2022-11-16 09:58:29

by Peter Kosyh

Subject: [PATCH] scsi: myrs: check return value of dma_alloc_coherent() instead of using dma_mapping_error()

dma_alloc_coherent() may leave third parameter uninitialized. So
it is not safe to use dma_mapping_error() without checking return
value of dma_alloc_coherent().

Check the return value of dma_alloc_coherent() to detect
an error.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Peter Kosyh <[email protected]>
---
drivers/scsi/myrs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/myrs.c b/drivers/scsi/myrs.c
index 7eb8c39da366..1811c1a6385b 100644
--- a/drivers/scsi/myrs.c
+++ b/drivers/scsi/myrs.c
@@ -498,14 +498,14 @@ static bool myrs_enable_mmio_mbox(struct myrs_hba *cs,
/* Temporary dma mapping, used only in the scope of this function */
mbox = dma_alloc_coherent(&pdev->dev, sizeof(union myrs_cmd_mbox),
&mbox_addr, GFP_KERNEL);
- if (dma_mapping_error(&pdev->dev, mbox_addr))
+ if (!mbox)
return false;

/* These are the base addresses for the command memory mailbox array */
cs->cmd_mbox_size = MYRS_MAX_CMD_MBOX * sizeof(union myrs_cmd_mbox);
cmd_mbox = dma_alloc_coherent(&pdev->dev, cs->cmd_mbox_size,
&cs->cmd_mbox_addr, GFP_KERNEL);
- if (dma_mapping_error(&pdev->dev, cs->cmd_mbox_addr)) {
+ if (!cmd_mbox) {
dev_err(&pdev->dev, "Failed to map command mailbox\n");
goto out_free;
}
--
2.38.1

2023-04-20 19:15:25

by Alexey Khoroshilov

Subject: Re: [PATCH] scsi: myrs: check return value of dma_alloc_coherent() instead of using dma_mapping_error()

On 16.11.2022 12:41, Peter Kosyh wrote:
> dma_alloc_coherent() may leave third parameter uninitialized. So
> it is not safe to use dma_mapping_error() without checking return
> value of dma_alloc_coherent().
>
> Check the return value of dma_alloc_coherent() to detect
> an error.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Signed-off-by: Peter Kosyh <[email protected]>
> ---
> drivers/scsi/myrs.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/scsi/myrs.c b/drivers/scsi/myrs.c
> index 7eb8c39da366..1811c1a6385b 100644
> --- a/drivers/scsi/myrs.c
> +++ b/drivers/scsi/myrs.c
> @@ -498,14 +498,14 @@ static bool myrs_enable_mmio_mbox(struct myrs_hba *cs,
> /* Temporary dma mapping, used only in the scope of this function */
> mbox = dma_alloc_coherent(&pdev->dev, sizeof(union myrs_cmd_mbox),
> &mbox_addr, GFP_KERNEL);
> - if (dma_mapping_error(&pdev->dev, mbox_addr))
> + if (!mbox)
> return false;
>
> /* These are the base addresses for the command memory mailbox array */
> cs->cmd_mbox_size = MYRS_MAX_CMD_MBOX * sizeof(union myrs_cmd_mbox);
> cmd_mbox = dma_alloc_coherent(&pdev->dev, cs->cmd_mbox_size,
> &cs->cmd_mbox_addr, GFP_KERNEL);
> - if (dma_mapping_error(&pdev->dev, cs->cmd_mbox_addr)) {
> + if (!cmd_mbox) {
> dev_err(&pdev->dev, "Failed to map command mailbox\n");
> goto out_free;
> }
>

Reviewed-by: Alexey Khoroshilov <[email protected]>

Also you may want to add
Fixes: 77266186397c ("scsi: myrs: Add Mylex RAID controller (SCSI
interface)")

--
Alexey