7.8
HIGH
CVE-2025-21887
Linux Kernel OverlayFS Uninitialized Memory Use After Free (UAF) Vulnerability
Description

In the Linux kernel, the following vulnerability has been resolved: ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up The issue was caused by dput(upper) being called before ovl_dentry_update_reval(), while upper->d_flags was still accessed in ovl_dentry_remote(). Move dput(upper) after its last use to prevent use-after-free. BUG: KASAN: slab-use-after-free in ovl_dentry_remote fs/overlayfs/util.c:162 [inline] BUG: KASAN: slab-use-after-free in ovl_dentry_update_reval+0xd2/0xf0 fs/overlayfs/util.c:167 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 ovl_dentry_remote fs/overlayfs/util.c:162 [inline] ovl_dentry_update_reval+0xd2/0xf0 fs/overlayfs/util.c:167 ovl_link_up fs/overlayfs/copy_up.c:610 [inline] ovl_copy_up_one+0x2105/0x3490 fs/overlayfs/copy_up.c:1170 ovl_copy_up_flags+0x18d/0x200 fs/overlayfs/copy_up.c:1223 ovl_rename+0x39e/0x18c0 fs/overlayfs/dir.c:1136 vfs_rename+0xf84/0x20a0 fs/namei.c:4893 ... </TASK>

INFO

Published Date :

March 27, 2025, 3:15 p.m.

Last Modified :

April 1, 2025, 3:45 p.m.

Source :

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Remotely Exploitable :

No

Impact Score :

5.9

Exploitability Score :

1.8
Affected Products

The following products are affected by CVE-2025-21887 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Linux linux_kernel
: Total Affected Vendor : 1 | Products : 1
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2025-21887.

URL Resource
https://git.kernel.org/stable/c/3594aad97e7be2557ca9fa9c931b206b604028c8 Patch
https://git.kernel.org/stable/c/4b49d939b5a79117f939b77cc67efae2694d9799 Patch
https://git.kernel.org/stable/c/60b4b5c1277fc491da9e1e7abab307bfa39c2db7 Patch
https://git.kernel.org/stable/c/64455c8051c3aedc71abb7ec8d47c80301f99f00 Patch
https://git.kernel.org/stable/c/a7c41830ffcd17b2177a95a9b99b270302090c35 Patch
https://git.kernel.org/stable/c/c84e125fff2615b4d9c259e762596134eddd2f27 Patch

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2025-21887 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2025-21887 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Apr. 01, 2025

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.10.188 up to (excluding) 5.11 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.15.121 up to (excluding) 5.15.179 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.1.39 up to (excluding) 6.1.130 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.3.13 up to (excluding) 6.4 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.4.4 up to (excluding) 6.6.81 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.12.18 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.13 up to (excluding) 6.13.6 *cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/3594aad97e7be2557ca9fa9c931b206b604028c8 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/4b49d939b5a79117f939b77cc67efae2694d9799 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/60b4b5c1277fc491da9e1e7abab307bfa39c2db7 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/64455c8051c3aedc71abb7ec8d47c80301f99f00 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/a7c41830ffcd17b2177a95a9b99b270302090c35 Types: Patch
    Added Reference Type kernel.org: https://git.kernel.org/stable/c/c84e125fff2615b4d9c259e762596134eddd2f27 Types: Patch
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Mar. 27, 2025

    Action Type Old Value New Value
    Added CVSS V3.1 AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Added CWE CWE-416
  • New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67

    Mar. 27, 2025

    Action Type Old Value New Value
    Added Description In the Linux kernel, the following vulnerability has been resolved: ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up The issue was caused by dput(upper) being called before ovl_dentry_update_reval(), while upper->d_flags was still accessed in ovl_dentry_remote(). Move dput(upper) after its last use to prevent use-after-free. BUG: KASAN: slab-use-after-free in ovl_dentry_remote fs/overlayfs/util.c:162 [inline] BUG: KASAN: slab-use-after-free in ovl_dentry_update_reval+0xd2/0xf0 fs/overlayfs/util.c:167 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 ovl_dentry_remote fs/overlayfs/util.c:162 [inline] ovl_dentry_update_reval+0xd2/0xf0 fs/overlayfs/util.c:167 ovl_link_up fs/overlayfs/copy_up.c:610 [inline] ovl_copy_up_one+0x2105/0x3490 fs/overlayfs/copy_up.c:1170 ovl_copy_up_flags+0x18d/0x200 fs/overlayfs/copy_up.c:1223 ovl_rename+0x39e/0x18c0 fs/overlayfs/dir.c:1136 vfs_rename+0xf84/0x20a0 fs/namei.c:4893 ... </TASK>
    Added Reference https://git.kernel.org/stable/c/3594aad97e7be2557ca9fa9c931b206b604028c8
    Added Reference https://git.kernel.org/stable/c/4b49d939b5a79117f939b77cc67efae2694d9799
    Added Reference https://git.kernel.org/stable/c/60b4b5c1277fc491da9e1e7abab307bfa39c2db7
    Added Reference https://git.kernel.org/stable/c/64455c8051c3aedc71abb7ec8d47c80301f99f00
    Added Reference https://git.kernel.org/stable/c/a7c41830ffcd17b2177a95a9b99b270302090c35
    Added Reference https://git.kernel.org/stable/c/c84e125fff2615b4d9c259e762596134eddd2f27
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2025-21887 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2025-21887 weaknesses.

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
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