2021-03-04 08:54:58

by Dinghao Liu

Subject: [PATCH] [v2] sata_dwc_460ex: Fix missing check in sata_dwc_isr

The return value of ata_qc_from_tag() is checked in the whole
kernel except for two calls in sata_dwc_isr(), which may lead
to null-pointer-dereference. Add return value checks to avoid
such case.

Signed-off-by: Dinghao Liu <[email protected]>
---

Changelog:

v2: - Refine commit message.
Add return value check for another ata_qc_from_tag() call.
---
drivers/ata/sata_dwc_460ex.c | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/drivers/ata/sata_dwc_460ex.c b/drivers/ata/sata_dwc_460ex.c
index 9dcef6ac643b..f0ef844428bb 100644
--- a/drivers/ata/sata_dwc_460ex.c
+++ b/drivers/ata/sata_dwc_460ex.c
@@ -543,6 +543,11 @@ static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)
hsdev->sactive_issued |= qcmd_tag_to_mask(tag);

qc = ata_qc_from_tag(ap, tag);
+ if (unlikely(!qc)) {
+ dev_err(ap->dev, "failed to get qc");
+ handled = 1;
+ goto DONE;
+ }
/*
* Start FP DMA for NCQ command. At this point the tag is the
* active tag. It is the tag that matches the command about to
@@ -658,6 +663,11 @@ static irqreturn_t sata_dwc_isr(int irq, void *dev_instance)

tag_mask &= (~0x00000001);
qc = ata_qc_from_tag(ap, tag);
+ if (unlikely(!qc)) {
+ dev_err(ap->dev, "failed to get qc");
+ handled = 1;
+ goto DONE;
+ }

/* To be picked up by completion functions */
qc->ap->link.active_tag = tag;
--
2.17.1

2021-03-04 14:14:19

by Jens Axboe

Subject: Re: [PATCH] [v2] sata_dwc_460ex: Fix missing check in sata_dwc_isr

On 3/3/21 12:34 AM, Dinghao Liu wrote:
> The return value of ata_qc_from_tag() is checked in the whole
> kernel except for two calls in sata_dwc_isr(), which may lead
> to null-pointer-dereference. Add return value checks to avoid
> such case.

Applied, thanks.

--
Jens Axboe