[PATCH] drivers/scsi/qla4xxx: use scnprintf() instead of snprintf()

[PATCH] drivers/scsi/qla4xxx: use scnprintf() instead of snprintf()

[Jiapeng Zhong]

Fix the following coccicheck warning:

./drivers/scsi/qla4xxx/ql4_attr.c: WARNING: use scnprintf or
sprintf

The snprintf() function returns the number of characters which would
have been printed if there were enough space, but the scnprintf()
returns the number of characters which were actually printed.  If
the buffer is not large enough, then using snprintf() would result
in a read overflow and an information leak.

Reported-by: Abaci Robot<abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
---
 drivers/scsi/qla4xxx/ql4_attr.c | 22 +++++++++++-----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/scsi/qla4xxx/ql4_attr.c b/drivers/scsi/qla4xxx/ql4_attr.c
index ec43528..1a16017 100644
--- a/drivers/scsi/qla4xxx/ql4_attr.c
+++ b/drivers/scsi/qla4xxx/ql4_attr.c
@@ -170,7 +170,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 			char *buf)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
-	return snprintf(buf, PAGE_SIZE, "%s\n", ha->serial_number);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", ha->serial_number);
 }
 
 static ssize_t
@@ -178,7 +178,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 			   char *buf)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
-	return snprintf(buf, PAGE_SIZE, "%d.%02d\n", ha->fw_info.iscsi_major,
+	return scnprintf(buf, PAGE_SIZE, "%d.%02d\n", ha->fw_info.iscsi_major,
 			ha->fw_info.iscsi_minor);
 }
 
@@ -187,7 +187,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 			    char *buf)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
-	return snprintf(buf, PAGE_SIZE, "%d.%02d.%02d.%02d\n",
+	return scnprintf(buf, PAGE_SIZE, "%d.%02d.%02d.%02d\n",
 			ha->fw_info.bootload_major, ha->fw_info.bootload_minor,
 			ha->fw_info.bootload_patch, ha->fw_info.bootload_build);
 }
@@ -197,7 +197,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 		      char *buf)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
-	return snprintf(buf, PAGE_SIZE, "0x%08X\n", ha->board_id);
+	return scnprintf(buf, PAGE_SIZE, "0x%08X\n", ha->board_id);
 }
 
 static ssize_t
@@ -207,7 +207,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
 
 	qla4xxx_get_firmware_state(ha);
-	return snprintf(buf, PAGE_SIZE, "0x%08X%8X\n", ha->firmware_state,
+	return scnprintf(buf, PAGE_SIZE, "0x%08X%8X\n", ha->firmware_state,
 			ha->addl_fw_state);
 }
 
@@ -220,7 +220,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 	if (is_qla40XX(ha))
 		return -ENOSYS;
 
-	return snprintf(buf, PAGE_SIZE, "0x%04X\n", ha->phy_port_cnt);
+	return scnprintf(buf, PAGE_SIZE, "0x%04X\n", ha->phy_port_cnt);
 }
 
 static ssize_t
@@ -232,7 +232,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 	if (is_qla40XX(ha))
 		return -ENOSYS;
 
-	return snprintf(buf, PAGE_SIZE, "0x%04X\n", ha->phy_port_num);
+	return scnprintf(buf, PAGE_SIZE, "0x%04X\n", ha->phy_port_num);
 }
 
 static ssize_t
@@ -244,7 +244,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 	if (is_qla40XX(ha))
 		return -ENOSYS;
 
-	return snprintf(buf, PAGE_SIZE, "0x%04X\n", ha->iscsi_pci_func_cnt);
+	return scnprintf(buf, PAGE_SIZE, "0x%04X\n", ha->iscsi_pci_func_cnt);
 }
 
 static ssize_t
@@ -253,7 +253,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
 
-	return snprintf(buf, PAGE_SIZE, "%s\n", ha->model_name);
+	return scnprintf(buf, PAGE_SIZE, "%s\n", ha->model_name);
 }
 
 static ssize_t
@@ -261,7 +261,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 			  char *buf)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
-	return snprintf(buf, PAGE_SIZE, "%s %s\n", ha->fw_info.fw_build_date,
+	return scnprintf(buf, PAGE_SIZE, "%s %s\n", ha->fw_info.fw_build_date,
 			ha->fw_info.fw_build_time);
 }
 
@@ -309,7 +309,7 @@ void qla4_8xxx_free_sysfs_attr(struct scsi_qla_host *ha)
 {
 	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
 	qla4xxx_about_firmware(ha);
-	return snprintf(buf, PAGE_SIZE, "%u.%u secs\n", ha->fw_uptime_secs,
+	return scnprintf(buf, PAGE_SIZE, "%u.%u secs\n", ha->fw_uptime_secs,
 			ha->fw_uptime_msecs);
 }
 
-- 
1.8.3.1

Re: [PATCH] drivers/scsi/qla4xxx: use scnprintf() instead of snprintf()

[James Bottomley]

On Wed, 2021-01-20 at 15:22 +0800, Jiapeng Zhong wrote:
> Fix the following coccicheck warning:
> 
> ./drivers/scsi/qla4xxx/ql4_attr.c: WARNING: use scnprintf or
> sprintf
> 
> The snprintf() function returns the number of characters which would
> have been printed if there were enough space, but the scnprintf()
> returns the number of characters which were actually printed.  If
> the buffer is not large enough, then using snprintf() would result
> in a read overflow and an information leak.
> 
> Reported-by: Abaci Robot<abaci@linux.alibaba.com>
> Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
> ---
>  drivers/scsi/qla4xxx/ql4_attr.c | 22 +++++++++++-----------
>  1 file changed, 11 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/scsi/qla4xxx/ql4_attr.c
> b/drivers/scsi/qla4xxx/ql4_attr.c
> index ec43528..1a16017 100644
> --- a/drivers/scsi/qla4xxx/ql4_attr.c
> +++ b/drivers/scsi/qla4xxx/ql4_attr.c
> @@ -170,7 +170,7 @@ void qla4_8xxx_free_sysfs_attr(struct
> scsi_qla_host *ha)
>  			char *buf)
>  {
>  	struct scsi_qla_host *ha = to_qla_host(class_to_shost(dev));
> -	return snprintf(buf, PAGE_SIZE, "%s\n", ha->serial_number);
> +	return scnprintf(buf, PAGE_SIZE, "%s\n", ha->serial_number);

This is the wrong ABI to be replacing anything sysfs with, it should be
sysfs_emit()

James