N/A - CVE-2025-21887

Executive Summary

Informations
Name	CVE-2025-21887	First vendor Publication	2025-03-27
Vendor	Cve	Last vendor Modification	2025-03-27

Security-Database Scoring CVSS v3

Cvss vector : N/A
Overall CVSS Score	NA
Base Score	NA	Environmental Score	NA
impact SubScore	NA	Temporal Score	NA
Exploitabality Sub Score	NA

Calculate full CVSS 3.0 Vectors scores

Security-Database Scoring CVSS v2

Cvss vector :
Cvss Base Score	N/A	Attack Range	N/A
Cvss Impact Score	N/A	Attack Complexity	N/A
Cvss Expoit Score	N/A	Authentication	N/A
Calculate full CVSS 2.0 Vectors scores

Detail

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:

__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 ...