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High · 7.8 CVE-2026-80656 EUVD-2026-67532GHSA-prqf-3j7q-v843

hfsplus: Add a sanity check for btree node size

Published Aug 28, 2026 · Updated Aug 29, 2026 · Assigned by Linux

Vendor: Linux Product: Linux Package: linux Package: linux-allwinner-5.19 Package: linux-aws-5.0 Package: linux-aws-5.11 Package: linux-aws-5.13 Package: linux-aws-5.19 Package: linux-aws-5.3 Package: linux-aws-5.8 Package: linux-aws-6.14 Package: linux-aws-6.17 Package: linux-aws-6.2 Package: linux-aws-6.5 Package: linux-azure Package: linux-azure-5.11 Package: linux-azure-5.13 Package: linux-azure-5.19 Package: linux-azure-5.3 Package: linux-azure-5.8 Package: linux-azure-6.11 Package: linux-azure-6.14 Package: linux-azure-6.17 Package: linux-azure-6.2 Package: linux-azure-6.5 Package: linux-azure-edge Package: linux-azure-fde Package: linux-azure-fde-5.19 Package: linux-azure-fde-6.14 Package: linux-azure-fde-6.17 Package: linux-azure-fde-6.2 Package: linux-azure-nvidia-6.14 Package: linux-gcp Package: linux-gcp-5.11 Package: linux-gcp-5.13 Package: linux-gcp-5.19 Package: linux-gcp-5.3 Package: linux-gcp-5.8 Package: linux-gcp-6.11 Package: linux-gcp-6.14 Package: linux-gcp-6.17 Package: linux-gcp-6.2 Package: linux-gcp-6.5 Package: linux-gke Package: linux-gke-4.15 Package: linux-gke-5.15 Package: linux-gke-5.4 Package: linux-gkeop Package: linux-gkeop-5.15 Package: linux-gkeop-5.4 Package: linux-hwe Package: linux-hwe-5.11 Package: linux-hwe-5.13 Package: linux-hwe-5.19 Package: linux-hwe-5.8 Package: linux-hwe-6.11 Package: linux-hwe-6.14 Package: linux-hwe-6.2 Package: linux-hwe-6.5 Package: linux-hwe-edge Package: linux-intel-5.13 Package: linux-intel-iot-realtime Package: linux-lowlatency-hwe-5.19 Package: linux-lowlatency-hwe-6.11 Package: linux-lowlatency-hwe-6.2 Package: linux-lowlatency-hwe-6.5 Package: linux-nvidia-6.11 Package: linux-nvidia-6.2 Package: linux-nvidia-6.5 Package: linux-oem Package: linux-oem-5.10 Package: linux-oem-5.13 Package: linux-oem-5.14 Package: linux-oem-5.17 Package: linux-oem-5.6 Package: linux-oem-6.0 Package: linux-oem-6.1 Package: linux-oem-6.11 Package: linux-oem-6.14 Package: linux-oem-6.5 Package: linux-oem-6.8 Package: linux-oracle-5.0 Package: linux-oracle-5.11 Package: linux-oracle-5.13 Package: linux-oracle-5.3 Package: linux-oracle-5.8 Package: linux-oracle-6.14 Package: linux-oracle-6.17 Package: linux-oracle-6.5 Package: linux-raspi-realtime Package: linux-raspi2 Package: linux-realtime Package: linux-realtime-6.14 Package: linux-realtime-6.17 Package: linux-riscv Package: linux-riscv-5.11 Package: linux-riscv-5.19 Package: linux-riscv-5.8 Package: linux-riscv-6.14 Package: linux-riscv-6.17 Package: linux-riscv-6.5 Package: linux-starfive-5.19 Package: linux-starfive-6.2 Package: linux-starfive-6.5 Package: linux-vmware Platform: Linux Ecosystem: Debian Ecosystem: Ubuntu

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 products

VendorProductAffectedFixed
Linux Linux 7.1 7.1.5

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 linux 7.1.5-1 —
ReleasePackageFixed inAdvisory
Ubuntu 24.04 LTS linux-riscv +24 No fix yet —
Ubuntu 22.04 LTS linux-riscv +32 No fix yet —
Ubuntu 20.04 LTS linux-gke +28 No fix yet —
Ubuntu 18.04 LTS linux-gcp +14 No fix yet —
Ubuntu 16.04 LTS linux-hwe-edge No fix yet —
Show 1 more (older releases, extended support, other products)
ReleasePackageFixed inAdvisory
Ubuntu Pro Realtime 24.04 LTS linux-realtime-6.14 +1 No fix yet —

Advisories 1

References