github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-07-27 17:47:41 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

fs/ntfs3: zero stale pagecache beyond valid data length

Browse Source 
Zero cached folios beyond the valid data length when closing a writable
mapping. This keeps cached data beyond initialized file contents zeroed
and prevents stale pagecache exposure after mmap-based writes.

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
This commit is contained in:
Konstantin Komarov 2026-05-22 14:46:23 +02:00
parent 33f29fc7c6
commit 4f165b1ff9
No known key found for this signature in database
GPG Key ID: A9B0331F832407B6
1 changed files with 28 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

30
fs/ntfs3/file.c
View File

@ -323,18 +323,44 @@ static int ntfs_extend_initialized_size(struct file *file,
return 0;
}
/* Zero pagecache after 'from'. */
static void ntfs_zero_tail(struct address_space *mapping, loff_t from)
{
struct folio_batch fbatch;
pgoff_t index = from >> PAGE_SHIFT;
unsigned nr, i;
folio_batch_init(&fbatch);
nr = filemap_get_folios(mapping, &index, -1, &fbatch);
for (i = 0; i < nr; i++) {
struct folio *folio = fbatch.folios[i];
u32 st = folio_pos(folio) < from ?
offset_in_folio(folio, from) :
0;
folio_lock(folio);
folio_zero_segment(folio, st, folio_size(folio));
folio_unlock(folio);
}
folio_batch_release(&fbatch);
}
static void ntfs_filemap_close(struct vm_area_struct *vma)
{
struct inode *inode = file_inode(vma->vm_file);
struct ntfs_inode *ni = ntfs_i(inode);
u64 i_size = i_size_read(inode);
u64 from = (u64)vma->vm_pgoff << PAGE_SHIFT;
u64 to = min_t(u64, i_size_read(inode),
from + vma->vm_end - vma->vm_start);
u64 to = min(i_size, from + vma->vm_end - vma->vm_start);
if (ni->i_valid < to) {
ni->i_valid = to;
mark_inode_dirty(inode);
}
ntfs_zero_tail(inode->i_mapping, ni->i_valid);
}
/* Copy of generic_file_vm_ops. */