CVE-2026-63816: f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode
In the Linux kernel, the following vulnerability has been resolved:
f2fs: atomic: fix UAF issue on f2fsinodeinfo.atomicinode
- ioctl(F2FSIOCGARBAGECOLLECTRANGE) - shrink - f2fsgc - gcdatasegment - radatablock(cowinode) - mapping = F2FSI(inode)->atomicinode->imapping : f2fsiscowfile(cowinode) is true - f2fsevictinode(atomicinode) - clearinodeflag(fi->cowinode, FICOWFILE) - F2FSI(fi->cowinode)->atomicinode = NULL ... - truncateinodepagesfinal(atomicinode) - f2fsgrabcachefolio(mapping) : create folio in atomicinode->mapping - clearinode(atomicinode) - BUGON(atomicinode->idata.nrpages)
We need to add a reference on fi->atomicinode before using its mapping field during garbage collection, otherwise, it will cause UAF issue.
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-63816?
CVE-2026-63816 has a high severity rating of 7.8 according to CVSS 3.1.
What does CVE-2026-63816 affect?
CVE-2026-63816 affects the Linux kernel, specifically the f2fs file system.
How do I fix CVE-2026-63816?
To fix CVE-2026-63816, update to the latest stable version of the Linux kernel that addresses this vulnerability.
What type of vulnerability is CVE-2026-63816?
CVE-2026-63816 is a use-after-free (UAF) vulnerability related to f2fs_inode_info.atomic_inode.
What impact does CVE-2026-63816 have on systems?
CVE-2026-63816 can lead to potential information disclosure and system instability due to memory corruption.