CVE-2025-21887

Advisory lineage Upstream: 0 Downstream: 41
Modified
Published: 27 Mar 2025, 14:57
Last modified:23 May 2026, 15:57

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.01% LOW
0% probability -0.02%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

27 Mar 2025, 14:57
Published
Vulnerability first disclosed
23 May 2026, 15:57
Last Modified
Vulnerability information updated

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>

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.01%• Percentile: 3%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • linux•linux

    ≥ 714ba10a6dd19752a349e59aa875f3288ccb59b9, < f77618291836168eca99e89cd175256f928f5e64 | ≥ 62f29ca45f832e281fc14966ac25f6ff3bd121ca, < 4b49d939b5a79117f939b77cc67efae2694d9799 | ≥ e4f2a1feebb3f209a0fca82aa53507a5b8be4d53, < a7c41830ffcd17b2177a95a9b99b270302090c35 | ≥ b07d5cc93e1b28df47a72c519d09d0a836043613, < 64455c8051c3aedc71abb7ec8d47c80301f99f00 | ≥ b07d5cc93e1b28df47a72c519d09d0a836043613, < 3594aad97e7be2557ca9fa9c931b206b604028c8 | ≥ b07d5cc93e1b28df47a72c519d09d0a836043613, < 60b4b5c1277fc491da9e1e7abab307bfa39c2db7 | ≥ b07d5cc93e1b28df47a72c519d09d0a836043613, < c84e125fff2615b4d9c259e762596134eddd2f27 | 33ab4dd6202f359558a0a2678b94d1b9994c17e5 | 1ecdc55e5cd9f70f8d7513802971d4cffb9f77af | ≥ 5.10.188, < 5.10.247 | ≥ 5.15.121, < 5.15.179 | ≥ 6.1.39, < 6.1.130 | ≥ 6.3.13, < 6.4 | ≥ 6.4.4, < 6.5 | 6.5

  • linux•linux_kernel

    ≥ 5.10.188, < 5.11 | ≥ 5.15.121, < 5.15.179 | ≥ 6.1.39, < 6.1.130 | ≥ 6.3.13, < 6.4 | ≥ 6.4.4, < 6.6.81 | ≥ 6.7, < 6.12.18 | ≥ 6.13, < 6.13.6 | 6.14:rc1 | 6.14:rc2 | 6.14:rc3 | 6.14:rc4

References (8)