KMSAN reports an uninitialized value in longest_match_std(), invoked
from ntfs_compress_write(). When new folios are allocated without being
marked uptodate and ni_read_frame() is skipped because the caller expects
the frame to be completely overwritten, some reserved folios may remain
only partially filled, leaving the rest memory uninitialized.
Fixes: 584f60ba22f7 ("ntfs3: Convert ntfs_get_frame_pages() to use a folio")
Tested-by: syzbot+08d8956768c96a2c52cf@syzkaller.appspotmail.com
Reported-by: syzbot+08d8956768c96a2c52cf@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=08d8956768c96a2c52cf
Signed-off-by: Bartlomiej Kubik <kubik.bartlomiej@gmail.com>
---
fs/ntfs3/file.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ntfs3/file.c b/fs/ntfs3/file.c
index 4c90ec2fa2ea..00df27876c50 100644
--- a/fs/ntfs3/file.c
+++ b/fs/ntfs3/file.c
@@ -930,7 +930,7 @@ static int ntfs_get_frame_pages(struct address_space *mapping, pgoff_t index,
folio = __filemap_get_folio(mapping, index,
FGP_LOCK | FGP_ACCESSED | FGP_CREAT,
- gfp_mask);
+ gfp_mask | __GFP_ZERO);
if (IS_ERR(folio)) {
while (npages--) {
folio = page_folio(pages[npages]);
--
2.39.5