Cloudanix VulnDB

CVE-2025-38716

None

CVSS

—

EPSS

0.1%

Published

Sep 4, 2025

CISA due date

—

Cloudanix analysis

Schedule a fix SSVC: Track

A bug in the Linux kernel's handling of certain older disk formats can cause the whole system to crash if someone plugs in or mounts a specially made disk image.

Exploitation
Local Privilege
Attacker needs
Local User
Complexity
Low
Impact
Denial Of Service
Component
OS kernel
Class
Memory Corruption
Remediation
Upgrade
Effort
Medium
Patch risk
Low

What it actually does

Null pointer dereference in hfs_find_init() triggered when the HFS tree pointer is NULL, resulting in a general protection fault during extent reading and btree operations on mount.

Why it matters to the business

Local denial of service via system crash when untrusted HFS volumes are mounted; high impact in container and VM environments that process external disk images, though the flaw is over a year old with no observed exploitation.

How an attack unfolds

An attacker prepares a malformed HFS filesystem image that leaves the tree pointer NULL, then causes the kernel to mount it through normal VFS paths, leading to the crash in hfs_find_init during btree initialization and extent lookup.

How to fix it

Apply the upstream fix commit 4f032979b63ad52e08aadf0faeac34ed35133ec0 or later stable kernel; for MinimOS packages update openjdk-11 variants to 11.0.28-r0.

How to confirm the fix worked

Confirm kernel version contains the referenced commit; attempt to mount a test HFS image that previously triggered the fault and verify no oops occurs.

Typical attack path

  1. Craft a malicious HFS volume with invalid btree metadata
  2. Trigger mount via VFS or user-space tools on a Linux system
  3. Kernel executes hfs_fill_super -> hfs_mdb_get -> hfs_btree_open -> hfs_get_block -> hfs_ext_read_extent -> hfs_find_init
  4. NULL tree pointer causes GPF and kernel oops

How to detect it

Review kernel logs for general protection faults referencing hfs_find_init, hfs_ext_read_extent, or hfs_btree_open during mount operations; correlate with mount activity of HFS volumes.

What your security team should do

  • Prioritize kernel updates on systems that mount external or untrusted HFS volumes
  • Restrict HFS filesystem mounting via mount options or module blacklisting where HFS is unnecessary
  • Monitor for related kernel crashes in logs even though EPSS remains low and no KEV entry exists

The record

In the Linux kernel, the following vulnerability has been resolved: hfs: fix general protection fault in hfs_find_init() The hfs_find_init() method can trigger the crash if tree pointer is NULL: [ 45.746290][ T9787] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KAI [ 45.747287][ T9787] KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047] [ 45.748716][ T9787] CPU: 2 UID: 0 PID: 9787 Comm: repro Not tainted 6.16.0-rc3 #10 PREEMPT(full) [ 45.750250][ T9787] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 [ 45.751983][ T9787] RIP: 0010:hfs_find_init+0x86/0x230 [ 45.752834][ T9787] Code: c1 ea 03 80 3c 02 00 0f 85 9a 01 00 00 4c 8d 6b 40 48 c7 45 18 00 00 00 00 48 b8 00 00 00 00 00 fc [ 45.755574][ T9787] RSP: 0018:ffffc90015157668 EFLAGS: 00010202 [ 45.756432][ T9787] RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff819a4d09 [ 45.757457][ T9787] RDX: 0000000000000008 RSI: ffffffff819acd3a RDI: ffffc900151576e8 [ 45.758282][ T9787] RBP: ffffc900151576d0 R08: 0000000000000005 R09: 0000000000000000 [ 45.758943][ T9787] R10: 0000000080000000 R11: 0000000000000001 R12: 0000000000000004 [ 45.759619][ T9787] R13: 0000000000000040 R14: ffff88802c50814a R15: 0000000000000000 [ 45.760293][ T9787] FS: 00007ffb72734540(0000) GS:ffff8880cec64000(0000) knlGS:0000000000000000 [ 45.761050][ T9787] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 45.761606][ T9787] CR2: 00007f9bd8225000 CR3: 000000010979a000 CR4: 00000000000006f0 [ 45.762286][ T9787] Call Trace: [ 45.762570][ T9787] <TASK> [ 45.762824][ T9787] hfs_ext_read_extent+0x190/0x9d0 [ 45.763269][ T9787] ? submit_bio_noacct_nocheck+0x2dd/0xce0 [ 45.763766][ T9787] ? __pfx_hfs_ext_read_extent+0x10/0x10 [ 45.764250][ T9787] hfs_get_block+0x55f/0x830 [ 45.764646][ T9787] block_read_full_folio+0x36d/0x850 [ 45.765105][ T9787] ? __pfx_hfs_get_block+0x10/0x10 [ 45.765541][ T9787] ? const_folio_flags+0x5b/0x100 [ 45.765972][ T9787] ? __pfx_hfs_read_folio+0x10/0x10 [ 45.766415][ T9787] filemap_read_folio+0xbe/0x290 [ 45.766840][ T9787] ? __pfx_filemap_read_folio+0x10/0x10 [ 45.767325][ T9787] ? __filemap_get_folio+0x32b/0xbf0 [ 45.767780][ T9787] do_read_cache_folio+0x263/0x5c0 [ 45.768223][ T9787] ? __pfx_hfs_read_folio+0x10/0x10 [ 45.768666][ T9787] read_cache_page+0x5b/0x160 [ 45.769070][ T9787] hfs_btree_open+0x491/0x1740 [ 45.769481][ T9787] hfs_mdb_get+0x15e2/0x1fb0 [ 45.769877][ T9787] ? __pfx_hfs_mdb_get+0x10/0x10 [ 45.770316][ T9787] ? find_held_lock+0x2b/0x80 [ 45.770731][ T9787] ? lockdep_init_map_type+0x5c/0x280 [ 45.771200][ T9787] ? lockdep_init_map_type+0x5c/0x280 [ 45.771674][ T9787] hfs_fill_super+0x38e/0x720 [ 45.772092][ T9787] ? __pfx_hfs_fill_super+0x10/0x10 [ 45.772549][ T9787] ? snprintf+0xbe/0x100 [ 45.772931][ T9787] ? __pfx_snprintf+0x10/0x10 [ 45.773350][ T9787] ? do_raw_spin_lock+0x129/0x2b0 [ 45.773796][ T9787] ? find_held_lock+0x2b/0x80 [ 45.774215][ T9787] ? set_blocksize+0x40a/0x510 [ 45.774636][ T9787] ? sb_set_blocksize+0x176/0x1d0 [ 45.775087][ T9787] ? setup_bdev_super+0x369/0x730 [ 45.775533][ T9787] get_tree_bdev_flags+0x384/0x620 [ 45.775985][ T9787] ? __pfx_hfs_fill_super+0x10/0x10 [ 45.776453][ T9787] ? __pfx_get_tree_bdev_flags+0x10/0x10 [ 45.776950][ T9787] ? bpf_lsm_capable+0x9/0x10 [ 45.777365][ T9787] ? security_capable+0x80/0x260 [ 45.777803][ T9787] vfs_get_tree+0x8e/0x340 [ 45.778203][ T9787] path_mount+0x13de/0x2010 [ 45.778604][ T9787] ? kmem_cache_free+0x2b0/0x4c0 [ 45.779052][ T9787] ? __pfx_path_mount+0x10/0x10 [ 45.779480][ T9787] ? getname_flags.part.0+0x1c5/0x550 [ 45.779954][ T9787] ? putname+0x154/0x1a0 [ 45.780335][ T9787] __x64_sys_mount+0x27b/0x300 [ 45.780758][ T9787] ? __pfx___x64_sys_mount+0x10/0x10 [ 45.781232][ T9787] ---truncated---

Affected packages

Ecosystem Package Introduced Fixed
Debian:11 linux 0 No fix
Debian:12 linux 0 No fix
Debian:13 linux 0 6.12.43-1
Debian:14 linux 0 6.16.3-1
Linux Kernel 0 6.6.103
Linux Kernel 3.2.0 6.6.103
Mageia:9 kernel 0 6.6.105-1.mga9
Mageia:9 kernel-linus 0 6.6.105-1.mga9
Mageia:9 kmod-virtualbox 0 7.1.10-10.mga9
Mageia:9 kmod-xtables-addons 0 3.24-86.mga9
Mageia:9 mageia-repos 0 9-4.mga9
Mageia:9 meta-task 0 9-4.mga9

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