high 7.0

CVE-2026-46299 json

hfsplus: fix held lock freed on hfsplus_fill_super()

published 2026-06-08 5 mo ago modified 2026-08-05 3 mo ago also EUVD-2026-35165

cvss: 7.0; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.1%; EPSS 0.1% chance of exploitation in 30 days, percentile 0%
public exploits: 0; none known

In the Linux kernel, the following vulnerability has been resolved:

hfsplus_fill_super() calls hfs_find_init() to initialize a search structure, which acquires tree->tree_lock. If the subsequent call to hfsplus_cat_build_key() fails, the function jumps to the out_put_root error label without releasing the lock. The later cleanup path then frees the tree data structure with the lock still held, triggering a held lock freed warning.

Fix this by adding the missing hfs_find_exit(&fd) call before jumping to the out_put_root error label. This ensures that tree->tree_lock is properly released on the error path.

The bug was originally detected on v6.13-rc1 using an experimental static analysis tool we are developing, and we have verified that the issue persists in the latest mainline kernel. The tool is specifically designed to detect memory management issues. It is currently under active development and not yet publicly available.

We confirmed the bug by runtime testing under QEMU with x86_64 defconfig, lockdep enabled, and CONFIG_HFSPLUS_FS=y. To trigger the error path, we used GDB to dynamically shrink the max_unistr_len parameter to 1 before hfsplus_asc2uni() is called. This forces hfsplus_asc2uni() to naturally return -ENAMETOOLONG, which propagates to hfsplus_cat_build_key() and exercises the faulty error path. The following warning was observed during mount:

========================= WARNING: held lock freed! 7.0.0-rc3-00016-gb4f0dd314b39 #4 Not tainted ------------------------- mount/174 is freeing memory ffff888103f92000-ffff888103f92fff, with a lock still held there! ffff888103f920b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x1e0 2 locks held by mount/174: #0: ffff888103f960e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.constprop.0+0x167/0xa40 #1: ffff888103f920b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x154/0x1e0

stack backtrace: CPU: 2 UID: 0 PID: 174 Comm: mount Not tainted 7.0.0-rc3-00016-gb4f0dd314b39 #4 PREEMPT(lazy) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x82/0xd0 debug_check_no_locks_freed+0x13a/0x180 kfree+0x16b/0x510 ? hfsplus_fill_super+0xcb4/0x18a0 hfsplus_fill_super+0xcb4/0x18a0 ? __pfx_hfsplus_fill_super+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? bdev_open+0x65f/0xc30 ? srso_return_thunk+0x5/0x5f ? pointer+0x4ce/0xbf0 ? trace_contention_end+0x11c/0x150 ? __pfx_pointer+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? bdev_open+0x79b/0xc30 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? vsnprintf+0x6da/0x1270 ? srso_return_thunk+0x5/0x5f ? __mutex_unlock_slowpath+0x157/0x740 ? __pfx_vsnprintf+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? mark_held_locks+0x49/0x80 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? irqentry_exit+0x17b/0x5e0 ? trace_irq_disable.constprop.0+0x116/0x150 ? __pfx_hfsplus_fill_super+0x10/0x10 ? __pfx_hfsplus_fill_super+0x10/0x10 get_tree_bdev_flags+0x302/0x580 ? __pfx_get_tree_bdev_flags+0x10/0x10 ? vfs_parse_fs_qstr+0x129/0x1a0 ? __pfx_vfs_parse_fs_qstr+0x3/0x10 vfs_get_tree+0x89/0x320 fc_mount+0x10/0x1d0 path_mount+0x5c5/0x21c0 ? __pfx_path_mount+0x10/0x10 ? trace_irq_enable.constprop.0+0x116/0x150 ? trace_irq_enable.constprop.0+0x116/0x150 ? srso_return_thunk+0x5/0x5f ? srso_return_thunk+0x5/0x5f ? kmem_cache_free+0x307/0x540 ? user_path_at+0x51/0x60 ? __x64_sys_mount+0x212/0x280 ? srso_return_thunk+0x5/0x5f __x64_sys_mount+0x212/0x280 ? __pfx___x64_sys_mount+0x10/0x10 ? srso_return_thunk+0x5/0x5f ? trace_irq_enable.constprop.0+0x116/0x150 ? srso_return_thunk+0x5/0x5f do_syscall_64+0x111/0x680 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffacad55eae Code: 48 8b 0d 85 1f 0f 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 49 89 ca b8 a5 00 00 8 RSP: 002b ---truncated---

Patch / fix

fixed in 1 distros 5 links 8

Linux Linux 5.10.259, 5.15.210, 6.1.176, 6.6.140, 6.12.88, 6.18.30, 7.0.7, 7.1

debian ubuntu suse opensuse azure linux

linux Debian 12 6.1.176-1
linux Debian 13 6.12.88-1
linux Debian 14 7.0.7-1

debian advisories DEBIAN-CVE-2026-46299

linux Ubuntu 22.04 LTS 5.15.0-198.208
linux Ubuntu 24.04 LTS 6.8.0-136.136
linux Ubuntu 26.04 LTS 7.0.0-28.28
linux-aws Ubuntu 22.04 LTS 5.15.0-1117.124
linux-aws Ubuntu 24.04 LTS 6.8.0-1061.64
linux-aws Ubuntu 26.04 LTS 7.0.0-1009.9
linux-gcp Ubuntu 22.04 LTS 5.15.0-1118.128
linux-gcp Ubuntu 24.04 LTS 6.8.0-1064.72

ubuntu advisories UBUNTU-CVE-2026-46299

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

kernel-syms SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 4.12.14-122.320.1
kernel-source SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS 4.12.14-122.320.1
kernel-default SLES LTSS Extended Security 12 SP5, SLES 12 SP5-LTSS, SLE Live Patching 12 SP5 4.12.14-122.320.1
kgraft-patch-SLE12-SP5_Update_85 SLE Live Patching 12 SP5 1-8.3.1

suse advisories SUSE-SU-2026:2914-1

kernel-source openSUSE Tumbleweed 7.0.12-1.1

opensuse advisories openSUSE-SU-2026:11014-1

kernel Azure Linux 3.0 6.6.141.1-1

azure linux advisories AZL-89661

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-46299 updated 2026-11-06 cvss 5.5

kernel: hfsplus: fix held lock freed on hfsplus_fill_super()

Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more
affected: no fix planned “Out of support scope”
Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.09% chance of exploitation in the next 30 days, higher than 0% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	7.0	CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

Linux Linux

Classification

Weakness

CWE-667 Improper Locking

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2026-46299
NVD CVE-2026-46299

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary