From: Joe Perches > Sent: 01 September 2021 03:41 > > On Tue, 2021-08-31 at 21:15 +0300, Kari Argillander wrote: > > If we do not use kmalloc_array we get checkpatch warning. It is also > > little safer if something goes wrong with coding. > [] > > diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c > [] > > @@ -707,7 +707,7 @@ static struct NTFS_DE *hdr_find_e(const struct ntfs_index *indx, > > u16 *ptr; > > int new_slots = ALIGN(2 * nslots, 8); > > > > > > - ptr = kmalloc(sizeof(u16) * new_slots, GFP_NOFS); > > + ptr = kmalloc_array(new_slots, sizeof(u16), GFP_NOFS); > > if (ptr) > > memcpy(ptr, offs, sizeof(u16) * max_idx); > > This multiplication could also overflow. Not if kmalloc_array() has suceeded. OTOH the ALIGN(2 * nslots, 8) can also go wrong. (But probably not if the previous kmalloc() for 1/2 the size worked.) But there really ought to be some kind of bound check earlier. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
