: uninit-value in hfsplus_bnode_find+0x141c/0x1600 fs/hfsplus/bnode.c:584\n hfsplus_bnode_find+0x141c/0x1600 fs/hfsplus/bnode.c:584\n hfsplus_btree_open+0x169a/0x1e40 fs/hfsplus/btree.c:382\n hfsplus_fill_super+0x111f/0x2770 fs/hfsplus/super.c:553\n get_tree_bdev_flags+0x6e6/0x920 fs/super.c:1694\n get_tree_bdev+0x38/0x50 fs/super.c:1717\n hfsplus_get_tree+0x35/0x40 fs/hfsplus/super.c:709\n vfs_get_tree+0xb3/0x5d0 fs/super.c:1754\n fc_mount fs/namespace.c:1193 [inline]","modified":"2026-08-30T03:48:20.934499160Z","published":"2026-08-28T06:49:02.596Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80656.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/306265eb9384d2c224f1b14d83a29323f0eab6d1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3f95e2661574ff13f099dd13456751933c280628"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80656.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-80656"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8ad2c6a36ac4328072377906a47ea0bff11e4032"},{"fixed":"306265eb9384d2c224f1b14d83a29323f0eab6d1"},{"fixed":"3f95e2661574ff13f099dd13456751933c280628"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80656.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"7.1.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80656.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}