fs/ntfs3: Use __GFP_NOWARN allocation at wnd_init()

[ Upstream commit 0d0f659bf713662fabed973f9996b8f23c59ca51 ]

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
Reported-by: syzot <syzbot+fa4648a5446460b7b963@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/ntfs3/bitmap.c b/fs/ntfs3/bitmap.c
index 7f2055b..2a63793 100644 (file)
--- a/fs/ntfs3/bitmap.c
+++ b/fs/ntfs3/bitmap.c
@@ -666,7 +666,7 @@ 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;