fs/ntfs3: Use __GFP_NOWARN allocation at wnd_init()

syzbot is reporting too large allocation at wnd_init() [1], for a crafted
filesystem can become wnd->nwnd close to UINT_MAX. Add __GFP_NOWARN in
order to avoid too large allocation warning, than exhausting memory by
using kvcalloc().

Link: https://syzkaller.appspot.com/bug?extid=fa4648a5446460b7b963 [1]
Reported-by: syzot <[email protected]>
Signed-off-by: Tetsuo Handa <[email protected]>
Signed-off-by: Konstantin Komarov <[email protected]>

Author: Tetsuo Handa

fs/ntfs3/bitmap.c

@@ -661,7 +661,7 @@ int wnd_init(struct wnd_bitmap *wnd, struct super_block *sb, size_t nbits)
 	if (!wnd->bits_last)
 		wnd->bits_last = wbits;
 
-	wnd->free_bits = kcalloc(wnd->nwnd, sizeof(u16), GFP_NOFS);
+	wnd->free_bits = kcalloc(wnd->nwnd, sizeof(u16), GFP_NOFS | __GFP_NOWARN);
 	if (!wnd->free_bits)
 		return -ENOMEM;