Answer in brief
CVE-2025-21887 records a High severity (CVSS 7.8) vulnerability in ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2025-21887 records a High severity (CVSS 7.8) vulnerability in ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 6.5 | Not reported |
| Linux/Linuxgeneric | >=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 | f77618291836168eca99e89cd175256f928f5e64, 4b49d939b5a79117f939b77cc67efae2694d9799, a7c41830ffcd17b2177a95a9b99b270302090c35, 64455c8051c3aedc71abb7ec8d47c80301f99f00, 3594aad97e7be2557ca9fa9c931b206b604028c8, 60b4b5c1277fc491da9e1e7abab307bfa39c2db7, c84e125fff2615b4d9c259e762596134eddd2f27, 5.10.247, 5.15.179, 6.1.130, 6.4, 6.5 |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Mar 27, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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>
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic), Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (generic), Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (generic) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | 6.5 | Not reported |
| Linux/Linuxgeneric | >=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 | f77618291836168eca99e89cd175256f928f5e64, 4b49d939b5a79117f939b77cc67efae2694d9799, a7c41830ffcd17b2177a95a9b99b270302090c35, 64455c8051c3aedc71abb7ec8d47c80301f99f00, 3594aad97e7be2557ca9fa9c931b206b604028c8, 60b4b5c1277fc491da9e1e7abab307bfa39c2db7, c84e125fff2615b4d9c259e762596134eddd2f27, 5.10.247, 5.15.179, 6.1.130, 6.4, 6.5 |
| Siemens/SIMATIC S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIMATIC S7-1500 CPU 1518F-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
| Siemens/SIPLUS S7-1500 CPU 1518-4 PN/DP MFPgeneric | >=V3.1.6 <* | * |
Published upstream
Mar 27, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 14, 2026
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>
Quoted source text, attributed separately from HOL analysis.