CVE-2026-63816
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.
Affected versions
Linux kernel versions
5.18.18,
5.19
and later are affected. Fixed in
6.12.96,
6.18.39,
7.1.3,
7.2-rc1
and their respective stable series.
References
4 totalFrequently asked questions
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What is CVE-2026-63816?
CVE-2026-63816 is a unscored severity Linux kernel vulnerability . It affects Linux kernel versions from 5.18.18 onward and has been patched in 6.12.96, 6.18.39, 7.1.3 and others. CVE-2026-63816 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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Is there a patch available for CVE-2026-63816?
Yes — CVE-2026-63816 has been patched. Fixed versions include 6.12.96, 6.18.39, 7.1.3 and others. If you are running Linux kernel 5.18.18 or later up to the fix versions, apply the relevant patch for your kernel branch.
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Is CVE-2026-63816 actively exploited?
No — CVE-2026-63816 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.