CVE-2026-63816

Updated on 19 Jul 2026

Severity

Awaiting Analysis

Details

CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Overview

About vulnerability

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.

Details

Affected product:
AlmaLinux 9.2 ESU , TuxCare 9.6 ESU
Affected packages:
kernel @ 5.14.0 (+1 more)

Fixes

KernelCare state

Live-patch status from KernelCare for each operating system.

Operating system Status Covered kernels
Debian 13 Released
12 kernels
  • 6.12.85-1
  • 6.12.86-1
  • 6.12.88-1
  • 6.12.74-2
  • 6.12.73-1
  • 6.12.63-1
  • 6.12.69-1
  • 6.12.74-1
  • 6.12.90-1
  • 6.12.90-2
  • 6.12.94-1
  • 6.12.95-1