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

A use after free vulnerability exists in the linux kernel such that dputupper is being called before ovldentryupdatereval, while upper-dflags was still accessed in ovldentryremote...

Astra Linux – Vulnerability found in Linux 6.1, Linux 6.12

In the Linux kernel, the following vulnerabilities have been resolved: ovl: Fixed a UAF Use-After-Free in ovldentryupdatereval by moving the dput function within ovllinkup. The issue arose because dputupper was called before ovldentryupdatereval, while upper-dflags was still accessed in...

SUSE CVE-2025-21887

In the Linux kernel, the following vulnerability has been resolved: ovl: fix UAF in ovldentryupdatereval by moving dput in ovllinkup The issue was caused by dputupper being called before ovldentryupdatereval, while upper-dflags was still accessed in ovldentryremote. Move dputupper after its last...