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@vger.kernel.org Fixes: 48a3103006631 ("wd719x: Introduce Western Digital WD7193/7197/7296 PCI SCSI card driver") Signed-off-by: Xiaomeng Tong xiam0nd.tong@gmail.com --- 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");