CVE-2026-63816
f2fs: atomic: fix UAF issue on f2fs_inode_info.atomic_inode
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.
INFO
Published Date :
July 19, 2026, 12:16 p.m.
Last Modified :
July 19, 2026, 12:16 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Affected Products
The following products are affected by CVE-2026-63816
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
Solution
- Update the Linux kernel to a version with the fix.
- Apply the specific patch for f2fs_inode_info.atomic_inode.
- Ensure proper reference counting for atomic_inode.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-63816.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-63816 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-63816
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-63816 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-63816 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Jul. 19, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '3db1de0e582c358dd013f3703cd55b5fe4076436', 'lessThan': '56038756aae68312df00d4aa1d97e51ef3aca725', 'versionType': 'git'}, {'status': 'affected', 'version': '3db1de0e582c358dd013f3703cd55b5fe4076436', 'lessThan': 'a499f77c06050a28c897bdbd86cd2f0721ae0743', 'versionType': 'git'}, {'status': 'affected', 'version': '3db1de0e582c358dd013f3703cd55b5fe4076436', 'lessThan': 'a805fec35c201c59643ddcde713bce4051c8ee27', 'versionType': 'git'}, {'status': 'affected', 'version': '3db1de0e582c358dd013f3703cd55b5fe4076436', 'lessThan': 'e0288584baa5dc41df4a829a023c4c1b33fe53d7', 'versionType': 'git'}, {'status': 'affected', 'version': '6db52f1944417c2601182a591a704e2f119c5215', 'versionType': 'git'}, {'status': 'affected', 'version': '5.18.18', 'lessThan': '5.19', 'versionType': 'semver'}], 'programFiles': ['fs/f2fs/gc.c', 'fs/f2fs/inode.c'], 'defaultStatus': 'unaffected'}, {'repo': 'https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git', 'vendor': 'Linux', 'product': 'Linux', 'versions': [{'status': 'affected', 'version': '5.19'}, {'status': 'unaffected', 'version': '0', 'lessThan': '5.19', 'versionType': 'semver'}, {'status': 'unaffected', 'version': '6.12.96', 'versionType': 'semver', 'lessThanOrEqual': '6.12.*'}, {'status': 'unaffected', 'version': '6.18.39', 'versionType': 'semver', 'lessThanOrEqual': '6.18.*'}, {'status': 'unaffected', 'version': '7.1.3', 'versionType': 'semver', 'lessThanOrEqual': '7.1.*'}, {'status': 'unaffected', 'version': '7.2-rc1', 'versionType': 'original_commit_for_fix', 'lessThanOrEqual': '*'}], 'programFiles': ['fs/f2fs/gc.c', 'fs/f2fs/inode.c'], 'defaultStatus': 'affected'}] Added 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. Added Reference https://git.kernel.org/stable/c/56038756aae68312df00d4aa1d97e51ef3aca725 Added Reference https://git.kernel.org/stable/c/a499f77c06050a28c897bdbd86cd2f0721ae0743 Added Reference https://git.kernel.org/stable/c/a805fec35c201c59643ddcde713bce4051c8ee27 Added Reference https://git.kernel.org/stable/c/e0288584baa5dc41df4a829a023c4c1b33fe53d7