CVE-2026-74359
In the Linux kernel, the following vulnerability has been resolved: configfs_lookup(): don't leave ->s_dentry dangling on failure Normally ->s_dentry is cleared when dentry it's pointing to becomes negative (on eviction, realistically).
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.13%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: configfs_lookup(): don't leave ->s_dentry dangling on failure Normally ->s_dentry is cleared when dentry it's pointing to becomes negative (on eviction, realistically). However, that only happens if dentry gets to be positive in the first place; in case of inode allocation failure dentry never becomes positive, so ->d_iput() is not called at all. We do part of what normally would've been done by configfs_d_iput() (dropping the reference to configfs_dirent) manually, but we do not clear ->s_dentry there. Sloppy as it is, it does not matter in case of configfs_create_{dir,link}() - there configfs_dirent does not survive dropping the sole reference to it. However, for configfs_lookup() it *does* survive, with a dangling pointer to soon to be freed dentry sitting it its ->s_dentry. Subsequent getdents(2) in that directory will end up dereferencing that pointer in order to pick the inode number. Use after free... This is the minimal fix; the right approach is to set the linkage between dentry and configfs_dirent only after we know that we have an inode, but that takes more surgery and the bug had been there since 2006, so...
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.13% probability · 3th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/10da12d352b7b2bb330a8609fdda9a58bf0e9856
- https://git.kernel.org/stable/c/3e83b2203aa59bd279e4f677ec793d49dc9d019e
- https://git.kernel.org/stable/c/57088b06109f3222963c639d8d743f42c2899b13
- https://git.kernel.org/stable/c/9c747dcee164ead300de90550ad9e4122f0d1bbb
- https://git.kernel.org/stable/c/b6e9c82522ddaa3ac0706b295ff4a71975d4f883
- https://git.kernel.org/stable/c/c3b073a209a9baa691b744318ac929fecdd8847c
- https://git.kernel.org/stable/c/eee07d769da5ac4e4f7bd0bc17828646a318d499
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.