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TI-2025-15837 Aliases CVE-2025-21887GHSA-vjwm-w9rc-f4cc

ovl: fix UAF in ovl_dentry_update_reval by moving dput() in ovl_link_up

Priority LOW 35CWE-416Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Code execution
Confidentiality · integrity · availability
High · High · High
Fix status
Partial Red Hat: 15 fixed, 1 without a fix

Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.

Summary

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>

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00223 12th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.10.247, 5.15.179, 6.1.130 +6Red Hat: 3 advisoriesRed Hat: 15 fixed, 1 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Total

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux5.10.188 to before 5.10.247; 5.15.121 to before 5.15.179; 6.1.39 to before 6.1.130; 6.3.13 to before 6.4; 6.4.4 to before 6.55.10.247, 5.15.179, 6.1.130, 6.4, 6.5Patch availableCNA
LinuxLinux6.5 and later5.10.247, 5.15.179, 6.1.130, 6.6.81, 6.12.18, 6.13.6, 6.14Patch availableCNA
  • Linux VendorLinux Affected 5.10.188 to before 5.10.247; 5.15.121 to before 5.15.179; 6.1.39 to before 6.1.130; 6.3.13 to before 6.4; 6.4.4 to before 6.5 Fixed in 5.10.247, 5.15.179, 6.1.130, 6.4, 6.5 Patch available CNA
  • Linux VendorLinux Affected 6.5 and later Fixed in 5.10.247, 5.15.179, 6.1.130, 6.6.81, 6.12.18, 6.13.6, 6.14 Patch available CNA

CPE configurations NVD · 5

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.10.188 to before 5.11; 5.15.121 to before 5.15.179; 6.1.39 to before 6.1.130; 6.3.13 to before 6.4; 6.4.4 to before 6.6.81; 6.7 to before 6.12.18; 6.13 to before 6.13.6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:*6.14 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:*6.14 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:*6.14 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:*6.14 rc4VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.10.188 to before 5.11; 5.15.121 to before 5.15.179; 6.1.39 to before 6.1.130; 6.3.13 to before 6.4; 6.4.4 to before 6.6.81; 6.7 to before 6.12.18; 6.13 to before 6.13.6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc1:*:*:*:*:*:* Versions 6.14 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc2:*:*:*:*:*:* Versions 6.14 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc3:*:*:*:*:*:* Versions 6.14 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.14:rc4:*:*:*:*:*:* Versions 6.14 rc4 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.10.247, 5.15.179, 6.1.130, 6.4, 6.5
  • Fix · CNA Linux (Linux) Fixed in 5.10.247, 5.15.179, 6.1.130, 6.6.81, 6.12.18, 6.13.6, 6.14

Red Hat 3 advisories

  • RHSA-2025:11810 Released 2025-07-28 · Red Hat rating Important
    kernel security update
    • Red Hat CodeReady Linux Builder EUS (v.9.4) kernel-tools-libs-devel-5.14.0-427.79.1.el9_4, libperf-5.14.0-427.79.1.el9_4
    • Red Hat Enterprise Linux AppStream EUS (v.9.4) kernel-64k-debug-devel-5.14.0-427.79.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.79.1.el9_4, kernel-64k-devel-5.14.0-427.79.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool-7.3.0-427.79.1.el9_4, kernel-5.14.0-427.79.1.el9_4, kernel-64k-5.14.0-427.79.1.el9_4 +29
    • Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt-5.14.0-427.79.1.el9_4, kernel-rt-core-5.14.0-427.79.1.el9_4, kernel-rt-debug-5.14.0-427.79.1.el9_4 +9
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt-5.14.0-427.79.1.el9_4, kernel-rt-core-5.14.0-427.79.1.el9_4, kernel-rt-debug-5.14.0-427.79.1.el9_4 +11
  • RHSA-2025:10379 Released 2025-07-07 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.25.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.25.1.el9_6, kernel-64k-devel-5.14.0-570.25.1.el9_6 +12
    • Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.25.1.el9_6, kernel-64k-5.14.0-570.25.1.el9_6, kernel-64k-core-5.14.0-570.25.1.el9_6 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.25.1.el9_6, libperf-5.14.0-570.25.1.el9_6
    • Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.25.1.el9_6, kernel-rt-64k-5.14.0-570.25.1.el9_6, kernel-rt-64k-core-5.14.0-570.25.1.el9_6 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.25.1.el9_6, kernel-rt-core-5.14.0-570.25.1.el9_6, kernel-rt-debug-5.14.0-570.25.1.el9_6 +11
  • RHSA-2025:9079 Released 2025-06-16 · Red Hat rating Important
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-55.17.1.el10_0, kernel-64k-debug-devel-matched-6.12.0-55.17.1.el10_0, kernel-64k-devel-6.12.0-55.17.1.el10_0 +12
    • Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-55.17.1.el10_0, kernel-64k-6.12.0-55.17.1.el10_0, kernel-64k-core-6.12.0-55.17.1.el10_0 +28
    • Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-55.17.1.el10_0, libperf-6.12.0-55.17.1.el10_0
    • Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-55.17.1.el10_0, kernel-rt-64k-6.12.0-55.17.1.el10_0, kernel-rt-64k-core-6.12.0-55.17.1.el10_0 +21
    • Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-55.17.1.el10_0, kernel-rt-core-6.12.0-55.17.1.el10_0, kernel-rt-debug-6.12.0-55.17.1.el10_0 +11

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat CodeReady Linux Builder EUS (v.9.4)Fixed RHSA-2025:11810
Red Hat Enterprise Linux AppStream (v. 10)Fixed RHSA-2025:9079
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2025:10379
Red Hat Enterprise Linux AppStream EUS (v.9.4)Fixed RHSA-2025:11810
Red Hat Enterprise Linux BaseOS (v. 10)Fixed RHSA-2025:9079
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2025:10379
Red Hat Enterprise Linux BaseOS EUS (v.9.4)Fixed RHSA-2025:11810
Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)Fixed RHSA-2025:9079
Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)Fixed RHSA-2025:10379
Red Hat Enterprise Linux Real Time (v. 10)Fixed RHSA-2025:9079
Red Hat Enterprise Linux Real Time (v. 9)Fixed RHSA-2025:10379
Red Hat Enterprise Linux Real Time EUS (v.9.4)Fixed RHSA-2025:11810
Red Hat Enterprise Linux Real Time for NFV (v. 10)Fixed RHSA-2025:9079
Red Hat Enterprise Linux Real Time for NFV (v. 9)Fixed RHSA-2025:10379
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4)Fixed RHSA-2025:11810
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 8
  • Red Hat Enterprise Linux 9

Timeline

  1. 2026-10-02 Threatist record created from CVE-2025-21887
  2. 2026-10-03 Alias added: GHSA-vjwm-w9rc-f4cc

References

Patch 6

Other 1

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences