CVE-2026-53368

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> f2fs: fix fsck inconsistency caused by incorrect nat_entry flag usage<br /> <br /> f2fs_need_dentry_mark() reads nat_entry flags without mutual exclusion<br /> with the checkpoint path, which can result in an incorrect inode block<br /> marking state. The scenario is as follows:<br /> <br /> create &amp; write &amp; fsync &amp;#39;file A&amp;#39; write checkpoint<br /> - f2fs_do_sync_file // inline inode<br /> - f2fs_write_inode // inode folio is dirty<br /> - f2fs_write_checkpoint<br /> - f2fs_flush_merged_writes<br /> - f2fs_sync_node_pages<br /> - f2fs_fsync_node_pages // no dirty node<br /> - f2fs_need_inode_block_update // return true<br /> - f2fs_fsync_node_pages // inode dirtied<br /> - f2fs_need_dentry_mark //return true<br /> - f2fs_flush_nat_entries<br /> - f2fs_write_checkpoint end<br /> - __write_node_folio // inode with DENT_BIT_SHIFT set<br /> SPO, "fsck --dry-run" find inode has already checkpointed but still<br /> with DENT_BIT_SHIFT set<br /> <br /> The state observed by f2fs_need_dentry_mark() can differ from the state<br /> observed in __write_node_folio() after acquiring sbi-&gt;node_write. The<br /> root cause is that the semantics of IS_CHECKPOINTED and<br /> HAS_FSYNCED_INODE are only guaranteed after the checkpoint write has<br /> fully completed.<br /> <br /> This patch moves set_dentry_mark() into __write_node_folio() and<br /> protects it with the sbi-&gt;node_write lock.