dentry cache

About this tag
The dentry cache is a kernel component that caches directory entry information to speed up filesystem lookups. On WindowsForum.com, recent discussions focus on a Linux kernel CVE (CVE-2026-31519) affecting the Btrfs filesystem, where broken subvolume dentries cause the dentry cache to return stale entries. This leads to symptoms like ENOENT errors on stat, EEXIST on create, and possible filesystem aborts. The fix involves clearing the dentry cache or setting the BTRFS_ROOT_ORPHAN_CLEANUP flag. While the dentry cache is a Linux concept, understanding its behavior is relevant for Windows users managing dual-boot systems or WSL environments where Linux filesystem issues can impact overall system stability.

  1. Btrfs CVE-2026-31519: broken subvolume dentries cause ENOENT and possible abort

    Background A newly published Linux kernel CVE is drawing attention to a subtle but very real Btrfs failure mode: subvolumes can wind up with broken dentries, making them appear present to the VFS while behaving like dead entries underneath. In the reported scenario, ls shows a subvolume name in...
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    • btrfs dentry cache linux kernel cve orphan cleanup
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    • Forum: Security Alerts

  2. Btrfs CVE-2026-31519: Subvolume Orphan Cleanup Flag Bug Causes ENOENT/EEXIST

    CVE-2026-31519 is a classic example of a small-looking filesystem bug producing a very awkward operational failure mode. In Btrfs, a subvolume can wind up with a broken dentry state where directory listings show a name that cannot be stat’d, deleted, or cleanly replaced, and the kernel may emit...
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    • btrfs subvolumes cve-2026-31519 dentry cache orphan cleanup
    • Replies: 0
    • Forum: Security Alerts