CVE-2025-37904

What it is

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix the inode leak in btrfs_iget() [BUG] There is a bug report that a syzbot reproducer can lead to the following busy inode at unmount time: BTRFS info (device loop1): last unmount of filesystem 1680000e-3c1e-4c46-84b6-56bd3909af50 VFS: Busy inodes after unmount of loop1 (btrfs) ------------[ cut here ]------------ kernel BUG at fs/super.c:650! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 0 UID: 0 PID: 48168 Comm: syz-executor Not tainted 6.15.0-rc2-00471-g119009db2674 #2 PREEMPT(full) Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:generic_shutdown_super+0x2e9/0x390 fs/super.c:650 Call Trace: <TASK> kill_anon_super+0x3a/0x60 fs/super.c:1237 btrfs_kill_super+0x3b/0x50 fs/btrfs/super.c:2099 deactivate_locked_super+0xbe/0x1a0 fs/super.c:473 deactivate_super fs/super.c:506 [inline] deactivate_super+0xe2/0x100 fs/super.c:502 cleanup_mnt+0x21f/0x440 fs/namespace.c:1435 task_work_run+0x14d/0x240 kernel/task_work.c:227 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x269/0x290 kernel/entry/common.c:218 do_syscall_64+0xd4/0x250 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f </TASK> [CAUSE] When btrfs_alloc_path() failed, btrfs_iget() directly returned without releasing the inode already allocated by btrfs_iget_locked(). This results the above busy inode and trigger the kernel BUG. [FIX] Fix it by calling iget_failed() if btrfs_alloc_path() failed. If we hit error inside btrfs_read_locked_inode(), it will properly call iget_failed(), so nothing to worry about. Although the iget_failed() cleanup inside btrfs_read_locked_inode() is a break of the normal error handling scheme, let's fix the obvious bug and backport first, then rework the error handling later.

At a glance

Exploitability

Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.

Exploit odds

0.2% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2025-05-20 16:15 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-06-17 09:15 UTC Last updatedMost recent change to the record

Why it ranks here

• Exploited in the wild: no, CISA does not list it.
• Exploit odds: 0.2% in the next 30 days (EPSS).
• Severity: 5.5 MEDIUM (CVSS).
• Fix: a patch or advisory is linked.

Details

Published

2025-05-20 16:15 UTC

Last modified

2026-06-17 09:15 UTC

Exploit probability

0.2% · EPSS, next 30 days

Weakness

CWE-401

Record status

Analyzed

Affected

• Linux Kernel < 6.14.6
• Linux Kernel 6.15

Attack profile CVSS 3.1 · 5.5

Attack vector

Local

Complexity

Low

Privileges needed

Low

User interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Is it in your code?

Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.

Read https://cve-list.com/agent/cve/CVE-2025-37904.md and follow it. Check whether this project is affected by CVE-2025-37904. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.

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