CVE-2025-40235
In the Linux kernel, the following vulnerability has been resolved: btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots() If fs_info->super_copy or fs_info->super_for_c…
Overview
CVE-2025-40235 is a known-severity vulnerability. It was published on December 4, 2025.
Technical description
In the Linux kernel, the following vulnerability has been resolved:
btrfs: directly free partially initialized fs_info in btrfs_check_leaked_roots()
If fs_info->super_copy or fs_info->super_for_commit allocated failed in
btrfs_get_tree_subvol(), then no need to call btrfs_free_fs_info().
Otherwise btrfs_check_leaked_roots() would access NULL pointer because
fs_info->allocated_roots had not been initialised.
syzkaller reported the following information:
------------[ cut here ]------------
BUG: unable to handle page fault for address: fffffffffffffbb0
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 64c9067 P4D 64c9067 PUD 64cb067 PMD 0
Oops: Oops: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 1402 Comm: syz.1.35 Not tainted 6.15.8 #4 PREEMPT(lazy)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), (...)
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atom
Remediation
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
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Frequently asked questions
What is CVE-2025-40235?
CVE-2025-40235 is a known-severity vulnerability. It was published on December 4, 2025.
How severe is CVE-2025-40235?
CVSS score information is not yet available for this vulnerability. Check back as the CVE record is updated by NVD analysts.
How do I fix or remediate CVE-2025-40235?
Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.
How can CyberStrike help with CVE-2025-40235?
CyberStrike is an open-source, AI-augmented pentesting engine. Rather than flag a version number, it tests whether an issue like CVE-2025-40235 is actually reachable in your own applications and APIs, then verifies each finding before reporting it. That tells you if the weakness is a real, exploitable risk in your environment or a false positive you can safely deprioritize.