CVE Catalog

CVE-2026-97949

Unknown
Published: Translated: NVD NIST

Summary

In the Linux kernel, the configfs system has an issue with rmdir. configfs_rmdir() leaves the dentry hashed after dropping the item, leading to use-after-free in configfs_symlink(). The fix unhashes the dentry before dropping the item.

Risk Assessment

Use-after-free can lead to system crash or potential privilege escalation. The issue occurs with concurrent symlink creation and directory removal.

Recommendation

Apply a Linux kernel update containing the fix for configfs. Restrict access to configfs operations to trusted users.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: configfs: unhash the dentry before dropping the item in rmdir configfs_get_config_item() treats a hashed dentry as proof that sd->s_element is a live config_item. configfs_rmdir() breaks that: simple_rmdir() leaves the dentry hashed, the last reference to the item is dropped right after, and the dentry is only unhashed by d_delete() once ->rmdir() has returned. configfs_symlink() resolves its target holding no lock on it, so get_target() can land in that window: BUG: KASAN: slab-use-after-free in config_item_get+0x26/0x90 get_target fs/configfs/symlink.c:128 [inline] configfs_symlink+0x4ab/0x1030 fs/configfs/symlink.c:185 Unhash in configfs_remove_dir(), while the item is still guaranteed to be there. A reference obtained just before that stays harmless, as create_link() rechecks CONFIGFS_USET_DROPPING, already set by configfs_detach_prep(). Both configfs_unregister_subsystem() paths d_drop() after detaching, so this only makes rmdir match them.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS