2024-04-03 01:40:27

by Huai-Yuan Liu

Subject: [PATCH] scsi: lpfc: Fix a possible null pointer dereference

In function lpfc_xcvr_data_show, the memory allocation with kmalloc might
fail, thereby making rdp_context a null pointer. In the following context
and functions that use this pointer, there are dereferencing operations,
leading to null pointer dereference.

To fix this issue, a null pointer check should be added. If it is null,
write error message and jump to 'out_free_rdp'.

Fixes: 479b0917e447 ("scsi: lpfc: Create a sysfs entry called lpfc_xcvr_data for transceiver info")
Signed-off-by: Huai-Yuan Liu <[email protected]>
---
drivers/scsi/lpfc/lpfc_attr.c | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
index b1c9107d3408..b11e5114b7f2 100644
--- a/drivers/scsi/lpfc/lpfc_attr.c
+++ b/drivers/scsi/lpfc/lpfc_attr.c
@@ -1904,6 +1904,11 @@ lpfc_xcvr_data_show(struct device *dev, struct device_attribute *attr,

/* Get transceiver information */
rdp_context = kmalloc(sizeof(*rdp_context), GFP_KERNEL);
+ if (!rdp_context) {
+ len = scnprintf(buf, PAGE_SIZE - len,
+ "ERROR: Not enough memory\n");
+ goto out_free_rdp;
+ }

rc = lpfc_get_sfp_info_wait(phba, rdp_context);
if (rc) {
--
2.34.1

2024-04-03 01:58:57

by Huai-Yuan Liu

Subject: Re: [PATCH] scsi: lpfc: Fix a possible null pointer dereference

Hi,

I'm a newbie in the Linux community. Due to my oversight, the patch I
submitted has an extra blank line, causing two consecutive emails to
lack a subject. However, these emails are identical in content to the
one with a subject. Please review the email with a subject. Apologies
for any confusion caused.

Thanks,
Liu.

2024-04-03 23:10:09

by Bart Van Assche

Subject: Re: [PATCH] scsi: lpfc: Fix a possible null pointer dereference

On 4/2/24 6:40 PM, Huai-Yuan Liu wrote:
> In function lpfc_xcvr_data_show, the memory allocation with kmalloc might
> fail, thereby making rdp_context a null pointer. In the following context
> and functions that use this pointer, there are dereferencing operations,
> leading to null pointer dereference.
>
> To fix this issue, a null pointer check should be added. If it is null,
> write error message and jump to 'out_free_rdp'.
>
> Fixes: 479b0917e447 ("scsi: lpfc: Create a sysfs entry called lpfc_xcvr_data for transceiver info")
> Signed-off-by: Huai-Yuan Liu <[email protected]>
> ---
> drivers/scsi/lpfc/lpfc_attr.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/scsi/lpfc/lpfc_attr.c b/drivers/scsi/lpfc/lpfc_attr.c
> index b1c9107d3408..b11e5114b7f2 100644
> --- a/drivers/scsi/lpfc/lpfc_attr.c
> +++ b/drivers/scsi/lpfc/lpfc_attr.c
> @@ -1904,6 +1904,11 @@ lpfc_xcvr_data_show(struct device *dev, struct device_attribute *attr,
>
> /* Get transceiver information */
> rdp_context = kmalloc(sizeof(*rdp_context), GFP_KERNEL);
> + if (!rdp_context) {
> + len = scnprintf(buf, PAGE_SIZE - len,
> + "ERROR: Not enough memory\n");
> + goto out_free_rdp;
> + }
>

Has this patch been verified with checkpatch? Checkpatch should have
reported the following for the above patch:

Possible unnecessary 'out of memory' message

Thanks,

Bart.

2024-04-07 07:01:52

by Huai-Yuan Liu

Subject: Re: [PATCH] scsi: lpfc: Fix a possible null pointer dereference

Hi.

The patch passed the checkpatch validation without reporting the
related information. I have sent the patch V2 email, thank you for
your suggestions.

Thanks,

Liu.