fs/ufs: avoid potential u32 multiplication overflow

The 64 bit ino is being compared to the product of two u32 values,
however, the multiplication is being performed using a 32 bit multiply so
there is a potential of an overflow.  To be fully safe, cast uspi->s_ncg
to a u64 to ensure a 64 bit multiplication occurs to avoid any chance of
overflow.

Fixes: f3e2a52 ("ufs: NFS support")
Signed-off-by: Colin Ian King <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Cc: Evgeniy Dushistov <[email protected]>
Cc: Alexey Dobriyan <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Addresses-Coverity: ("Unintentional integer overflow")
Signed-off-by: Linus Torvalds <[email protected]>

fs/ufs/super.c

@@ -101,7 +101,7 @@ static struct inode *ufs_nfs_get_inode(struct super_block *sb, u64 ino, u32 gene
 	struct ufs_sb_private_info *uspi = UFS_SB(sb)->s_uspi;
 	struct inode *inode;
 
-	if (ino < UFS_ROOTINO || ino > uspi->s_ncg * uspi->s_ipg)
+	if (ino < UFS_ROOTINO || ino > (u64)uspi->s_ncg * uspi->s_ipg)
 		return ERR_PTR(-ESTALE);
 
 	inode = ufs_iget(sb, ino);