In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid potential...

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to avoid potential deadloop in f2fs_fsync_node_pages()

There is potential deadloop in race condition:

Thread A Thread B

• fsync
• f2fs_do_sync_file
• f2fs_fsync_node_pages
• last_fsync_dnode - folio_get(last_folio) - f2fs_setattr - f2fs_truncate - f2fs_truncate_blocks - f2fs_do_truncate_blocks - f2fs_truncate_inode_blocks - truncate_dnode - truncate_node - invalidate_mapping_pages - folio->mapping = NULL
• is_node_folio alwasy return false
• atomic && !marked is always true, then goto retry