CVE-2026-80656

hfsplus: Add a sanity check for btree node size

HIGH
7.8
CVSS Score
Published: August 28, 2026 at 06:49 AM UTC
Updated: August 29, 2026 at 07:16 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
HIGH7.8
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: hfsplus: Add a sanity check for btree node size Syzbot reported an uninit-value bug in [1] with a corrupted HFS+ image, during the file system mounting process, specifically while loading the catalog, a corrupted node_size value of 1 caused the rec_off argument passed to hfs_bnode_read_u16() (within hfs_bnode_find()) to be excessively large. Consequently, the function failed to return a valid value to initialize the off variable, triggering the bug [1]. Every node starts from BTree node descriptor: struct hfs_bnode_desc. So, the size of node cannot be lesser than that. However, technical specification declares that: "The node size (which is expressed in bytes) must be power of two, from 512 through 32,768, inclusive." Add a check for btree node size base on technical specification. [1] BUG: KMSAN: uninit-value in hfsplus_bnode_find+0x141c/0x1600 fs/hfsplus/bnode.c:584 hfsplus_bnode_find+0x141c/0x1600 fs/hfsplus/bnode.c:584 hfsplus_btree_open+0x169a/0x1e40 fs/hfsplus/btree.c:382 hfsplus_fill_super+0x111f/0x2770 fs/hfsplus/super.c:553 get_tree_bdev_flags+0x6e6/0x920 fs/super.c:1694 get_tree_bdev+0x38/0x50 fs/super.c:1717 hfsplus_get_tree+0x35/0x40 fs/hfsplus/super.c:709 vfs_get_tree+0xb3/0x5d0 fs/super.c:1754 fc_mount fs/namespace.c:1193 [inline]

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

7.1 ≤ v < 7.1.57.1 ≤ v < 7.27.18ad2c6a36ac4328072377906a47ea0bff11e4032
Vendor states this is fixed in 306265eb9384d2c224f1b14d83a29323f0eab6d1 (fixed)
Vendor states this is fixed in 3f95e2661574ff13f099dd13456751933c280628 (fixed)
Vendor states this is fixed in 7.1 (unaffected)
Vendor states this is fixed in 7.1.5 (unaffected)
Vendor states this is fixed in 7.2 (unaffected)

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

CVSS

7.8HIGHLinux
Vector?

Quick Info

StatusRECEIVED

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