CVEvulnerability
CVE-2026-63816
7.8 HIGH
Official page ↗
- Status
- Undergoing Analysis
- Published
- 2026-07-19
- Last modified
- 2026-08-17
- Assigner
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
- CVSS 3.1 (416baaa9-dc9f-4396-8d5f-8c081fb06d67)
- 7.8 HIGH — CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode
- ioctl(F2FS_IOC_GARBAGE_COLLECT_RANGE) - shrink
- f2fs_gc
- gc_data_segment
- ra_data_block(cow_inode)
- mapping = F2FS_I(inode)->atomic_inode->i_mapping
: f2fs_is_cow_file(cow_inode) is true
- f2fs_evict_inode(atomic_inode)
- clear_inode_flag(fi->cow_inode, FI_COW_FILE)
- F2FS_I(fi->cow_inode)->atomic_inode = NULL
...
- truncate_inode_pages_final(atomic_inode)
- f2fs_grab_cache_folio(mapping)
: create folio in atomic_inode->mapping
- clear_inode(atomic_inode)
- BUG_ON(atomic_inode->i_data.nrpages)
We need to add a reference on fi->atomic_inode before using its mapping
field during garbage collection, otherwise, it will cause UAF issue.
References
- https://git.kernel.org/stable/c/56038756aae68312df00d4aa1d97e51ef3aca725 git.kernel.org
- https://git.kernel.org/stable/c/7d3ae21783e5914c1761ac7d63f882d3d70800e9 git.kernel.org
- https://git.kernel.org/stable/c/a499f77c06050a28c897bdbd86cd2f0721ae0743 git.kernel.org
- https://git.kernel.org/stable/c/a805fec35c201c59643ddcde713bce4051c8ee27 git.kernel.org
- https://git.kernel.org/stable/c/e0288584baa5dc41df4a829a023c4c1b33fe53d7 git.kernel.org