The bug is here:
if (SCB_out == scb->phys)
The list iterator 'scb' will point to a bogus position containing
HEAD if the list is empty or no element is found. This case must
be checked before any use of the iterator, otherwise it will lead
to a invalid memory access.
To fix this bug, add an check. Use a new variable 'iter' as the
list iterator, while use the old variable 'scb' as a dedicated
pointer to point to the found element.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 48a3103006631 ("wd719x: Introduce Western Digital WD7193/7197/7296 PCI SCSI card driver")
Signed-off-by: Xiaomeng Tong <xiam0nd.tong@xxxxxxxxx>
---
drivers/scsi/wd719x.c | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/drivers/scsi/wd719x.c b/drivers/scsi/wd719x.c
index 1a7947554581..6087ff4c05da 100644
--- a/drivers/scsi/wd719x.c
+++ b/drivers/scsi/wd719x.c
@@ -684,11 +684,15 @@ static irqreturn_t wd719x_interrupt(int irq, void *dev_id)
case WD719X_INT_SPIDERFAILED:
/* was the cmd completed a direct or SCB command? */
if (regs.bytes.OPC == WD719X_CMD_PROCESS_SCB) {
- struct wd719x_scb *scb;
- list_for_each_entry(scb, &wd->active_scbs, list)
- if (SCB_out == scb->phys)
+ struct wd719x_scb *scb = NULL, *iter;
+
+ list_for_each_entry(iter, &wd->active_scbs, list)
+ if (SCB_out == iter->phys) {
+ scb = iter;
break;
- if (SCB_out == scb->phys)
+ }
+
+ if (scb)
wd719x_interrupt_SCB(wd, regs, scb);
else
dev_err(&wd->pdev->dev, "card returned invalid SCB pointer\n");
--
2.17.1
