提交 dc6eb27b 编写于 作者: J Julia Lawall 提交者: Greg Kroah-Hartman

USB: host: Eliminate NULL dereference

The test above allows std to be NULL, so check that std is not NULL before
doing the dereference.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@r exists@
expression E,E1;
identifier f;
statement S1,S2,S3;
@@

if ((E == NULL && ...) || ...)
{
  ... when != if (...) S1 else S2
      when != E = E1
* E->f
  ... when any
}
else S3
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>
上级 6e1c3b46
......@@ -475,7 +475,7 @@ static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *u
|| (prev_end & (WHCI_PAGE_SIZE-1))
|| (dma_addr & (WHCI_PAGE_SIZE-1))
|| std->len + WHCI_PAGE_SIZE > QTD_MAX_XFER_SIZE) {
if (std->len % qset->max_packet != 0)
if (std && std->len % qset->max_packet != 0)
return -EINVAL;
std = qset_new_std(whc, qset, urb, mem_flags);
if (std == NULL) {
......
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