On 32 bit systems a high value of op.count could lead to an integer overflow in the kzalloc() and gref_ids would be smaller than expected. If the you triggered another integer overflow in "if (gref_size + op.count > limit)" then you'd probably get memory corruption inside add_grefs().
Signed-off-by: Dan Carpenter <[email protected]> diff --git a/drivers/xen/gntalloc.c b/drivers/xen/gntalloc.c index f6832f4..23c60cf 100644 --- a/drivers/xen/gntalloc.c +++ b/drivers/xen/gntalloc.c @@ -280,7 +280,7 @@ static long gntalloc_ioctl_alloc(struct gntalloc_file_private_data *priv, goto out; } - gref_ids = kzalloc(sizeof(gref_ids[0]) * op.count, GFP_TEMPORARY); + gref_ids = kcalloc(op.count, sizeof(gref_ids[0]), GFP_TEMPORARY); if (!gref_ids) { rc = -ENOMEM; goto out; _______________________________________________ Virtualization mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/virtualization
