CVE-2025-21887
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>
How to fix
- linux linux_kernel5.11, 5.15.179, 6.1.130, 6.4, 6.6.81, 6.12.18, 6.13.6 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | 5.10.188 ≤ v < 5.11, 5.15.121 ≤ v < 5.15.179, 6.1.39 ≤ v < 6.1.130, 6.3.13 ≤ v < 6.4, 6.4.4 ≤ v < 6.6.81, 6.7 ≤ v < 6.12.18, 6.13 ≤ v < 6.13.6, 6.14 | 5.11, 5.15.179, 6.1.130, 6.4, 6.6.81, 6.12.18, 6.13.6 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.